We aimed to identify the risk factors associated with intra- and postoperative cerebrospinal fluid (CSF) leakage in pituitary adenomas treated with endoscopic transsphenoidal surgery.This study is a retrospective analysis of 250 pituitary adenoma cases from January 2017 to December 2019 at our hospital. All patients underwent endoscopic endonasal transsphenoidal surgeries. Univariate and multivariate analyses were performed to investigate the risk factors associated with intra- and postoperative CSF rhinorrhea.P < .001); intraoperative CSF leakage was an independent risk factor for postoperative CSF leakage . Chronic respiratory disease  was also an independent risk factor for postoperative CSF leakage. Vascularized septal mucosal flap was a protective factor .Eighty (32.0%) and nine (3.6%) patients had intra- and postoperative CSF leakage, respectively. Tumor size was an independent risk factor for intraoperative CSF leakage (odds ratio [OR], 1.229; 95% confidence interval [CI], 1.133–1.334; Intraoperative CSF leakage is more likely to occur in large pituitary adenomas. In the presence of intraoperative CSF leakage, postoperative CSF rhinorrhea is very likely to occur. Patients with chronic respiratory disease are also more likely to develop postoperative CSF leakage. The sellar base reconstructed using vascularized nasal septal flaps can significantly decrease the risk. The Knosp grade, degree of tumor resection, and postoperative use of a lumbar subarachnoid drain did not have any effects on postoperative CSF rhinorrhea. It is a reasonably safe procedure with low morbidity, particularly when performed by experienced surgeons.–4 However, postoperative cerebrospinal fluid (CSF) leakage is a major life-threatening complication following EETS, which may lead to meningitis or tension pneumocephalus, and is associated with prolonged hospitalization. The incidence of such complications ranges from 0.5 to 15% following EETS. Identifying the risk factors that affect the incidence of intra- and postoperative CSF leakage may help in decreasing the rates of these complications. In the present study, we retrospectively reviewed 375 serial cases of pituitary adenomas treated with EETS by a single surgeon. Our primary aim was to identify the predictors of intra- and postoperative CSF leakage in patients who underwent endoscopic resection of pituitary adenomas to better inform patients and educate surgeons on this potential complication.Pituitary adenomas account for 15% of all intracranial tumors.22.1A retrospective review of 315 consecutive patients with pituitary adenomas from January 2017 to December 2019 was conducted. All patients were followed up for 1 to 3 years, with an average follow-up period of 15.6 months. One surgeon (Y.J.) performed the initial EETS for all patients. This study was approved by the Ethics Committee of our hospital . The inclusion criteria were as follows: 1) a histological diagnosis of pituitary adenoma, 2) primary tumor, 3) complete resection of the tumor by EETS, 4) complete surgery performed by Y.J., and 5) complete medical records available. Patients with incomplete data, tumor recurrence, prior skull-base operation, or a history of radiation therapy or chemotherapy, were excluded from this study.The following data were collected retrospectively from the medical records: demographic data, including age, race, sex, and body mass index (BMI), comorbidity, patient history, and perioperative data including hypertension, diabetes mellitus, coronary heart disease, chronic pulmonary disease, and preoperative administration of bromocriptine. Furthermore, information regarding tumor characteristics including tumor size, consistency of the adenoma, adenoma pathology type, Knosp grade, hemorrhage into adenoma, and extent of tumor excision were also documented. Other recorded features included reconstructive techniques and the use of CSF diversion. The primary outcome was intra- and postoperative CSF leakage.2.2All patients underwent EETS for tumor resection. After infiltrating the local nasal mucosa with lidocaine and epinephrine, we commenced with bilateral middle turbinate reduction, and a vascularized nasal septal flap (VNSF) was then created for the large adenomas (≥10 mm). Diamond burs were used to shorten the posterior septum, and a sphenoidotomy was performed using a microdebrider until the back wall of the sphenoid and the borders of the sella turcica (sella) were visualized. The base of the sella range was located by a neuronavigator, and then opened using a high-speed drill and enlarged using rongeurs. A cruciate dural incision was created. Subsequently, the tumor was resected using suction and ring curettes within the pseudocapsule of the pituitary adenoma. To detect occult intraoperative CSF leakage before closure, we occasionally used the Valsalva maneuver.In the absence of CSF leakage during EETS, we performed either no packing or packing with absorbable hemostatic gauze (Surgicel) within the sella, covered by one layer of synthetic dura, followed by a layer of fibrin glue or VNSF (for large adenomas). If there is evidence of minor intraoperative CSF leakage, we utilized fat graft packing of the sella and carefully reconstructed the sella floor with one layer of synthetic dura + VNSF or a free graft harvested from the nasal mucosa (for microadenomas). The surface of the above three repair materials was usually fixed with fibrin glue. In cases of major CSF leakage, the same procedures as a minor CSF leakage repair was followed, with the addition of an immediate lumbar CSF diversion for 5 to 7 days. The sella was supported by a Foley balloon catheter (12–14 French) for 5 to 7 days.2.3The diagnosis of CSF leakage was made as follows. (I) For intraoperative CSF leak diagnosis: (1) intrasellar and/or parasellar outflow of a clear fluid, and (2) Valsalva maneuver as necessary. (II) For postoperative CSF leak diagnosis: (1) clinical nasal outflow and positive glucose outflow, and (2) nasal endoscopic examination as necessary. Postoperatively, patients with minor and intermittent CSF leakages were treated with bedrest (with the patient's head raised by 30 degrees), prophylactic antibiotics, and limited activities. Patients with major and persistent CSF leakages were treated with CSF diversion and lumbar drains. A lumbar drain was also performed for patients who did not improve after 7 days of bedrest. All patients who did not improve after CSF diversion treatment (≥7 days) were reoperated on via EETS.2.4t-test. Factors predictive of CSF leakage in the univariate analysis (P < .05) were entered into a stepwise binary logistic regression model to identify independent factors for intra- and postoperative CSF leakages. Statistical analysis was performed using SPSS . Statistical significance was set at P < .05.Categorical variables are presented as numbers and percentages and compared using the chi-squared test and Fisher exact test. Continuous variables are presented as means and standard deviations and compared using the two-sided unpaired 33.1Of the 315 consecutive patients diagnosed with pituitary adenomas, a total of 250 patients met the inclusion criteria and were included in this study from January 2017 to December 2019 at our institution. The average age of the patients was 44.1 ± 12.3 years. The mean hospitalization time was 8.4 days. The pathology included 187 (74.8%) non-functioning adenomas, 40 (16.0%) GH-secreting pituitary adenomas, 3 (1.2%) PRL-secreting pituitary adenomas, and 20 (8.0%) ACTH-secreting pituitary adenomas. There were 30 (12.0%) cases of microadenomas, 205 (82.0%) cases of macroadenomas, and 15 (6.0%) cases of giant adenomas.3.2Intraoperative CSF leakages were observed during surgery in 80 patients (32.0%), of the 80 cases with intraoperative leaks, 61 were minor CSF leaks. Postoperative CSF leaks occurred in nine patients (3.6%), including seven patients with intraoperative CSF leaks and two patients without any recognized intraoperative CSF leakage. Among the nine patients with postoperative CSF rhinorrhea, six patients were initially treated with 5 to 7 days of passive lumbar drainage, including bedrest, prophylactic antibiotics, and limited activities. The three patients required surgical repair via a trans-sphenoidal approach. The CSF leakage in all nine patients resolved. Four patients with postoperative CSF leaks were complicated with meningitis 2 to 7 days after EETS. Those patient received antibiotics (meropenem + vancomycin) for 14 days and were discharged from the hospital without any complications.3.3P = .013), (2) tumor size (P < .001), and (3) consistency of the adenoma (P = .032). Similarly, predictors of postoperative CSF leaks according to the univariate analysis were (Table P < .001), (2) degree of tumor resection (P = .011), and (3) intraoperative CSF leakage (P = .021). Only one factor was associated with a decreased postoperative CSF leakage rate, namely, the sella reconstructed by abdominal fascial graft + synthetic dura + VNSF (P < .001).In the univariate analysis, there were three factors associated with an increased intraoperative CSF leakage rate Table : (1) BMI3.4P <.001; OR, 1.229) was independently associated with an increased intraoperative CSF leakage rate. Similarly, multivariate analysis was performed using variables that significantly correlated with postoperative CSF leakage  and intraoperative CSF leakage  were independent risk factors for postoperative CSF leakage. In contrast, the use of VNSF + abdominal fat  was an independent protective factor for postoperative CSF leakage.Multivariate analysis was performed using variables that were significantly correlated with intraoperative CSF leakage. However, in the multivariate analysis Table , only thge Table . The res4,7–9 However, there are still some factors unrelated to surgical skills that could impact the rates of intra- and postoperative CSF leakages, and these have remained poorly defined. Our data suggested that certain factors may predict a greater likelihood of CSF leakage following EETS both intra- and postoperatively.EETS has continued to improve owing to recent advances in equipment, hemostatic agents, and closure techniques. The incidence of CSF leakage has been reduced to between 0.5% to 12% following EETS.,4,10 Thus, intraoperative CSF leakage seems to be an important risk factor for postoperative CSF leakage. Our results confirmed these findings. In our study, nine patients had postoperative CSF leakages. Among them, seven had intraoperative CSF leakages. The final multivariate regression analysis showed that intraoperative CSF leakage was an independent risk factor for postoperative CSF leakage .In most studies of pituitary adenomas and CSF leakages after transnasal surgery, researchers have found that postoperative CSF leakage occurred in most patients with intraoperative CSF leakage.P < .001). Zhou et al also reported a high incidence of intraoperative CSF leakage following a large pituitary adenoma resection. Their final multi-factor regression analysis demonstrated that it was an independent risk factor for intraoperative CSF rhinorrhea. Tumor size as a risk factor for CSF leakage during surgery may be due to suprasellar extension in large-sized tumors, which can lead to a rather thin diaphragm sellae. Therefore, gentle manipulation is necessary for large pituitary adenomas to avoid rupture of a rather thin diaphragm sellae during surgery. Removing the tumor in the following order—rear, two sides, and front—may avoid dropping the diaphragma sellae too early and too fast (which may lead to its rupture and consequently CSF leakage).Based on these results, to reduce the rate of postoperative CSF leakage, it is important to prevent intraoperative CSF leakage. Moreover, understanding the risk factors of intraoperative CSF leakage is beneficial in the management and prevention of postoperative CSF leakage. It is obvious that all the factors that can induce diaphragma sellae rupture can lead to CSF leakage. Thus, the factors impacting the rupture of the diaphragma sellae can also lead to intraoperative CSF leakage. We observed the significant difference in the tumor size between those who had an intraoperative CSF rhinorrhea and those who did not . To our knowledge, this has never been reported in the literature to date. This result may be related to the increased intracranial pressure during the acute onset of CRD. The increased intrathoracic pressure leading to decreased blood flow in the jugular vein, resulting in increased intracranial pressure, may cause herniation of the repaired material from the sellar base and thus, CSF leakage. Two other studies,12 have shown that an increased intracranial pressure plays an important role in the occurrence of postoperative CSF leakage or spontaneous CSF leakage. Hanba et al discovered that patients with asthma are more likely to have CSF leakage than patients without asthma after transnasal surgery. Furthermore, the rates of postoperative CSF leakage in these two groups were 4.7% and 2.7%, respectively. Moreover, Fleischman et al found that patients with obstructive sleep apnea were more likely to develop spontaneous CSF leakage.Our results revealed that CRD increased the risk of postoperative CSF leakage (OR, 57.5; ,13 have already reported that BMI was a risk factor for postoperative CSF leakage following EETS. However, the incidence of CSF leakage did not correlate with BMI in our series. Dlouhy et al and Karnezis et al both indicated that BMI was a risk factor for postoperative CSF leakage. However, the average BMI of the CSF leakage group compared with that of the non-CSF leakage group in these two studies was 33.1:30.3 kg/m2 and 39.2:32.9 kg/m2, respectively. In both studies, their patients’ average BMI was greater than 30 kg/m2. In our study, the average BMI was 21.80/21.66 kg/m2, which was lower than those in previous studies. We think it is possible that the average BMI in our patients was not elevated enough to lead to a spontaneous increase in intracranial pressure that results in postoperative CSF rhinorrhea. On the other hand, it is likely associated with the low variance of the evaluated sample in our study, which may also be one of the reasons that lead to our different conclusions .Previous studies–16 Currently, vascularized mucosal flaps has become a recognized method for sellar base reconstruction. The incidence of postoperative CSF leakage in our patients was significantly reduced by the use of VNFP and abdominal fascial graft. The blood supply of the VNFPs was mainly derived from the septal artery, which is rich in blood flow. Thus, the survival rate was higher than those in other non-vascular mucosal flaps. El-sayed et al also pointed out that the atrophy of the mucosa with a VNFP was smaller than that with a non-vascular mucosal flap, which was not enough to detach the mucosal flap from the sellar base.Some studies have suggested that a VNFP can reduce the incidence of postoperative CSF leakage to less than 6%.,18 Some researchers noted that the use of intraoperative lumbar subarachnoid drainage did not significantly reduce the postoperative CSF leakage rate.,19 However, Stokken et al indicated that in patients with a high-flow intraoperative CSF leakage, the use of a lumbar subarachnoid drain can immediately reduce the risk of postoperative CSF leakage. Conversely, our study found that such use did not significantly reduce the risk of postoperative CSF leakage. Moreover, using a lumbar subarachnoid drain can easily lead to intracranial infection and prolonged hospitalization. Thus, careful consideration is required when using a lumbar subarachnoid drain intraoperatively to prevent postoperative CSF leakage.Whether the use of lumbar subarachnoid drains reduces the rates of postoperative CSF rhinorrhea remains controversial. However, for the patients with postoperative CSF leakage, four of them developed intracranial infection, the rates of intracranial infection after postoperative CSF leakage was about 44.4%, which was similar to that Michael E. Ivan and his colleagues reported in their study. The leakage of CSF to the sinuses increases exposure to the normal flora in the nasopharynx, then leads to infection, so the use of antibiotics should be more aggressive in patients with postoperative cerebrospinal fluid leakage.In present study, six of nine patients with postoperative CSF leakage were cured with lumbar drainage treatment, the effective rate of lumbar drainage for postoperative cerebrospinal fluid leakage was about 67%. For the treatment of postoperative CSF leakage, the effect of lumbar drains is obvious. Lumbar drains has been indicated to decrease the pressure, which could lower the chance of persistent CSF fistula.4.1This study has some limitations. First of all, this is a retrospective analysis, we need to design a randomized controlled clinical trial in the future to further verify the reliability of our results in present study. The other limitation is that we did not compare and analyze the cerebrospinal fluid leakage in other types of tumors, such as craniopharyngioma, tuberculum sella meningioma, rathke cyst, which is also the focus of our future research.5During nasal transsphenoidal endoscopic resection of pituitary adenomas, patients with a large tumor should be strictly monitored for intraoperative CSF leakage. In the presence of intraoperative CSF leakage, the sellar base defects should be carefully repaired to avoid postoperative CSF leakage. The sella constructed by abdnominal fat + VNFP may lower the rate of postoperative CSF leakage. As such, a VNSF should be created ahead of time for these patients. For patients with CRD, postoperative management must be provided with caution. Respiratory management is necessary to reduce inflammatory reactions in the postoperative period. These measures can effectively reduce the incidence of postoperative CSF leakage in patients who are preparing for transnasal sphenoidal endoscopic surgery for pituitary adenomas.YP conceived and designed the study. MW and YC performed the statistical analyses. YJ, MW, and YC contributed to data collection and interpretation, as well as drafting and critically revising the manuscript. All authors approved the final version of the manuscript and are accountable for the accuracy and integrity of all aspects of the study.Conceptualization: Ming Wang.Data curation: Ming Wang, Yang Cai, Yugang Jiang, Yong Peng.Formal analysis: Yugang Jiang, Yong Peng.Investigation: Yong Peng.Methodology: Ming Wang, Yong Peng.Project administration: Ming Wang.Resources: Ming Wang, Yang Cai, Yong Peng.Software: Ming Wang, Yang Cai, Yong Peng.Validation: Ming Wang, Yugang Jiang, Yong Peng.Writing – original draft: Ming Wang.Writing – review & editing: Ming Wang, Yong Peng.


NecessaA 57-year-old male patient underwent aortic valve replacement because of severe aortic regurgitation at a referring hospital at 38 years of age. In the subsequent 9 years, he underwent 4 reoperations because of recurrent endocarditis. After progressive decline of his left ventricular (LV) function, he was transferred to our center and listed for HTx.A donor heart became available of a young man in his mid-twenties, presumed previously healthy. He was diagnosed with pulmonary embolism after a long-distance flight, which led to an out-of-hospital cardiac arrest with pulseless electrical activity. Echocardiography showed a severely dilated right ventricle (RV) with poor function and LV cavitary obliteration. After resuscitation, he was hemodynamically stable and transported to the intensive care unit. Unfortunately, he was severely neurologically damaged, and brain death was diagnosed after 2 days. Based on serial echocardiography that showed a recovered RV, the heart was accepted for donation and a donor procedure was started.Donor heart procurement was uneventful. Because of the 5 previous sternotomies and a high likelihood of a complicated recipient cardiectomy, to limit cold ischemia time, the recipient operation was started as soon as the heart was accepted at the donor site. Upon arrival to our hospital, it became apparent that a cancerous process was present in the retroperitoneum of the donor, which had not been recognized earlier by conventional imaging and inspection. Pathology of this process showed a mixed germ cell cancer . Donor post-procedure blood results showed elevated values for both alfa-fetoprotein (αFP) and human chorionic gonadotropin (hCG). The diagnosis of metastatic testicular germ cell cancer (TGCC) in the donor was made.Unfortunately, the diagnosis of metastatic TGCC came after the recipient surgical team had already started cardiectomy of the recipient, reaching a point of no return. Although any possibility of cancer transmission to a transplant recipient should be avoided, it was decided that there was no other option than to continue with the transplantation. An oncologist specializing in TGCC was consulted. The risk of poor outcome with venoarterial extracorporeal membrane oxygenation and waiting for an urgent donor heart was thought to be greater than the risk of transmission of TGCC, given the significant shortage of donor hearts and relatively high waiting list mortality. Additional irrigation of the heart was performed to remove as many intravascular cells as possible. Implantation of the donor heart was uneventful. Immunosuppression was started as usual—tacrolimus, mycophenolate mofetil (MMF), and prednisolone—in combination with increased oncological surveillance.Temporary venoarterial extracorporeal membrane oxygenation support because of RV failure and hemofiltration was necessary for 3 days. The patient was extubated on day 6 and then transferred to the cardiology ward on day 9 post-operatively. He recovered quickly and had normal cardiac function and rhythm. Routine endomyocardial biopsy on days 16 and 23 showed 1R cellular rejection, for which prednisolone tapering was deferred, and he remained at a dose of 20 mg/day. Thereafter, endomyocardial biopsy normalized and surveillance for clinical stage 1 TGCC was initiated by the oncologist. Two months after HTx, serum tumor markers (αFP and hCG) were normal. Computed tomography (CT) of the chest and abdomen did not show any metastases, and ultrasound of the testes was normal as well.Three months after HTx, pathological examination of a routine endomyocardial biopsy showed embryonal carcinoma, without signs of rejection of the heart or cellular infiltrate in the tumor  patients, and none with TGCC . Data onAn important issue is the donor screening of the previously healthy young male with massive pulmonary embolism after a long-distance flight. Although not regarded as truly “unprovoked” in our case, occult cancer can be found in 5% of patients with unprovoked thromboembolism . In retr. Although a switch to sirolimus was considered given its potentially antineoplastic properties, 2 important arguments were raised against its use: 1) its efficacy in TGCC is questionable  The presented patient died acutely of toxicities such as neutropenia and mucositis, but with a primary cause of death being the cardiac arrest and its sequelae. It can certainly not be excluded that necrosis in the cardiac tumor was the trigger for cardiac arrhythmias, although not observed during chemotherapy administration. In summary, we report the case of a patient in whom a heart and a potentially curable tumor were transplanted. Unfortunately, the recipient of each died.The authors have reported that they have no relationships relevant to the contents of this paper to disclose.


Delirium was assessed by the Confusion Assessment Method. The hip fracture cohort had higher CSF levels of noradrenaline and adrenaline than the two other cohorts (both P < 0.001). Within the hip fracture cohort those with delirium (n = 65) had lower CSF adrenaline and dopamine levels than those without delirium . Similarly, the medical delirium patients had lower CSF dopamine levels than the cognitively normal elderly (P < 0.001). Age did not correlate with the CSF catecholamine levels. These findings with lower CSF dopamine levels in hip fracture- and medical delirium patients challenge the theory of dopamine excess in delirium and question use of antipsychotics in delirium. The use of alpha-2 agonists with the potential to reduce noradrenaline release needs further examination.Dopamine and noradrenaline are functionally connected to delirium and have been targets for pharmacological interventions but the biochemical evidence to support this notion is limited. To study the CSF levels of dopamine, noradrenaline and the third catecholamine adrenaline in delirium and dementia, these were quantified in three patient cohorts: (i) cognitively normal elderly patients ( Delirium, or ‘acute confusion’, is a common complication of acute illness in the elderly, for which there is no established treatment. Disturbance in three signalling substances, referred to as catecholamines, is suspected in delirium. Here, Henjum et al. studied CSF catecholamine levels and report alterations relevant for delirium treatment.  To answer this study question CSF catecholamine levels were analysed (i) in hip fracture patients with and without delirium and dementia; (ii) in a second delirium group with delirium precipitated by another medical condition, and (iii) in cognitively normal elderly patients as a reference.,Hip fracture patients were recruited from the Oslo Orthogeriatric Trial (OOT) that included patients admitted to Oslo University Hospital from 2009 to 2012. The OOT was a randomized controlled trial evaluating the effect of an orthogeriatric service on delirium-associated long-term cognitive decline. All CSF samples available from this trial were included in the current study. During the hospital stay, delirium was assessed daily and until the fifth post-operative day by the Confusion Assessment Method.n = 118) were grouped according to the presence of delirium at any time during the hospital stay (yes/no) and secondarily according to delirium status when CSF was sampled  and to pre-fracture dementia status (The patients (a status .n = 13), for dopamine; antiparkinsonian agents , antipsychotics  and relevant antidepressants , in total 20 patients due to medication overlap). No patients were prescribed MAO-A inhibitors or bupropion (N06A G and X12).In sensitivity analyses, we excluded patients receiving medications directly related to the transmitter systems of interest, for noradrenaline and adrenaline relevant antidepressants . Delirium was assessed either by the study physician by the Confusion Assessment Method (CAM), or by clinical evaluation of the treating physician. Dementia status was set from the hospital records. These patients formed a separate delirium group labelled ‘medical delirium’.The medical patients were recruited from a prospective study at the same hospital from 2014 to 2015A group of cognitively unimpaired  elderly were recruited in 2012 and 2013 from patients scheduled for orthopaedic, urological or gynaecological elective surgery in spinal anaesthesia at Oslo University Hospital or Diakonhjemmet Hospital.Standard protocol approvals, registrations and patient consents. The study was performed in accordance with the Declaration of Helsinki. Informed consent was obtained from the patient or the closest relative if the patient was unable to give consent. The study was approved by the Regional Committee for Ethics in Medical and health research in Norway .For the hip fracture and the elective surgery patients, CSF was collected in connection with the surgery at the onset of spinal anaesthesia before administration of the anaesthetic agents. For the medical delirium patients, CSF was obtained in conjunction with the diagnostic LP at a median of one day after CNS symptom development. Hip fracture surgeries were performed at all hours see . Electivin situ Ag/AgCl) reference electrode and an auxiliary electrode. The working potential between the working electrode and the auxiliary electrode was set to +0.60 V, range at 50 nA and sensitivity 10 nA. The HPLC conditions were Agilent analog/digital converter (ADC unit nA) units/volt 50.000 and peak width 0.133 min (data rate 2 Hz). Mobile phase flow; 1.0 ml/min, injection interval 15 min, the compressibility 100 × 10−6/bar, column temperature 40.0°C, injection volume 10.0 µl and run time 12 min. Mobile phase, calibration standard and internal standard reagents came from the same company, Chromsystem GmbH .The CSF concentrations of noradrenaline, adrenaline and dopamine were analysed in a single batch for each variable by means of an isocratic high-performance liquid chromatography  system with a reversed-phase C-18 column  and an electrochemical detection . The ECD had a three-electrode configuration system with a glassy carbon flow cell, an  as informed by the suppliers  for quantification of plasma catecholamines. This was here applied as CSF and plasma have comparable matrixes in HPLC-ECD analyses.CSF samples were directly injected into the HPLC-ECD system (no CSF pre-preparation with solid-phase extraction- or sample clean-up columns) and run after the calibration standards. Peak for each component was integrated and identified from calibration retention time and the peak heights related to a concentration from the same standard.A quality control (a CSF control pool) was injected for every tenth injection. The inter-assay coefficients of variation , were 4.7%, 6.2% and 8.3% for noradrenaline, adrenaline and dopamine, respectively.RS). The significance level was set at 0.05 and reported P-values are two-tailed.The data were not normally distributed as judged by visual inspection and tests for normality (Shapiro–Wilk and Kolmogorow–Smirnov). Non-parametric analyses were, therefore, applied with central tendency and spread reported by median and the interquartile range (IQR). Group differences were analysed by Mann–Whitney or Kruskal–Wallis tests, and correlations by Spearman’s correlation coefficient . Graphical illustrations were created with GraphPad Prism .The data that support the findings of this study are available from the corresponding author upon reasonable request.RS = 0.58 P < 0.001, n = 266) and similarly in the three individual cohorts. CSF dopamine correlated with noradrenaline and adrenaline only in the hip fracture cohort .Noradrenaline, adrenaline and dopamine were detectable in all CSF samples in all three cohorts. CSF noradrenaline and adrenaline correlated positively among all patients . The CSF catecholamine levels did not differ between the genders in the hip fracture cohort . Cognitively normal elderly females had higher CSF dopamine levels than males (2.9 (1.9–3.5) versus 2.3 (1.7–3.0), U = 1437, P = 0.03, n = 60, n = 62)), but there were no differences in the CSF levels of noradrenaline and adrenaline . Acute hip fracture surgery and diagnostic LPs were performed at all hours but the CSF catecholamine levels did not differ in samples collected at different time intervals during the day  = 89.7, P < 0.001, n = 266, P < 0.001, n = 155 and H(2) = 12.09, P = 0.002, n = 111).The cognitively normal elderly, medical delirium and hip fracture patients presented with distinct differences in the CSF catecholamine levels. While the hip fracture patients had the highest CSF levels of noradrenaline and adrenaline, CSF dopamine levels were highest among the cognitively normal elderly (H(2) = 111.9, 26.0 and 46.5 respectively all P = 0.03 and U = 1129.5, P = 0.002, respectively, n = 65 versus n = 52, As the higher levels of the adrenergic transmitters in the hip fracture patients could relate to the hip fracture further analyses of delirium and dementia among these patients were performed within this cohort. About half of the hip fracture patients experienced delirium during the hospital stay. These had lower levels of CSF adrenaline and dopamine than those without delirium  after exclusion of patients on relevant medications (see methods). The hip fracture patients were, therefore, divided according to pre-fracture dementia status for further analyses.Patients with pre-fracture dementia had lower CSF levels of adrenaline and dopamine than patients without pre-fracture dementia . In the pre-fracture dementia strata, the medians were lower in both the incident and prevalent delirium groups but not significantly different (The majority of the hip fracture patients with delirium had delirium superimposed on dementia (∼75%), while most patients without pre-fracture dementia did not develop delirium ∼75%, . When deifferent . ExcludiP < 0.001, n = 122 versus n = 26, P < 0.001, n = 122, n = 17) and when analysing males and females separately (data not shown). The medical delirium patients and cognitively normal elderly had similar CSF noradrenaline and adrenaline levels (U = 1379.5, P = 0.30 and U = 1575, P = 0.96, n = 122 versus n = 26, Medical delirium patients had lower CSF dopamine levels than the cognitively normal elderly (U = 725, P = 0.48, n = 65 versus n = 26, P < 0.001 and U = 621, P = 0.049, n = 65 versus n = 26, CSF dopamine levels were similar in patients with delirium precipitated by a hip fracture and another medical condition (U = 765, We examined central catecholamine activity by the CSF levels in delirium with or without pre-existing dementia in hip fracture patients, medical delirium patients and cognitively normal elderly. All three catecholamines were detected and quantified in CSF from all patients. The three cohorts presented with distinctly different catecholamine levels that seemed influenced by delirium and dementia.,,The hip fracture patients differed from the other two cohorts with higher CSF levels of the adrenergic transmitters, in particular noradrenaline, consistent with activation of these systems by pain and stress.,Contrasting the anticipation of excessive dopaminergic activity in delirium,The hip fracture patients with dementia, the majority with delirium superimposed on dementia, had lower CSF levels of adrenaline and dopamine. Lower CSF dopamine align with dopamine reductions in dementia in post-mortem studies,,Activated in arousal, attention and at wake, noradrenaline clinically relates to delirium. Dexmedetomidine is an α2-agonist with analgesic, sedative and anxiolytic effects attributed to stimulation of α2-autoreceptors in the locus coeruleus and spinal cord, mediating negative feedback thus reducing noradrenaline release.A strength of this study is the large sample size allowing for subgrouping of patients based on delirium status at the time of CSF sampling and pre-fracture dementia status. Still, although a large study in the context of delirium, the number of individuals in some subgroup analyses was limited. This may increase the likelihood of false negative but also false positive results.,,The retrospective classification of dementia without further information on dementia aetiology is a limitation of the study. People with Dementia with Lewy bodies may have higher CSF noradrenaline levels than other dementias and a higher risk of delirium.Catecholamine activity was assessed by the CSF noradrenaline, adrenaline and dopamine levels. Hip fracture and medical delirium patients presented with lower CSF dopamine levels but dementia and delirium alterations overlapped in the hip fracture patients. In patients without pre-fracture dementia CSF noradrenaline was higher in incident delirium although not statistically significant. These findings should be replicated in larger studies but are in line with restricting the use of antipsychotics for delirium patients and further exploring use of α2-agonists.Brain Communications online.fcab121_Supplementary_DataClick here for additional data file.


Successful aging depends on avoiding disease and disability, maintaining high physical and cognitive function, and psychological adaptation. Research examining the relationship of pet ownership (PO) or human-animal interaction (HAI) to human health supports contributions to these successful ag-ing-related outcomes at some point in the life-cycle, mostly in populations with diseases or disabili-ties. We examine the contributions of PO to maintaining physical capacity among generally healthy community-dwelling older participants in the Baltimore Longitudinal Study of Aging (BLSA). Partici-pants’  completed a standardized physi-cal function test battery (among other measures) every 1-4 years and a ten-year PO history. Linear mixed, or generalized linear mixed, models with time varying PO were used to examine change in successful aging-related outcomes over up to 13 years  according to PO. Physi-cal function declined across all domains examined, but was observed to be less severe with PO in overall physical performance (p<0.001), rapid gait speed (p=0.041), 400-meter walk time (p<0.001), and reported physical wellbeing (p=0.032). No differences were observed for grip strength (p=0.56), usual gait speed (p=0.07), and leisure time physical activity (p=0.26) after con-trolling for age. This study provides the first longitudinal evidence that PO may promote successful aging among community-dwelling healthy older adults by moderating age-related declines in physical functional status in late-life.


The benzodiazepine midazolam is a γ-aminobutyric acid (GABA)-A receptor agonist frequently used for sedation or stress control in patients suffering from traumatic brain injury (TBI). However, experimental studies on benzodiazepines have reported divergent results, raising concerns about its widespread use in patients. Some studies indicate that benzodiazepine-mediated potentiation of GABAergic neurotransmission is detrimental in brain-injured animals. However, other experimental investigations demonstrate neuroprotective effects, especially in pretreatment paradigms. This study investigated whether single-bolus midazolam administration influences secondary brain damage post-TBI.Two different midazolam dosages (0.5 and 5 mg/kg BW), a combination of midazolam and its competitive antagonist flumazenil, or vehicle solution (NaCl 0.9%) was injected intravenously to mice 24 h after experimental TBI induced by controlled cortical impact. Mice were evaluated for neurological and motor deficits using a 15-point neuroscore and the rotarod test. Histopathological brain damage and mRNA expression of inflammatory marker genes were analyzed using quantitative polymerase chain reaction three days after insult.IL-1β mRNA levels due to postinjury application of midazolam was reversible by flumazenil administration. However, other inflammatory parameters were not affected.Histological brain damage was not affected by posttraumatic midazolam administration. Midazolam impaired functional recovery, and this effect could not be counteracted by administering the midazolam antagonist flumazenil. An increase in This study merely reports minor effects of a postinjury midazolam application. Further studies focusing on a time-dependent analysis of posttraumatic benzodiazepine administration are required. Patients suffering from traumatic brain injury (TBI) need sedation to induce anxiolysis, prevent agitation, and allow mechanical intubation –3. BenzoStudies have reported divergent results regarding the disadvantages/advantages of benzodiazepines in the peritraumatic phase. There is extensive evidence indicating that potentiation of GABAergic transmission is detrimental in brain-injured animals . Posttrahalf-time with rapid onset and offset of action  [Tissue samples of the right upper quadrant  from the brain sections of injured brains were collected during histological processing and snap-frozen in liquid nitrogen as previously described . SamplesData were analyzed using the Sigma Plot 13 Statistical Software package . Exact Wilcoxon–Mann–Whitney tests were performed. Values were adjusted for multiple comparisons using the Holm–Bonferroni method. Data are expressed as mean ± SD. A P level of <0.05 was considered statistically significant. Previously published data from our research group were used to calculate the number of animals. For the primary outcome “lesion volume“ we calculated a group size number of n = 10 when expecting a biological effect by 30%, an α error of 0.05 and a statistical power of 0.9.P = 0.007 for low-dose midazolam versus vehicle, P < 0.001 for high-dose midazolam versus vehicle group, and P < 0.001 for high-dose midazolam versus midazolam plus flumazenil; Fig. The injected doses of midazolam did not induce deep sedation. The animals were tested for loss of righting reflex (LORR) and the duration was recorded. Both dosages of midazolam induced a short-lasting LORR effect, whereas the injection of the vehicle, or the mixture of midazolam and its antagonist flumazenil, had no effect on the LORR  and trended towards increased neurological deficits in the high-dose midazolam group  compared with vehicle-treated mice (3.1 ± 1.5 points). This effect was not influenced by the antagonist flumazenil . Similar to the neuroscore results, this effect remained unaffected by flumazenil administration . The mRNA expression levels of TNF-α, IL-6, and iNOS were not influenced by midazolam treatment.We quantified the mRNA expression levels of the proinflammatory marker genes ues Fig. . All aniIL-1β mRNA levels significantly compared to the control groups.Short-acting benzodiazepines such as midazolam are commonly used to manage patients with TBI –24. In tBenzodiazepines remain the core medication for sedation in the ICU or surgical procedures. Short-acting agents such as midazolam are frequently used to treat seizures, acute mania, motor agitation, and other psychiatric emergencies in the TBI population. In brain injury, the effects of benzodiazepines are complex. Some clinicians consider benzodiazepines as a group of potentially detrimental medications for patients suffering from stroke or TBI –26. A stIL-1β three days after TBI. This was reversed by flumazenil administration. An interaction between inflammatory mediators and excitatory signaling was demonstrated by blockading the glutamate NMDA receptor, thereby suppressing neuroinflammation after TBI [Other experimental studies demonstrated that GABA-A modulators, such as benzodiazepines and propofol, may induce neurotoxicity in the young and developing brain –31. Thesfter TBI , 38.Currently, there are limited patient data on the impact of sedation or anesthesia on the outcome to facilitate surgery or intensive care therapy after acute cerebral injury or ischemia. A clinical study investigating cerebral biomarkers by microdialysis in patients suffering from severe TBI reported no difference in the metabolic profile between patients receiving propofol or midazolam sedation during the acute phase of TBI . ConsistIn summary, our data suggest that midazolam, in contrast to propofol, does show a delayed neurotoxic effect in injured brain tissue. The present study therefore adds important information for future clinical studies to identify sedative with a low neurotoxic profile for the treatment of brain injury patients.IL-1β mRNA expression levels by postinjury application of midazolam was reversible by flumazenil application. However, other inflammatory parameters remained unaffected. Therefore, our study results suggest a minor influence of single-bolus administration of midazolam on delayed pathophysiological mechanisms.The present study investigated a single administration of midazolam in TBI using a highly standardized CCI model. We could not demonstrate an effect on histological brain damage by posttraumatic midazolam administration. Midazolam administration impaired functional recovery, and the administration of midazolam antagonist flumazenil could not counteract this effect. An increase in


To evaluate the usefulness of CSF and plasma neurofilament light (Nf-L) as a biomarker for human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy (HAM).Nf-L, CXCL10, and neopterin were measured by ELISA in 83 CSF samples obtained from 49 individuals living with HTLV-1/2. Plasma Nf-L was also measured by single molecule array. Results were correlated with duration of disease, age, mobility, CSF cell counts, CSF protein, and HTLV-1 proviral load.p < 0.0015). There was an inverse correlation between Nf-L and duration of disease . Wheelchair-dependent patients had high concentrations of markers of inflammation and neuronal damage. Concentrations of CXCL10, neopterin, and Nf-L remained elevated in follow-up samples (mean follow-up 5.2 years). Nf-L in plasma correlated with concentration of Nf-L, neopterin, CXCL10, and protein in CSF.Nf-L was detected in all CSF samples  and positively correlated with markers of inflammation (CXCL10 (r = 0.733), neopterin (r = 0.499), cell count (r = 0.403), and protein levels (r = 0.693) in CSF; Nf-L in plasma and CSF has potential to be used as a biomarker of disease activity in HAM. Neuronal damage seems to be more intense early in disease but persists long term. Wheelchair-dependent patients have ongoing neuroinflammation. HAM pathogenesis is usually characterized by an initial inflammatory phase, followed by atrophy and neurodegeneration.2 The clinical course, although diverse, from mildly impaired mobility after decades to wheelchair dependency in weeks, greatly affects the patient's autonomy and quality of life.3 Some asymptomatic individuals also have discreet neurologic signs suggesting limited CNS damage.4 Cognitive dysfunction and encephalitis have also been reported with HTLV-1, indicating that the damage is not restricted to the spinal cord.5 Recently, a classification of disease severity was proposed based on neopterin and CXCL10 concentrations in CSF which correlated with very slow, slow, or rapid progression.6 CXCL10 has been associated with HAM pathogenesis via a positive feedback loop involving interferon-induced astrocyte activation, upregulation of CXCL10, and recruitment of inflammatory cells to the spinal cord. However, markers of neuronal damage have not been comprehensively studied in HAM.2 The identification of markers of minor or ongoing neurologic damage is important to identify incipient lesions to guide early therapeutic interventions and to better stratify patients in future therapeutic trials. Neurofilaments are structural proteins that are only expressed in neurons. Neurofilament light (Nf-L) is being increasingly used as a marker of neuronal damage.7 In this study, markers of inflammation and neuronal damage were measured in CSF and plasma to verify the potential of Nf-L as a biomarker for HAM.Human T-cell lymphotropic virus type 1 (HTLV-1) infects for life at least 5–10 million individuals.Stored paired ethylenediamine tetraacetic acid plasma and CSF (n = 83) obtained from 49 patients attending the National Centre for Human Retrovirology, St. Mary's Hospital, London, were included in the study: 41 patients with HAM; 3 HTLV-1 asymptomatic carriers; 1 patient with small fiber neuropathy; 3 coinfected with HIV-1, of which 2 had HAM; and 1 HTLV-2 asymptomatic carrier. Nineteen patients with HAM had samples at 2–6 different time points, mean follow-up 5.2 years (range 0.5–11 years). Clinical data consisting of age, sex, duration of symptoms, and disease severity, as assessed by walking aid usage, were also analyzed.8 Routine CSF analysis included total protein and cell counts. All CSF markers were measured by ELISA, according to manufacturers' instructions. CSF samples were assayed undiluted for neopterin , whereas 1:2 and 1:10 dilutions were used for Nf-L and CXCL10, respectively (Abcam and Uman Diagnostics). Nf-L was quantified in undiluted plasma by ELISA (n = 45) and by the highly sensitive, single molecule array  assay (n = 23). All samples were assayed in duplicate, and the mean value was reported.HTLV-1 proviral load was determined by real-time PCR.The samples had been donated by patients following written informed consent to the Communicable Diseases Research Tissue Bank National Research Ethics Service reference 15/SC/0089 or were residual samples after routine clinical investigations were complete with linked-anonymized clinical data provided by the clinical service.Deidentified data will be shared on request from a qualified investigator.links.lww.com/NXI/A605. Neopterin  was detected in every CSF sample. CXCL10  was not detected in 2 asymptomatic carriers and in 1 patient with HAM, who was still walking unaided 3 years after disease onset with no deterioration in 10-m time walk.Demographics, clinical characteristics, and routine laboratory measures are summarized in the supplementary eTable, Nf-L was detected in all CSF samples (n = 73) . According to the manufacturer's reference range and accounting for patient's age, all 4 (100%) asymptomatic carriers had normal Nf-L concentrations, whereas 37% of CSF samples from patients with HAM were high. Median plasma Nf-L was 10.5 ranging from 4.3 to 154.5 pg/mL.p = 0.006), although discrepant results (higher concentrations of Nf-L in plasma when measured by ELISA than in CSF) were observed in 8.8% of patients , with the exception of CSF cell count with CXCL10 . Nf-L inpatients .In patients with HAM, markers of inflammation (CXCL10 and neopterin) and neuronal damage (Nf-L) increased according to the degree of walking impairment being highest in wheelchair-dependent patients . There w9 However, persistent inflammation and neuronal damage was observed in most patients. With up to 11 years of follow-up between samples, this study shows that inflammatory markers remain elevated many years after disease onset. This evidence of ongoing CNS inflammation was also seen in wheelchair-dependent patients in whom clinical evidence of progression is difficult to detect. This suggests that even late in the disease course, some may still benefit from therapies that target inflammation, such as corticosteroids and steroid-sparing agents.9 Clinical studies would need long follow-up to prove benefit. Nf-L has the potential to evaluate continuing neurologic damage in patients with HAM and as a screening tool for therapeutic benefit. It can also be helpful as a tool for the stratification of patients into more homogenous groups for future clinical trials, as strongly recommended in the guideline for HAM treatment.9 Treatment for HAM is still limited, and clinical trials are urgently needed.Neuronal damage in patients with HAM, evaluated by quantifying Nf-L in CSF and plasma, appears to be more intense early in the disease. This highlights the importance of early diagnosis and prompt intervention, which tends to have better results.Recently, more sensitive techniques, such as SIMOA, have allowed Nf-L quantification in plasma samples, where the concentration is lower than CSF. Plasma sampling would make sequential sampling amenable both for patients with HAM and the follow-up of asymptomatic individuals. As Nf-L in plasma in this cohort of patients with HAM correlates not only with the levels of Nf-L in CSF but also with the CSF concentrations of inflammatory markers, it may be an alternative to monitor disease activity in patients with HTLV and to detect early, subclinical neuronal damage in those considered asymptomatic carriers of HTLV-1 infection. This would support therapeutic intervention even before clinical signs are evident, preventing or delaying HAM incidence and progression.10 Another limitation is the reference range for Nf-L. Although we used those proposed by the manufacturer, this is based on a limited number of samples and may be not truly representative.The present study has some limitations. Some patients were taking potentially disease-modifying therapy. In this center, the treatment is offered in a case-by-case manner, and those with more severe clinical presentation are those who are usually under treatment. No difference was observed between samples according to treatment status (data not shown). However, studies of the impact of treatment on Nf-L levels are important. Previous studies showed that inflammatory markers decrease with treatment and that this is associated with clinical outcome.In conclusion, neuroinflammation and neuronal damage, while being most intense early in disease, persists and is highest in those who have become wheelchair dependent. Nf-L has potential to be a useful biomarker in patients with HAM.


Primary central nervous system lymphoma (PCNSL) is an uncommon disease accounting for around 3% of primary CNS tumors. PCNSL exhibits aggressive clinical behavior and has an overall poor prognosis. The clinical presentation is variable, and there are no specific symptoms. Despite progress in radiographic neuroimaging, stereotactic brain biopsy remains obligatory for definitive diagnosis. Advanced standard diagnostics, including CSF cytology and flow cytometry, have limited sensitivity. Accordingly, there is an urgent need to improve the diagnostic tools for PCNSL, including novel non-invasive procedures. The aim of this review is to present and discuss modern methods that have the potential to contribute standard clinical diagnostics within the next few years.Primary central nervous system lymphoma is a rare but highly aggressive form of non-Hodgkin lymphoma that remains confined to the CNS neuroaxis. The diagnosis of PCNSL requires a high level of suspicion as clinical presentation varies depending on the involved CNS areas. Neurological symptoms and MRI findings may mimic gliomas, demyelinating lesions, or infectious and granulomatous diseases. Almost all PCNSL patients undergo invasive surgical procedures for definite diagnosis. Stereotactic biopsy is still the gold standard in achieving a diagnostic accuracy of 73–97%. Both the potential procedural morbidity and mortality, as well as the time to definite histopathologic diagnosis resulting in delays of treatment initiation, have to be considered. On the contrary, minimally invasive procedures, such as MRI, CSF cytology, and flow cytometry, still have limited value due to inferior specificity and sensitivity. Hence, novel diagnostic approaches, including mutation analyses (MYD88) in circulating tumor DNA (ctDNA) and the determination of microRNAs  as well as cytokine levels (IL10 and IL6) in blood, cerebrospinal fluid (CSF), and vitreous fluid (VRF), move into the focus of investigation to facilitate the diagnosis of PCNSL. In this review, we outline the most promising approaches that are currently under clinical consideration. Primary central nervous system lymphoma (PCNSL) is a rare disease accounting for around 4% of primary central nervous system (CNS) tumors in immunocompetent patients . PCNSL cUnlike other primary brain tumors, PCNSL responds favorably to chemotherapy and radiation. However, survival is usually worse as compared to systemic non-CNS lymphomas. Moreover, the prognosis of some patients, such as the elderly or patients with relapsed or refractory diseases, remains particularly poor.Various pathogenetic mechanisms in PCNSL have been described, including dysregulations in signaling pathways of NF-kB, JAK/STAT, Toll-like receptors, and B-cell receptors. Frequently, mutations in specific genes, including MYD88 (35–80%), PIM1 (69%), TBL1XR1 24%), TRDM1 (24%), BTG2 (29%), and PRDM1 (24%), contribute to disease pathogenesis [%, TRDM1 The clinical presentation of PCNSL is diverse, and the disease course is commonly subacute, depending on the involved CNS location. Frequent symptoms of PCNSL include cognitive dysfunction, personality changes, psychomotor slowing, and disorientation. Raised intracranial pressure, headaches, and focal symptoms occur in approximately 50% of cases. Brainstem and cerebellar signs, cranial nerve dysfunction, and seizures are observed less frequently [Patients who develop neurologic symptoms and deficits should urgently undergo diagnostic brain imaging. Magnetic resonance imaging (MRI) is the imaging modality of choice. Here, PCNSLs usually appear as solitary lesions (60–70%) or, less often, as multifocal diseases . LymphomDespite substantial improvements in radiographic techniques, neuroimaging patterns are suggestive but not diagnostic of PCNSL. Hence, definitive diagnosis must still be accomplished by stereotactic brain biopsy, including histopathology and immunohistochemical staining.Stereotactic biopsy remains challenging and traumatic, with a reported failure rate of up to 35% . FurtherAnother potential obstacle in the diagnostic process of lymphoma is the use of corticosteroids. Frequently, steroids are administered to control symptoms before a definite pathological diagnosis has been accomplished. Indeed, corticosteroids prevent definite  diagnosis due to rapid apoptosis of lymphoma cells .Analysis of CSF is an obligatory part of the standard diagnostic approach, unless lumbar puncture is contraindicated, e.g., due to abnormal intracranial pressure or impaired CSF kinetics due to cerebral herniation and space occupying lesions with mass effect in the large posterior fossa, Arnold-Chiari malformation, or a high risk of bleeding. Indeed, cytopathologic analysis of the CSF is considered the gold standard for the diagnosis of leptomeningeal malignant disease , althougAccordingly, there is an unmet need to further develop advanced diagnostic tests to facilitate the diagnostic process. Although many studies addressing non-invasive diagnostics of PCNSL have been conducted in recent years, none of the new methods are thus far established in everyday clinical practice.In this review, we intend to discuss the most promising non-invasive assays in cerebrospinal fluid (CSF) and in peripheral blood for the diagnosis of PCNSL with a clinical focus.Leptomeningeal seeding frequently occurs in PCNSL and has been demonstrated in as many as 80% of patients, as reported by Onda et al. in post-mortem histopathology . SensitiCanovi et al. compared the diagnostic accuracy of flow cytometry and cytomorphology for leptomeningeal involvement by lymphoid malignancies in a study that included the results of 27 trials . UnfortuIt should be emphasized that CSF cells are fragile and must be processed within a short period following a lumbar tap. Alternatively, CSF cells can be preserved in cell stabilizing reagents.The potential diagnostic utilization of kappa and lambda free immunoglobulin light chain (FLC) concentrations and ratios in the CSF has been examined in two studies ,16 Tabl. HildebrInterleukin-10 (IL-10) and its receptors are overexpressed in PCNSL and function as strong immunosuppressive and anti-inflammatory cytokines. They play different roles in the development and progression of lymphoma and inhibit apoptosis . On the Sasayama et al. reported that CSF concentrations of IL-10 and IL-6 are significantly increased in PCNSLs as compared to other brain tumors . SettingOn the other hand, Ungureanu et al. reported lower CSF levels of IL-6 in PCNSL patients compared with CNS inflammatory lesions. The levels of IL-10 were significantly higher in the same group of PCNSL patients .The most striking data were reported by Song et al.: CSF samples collected from 22 PCNSL patients were analyzed, and IL-10 at a cut-off of 8.2 pg/mL resulted in a sensitivity and specificity of 95.5% and 96.1%, respectively. Applying a CSF IL-10/IL-6 ratio with a cut-off value of 0.72 increased the sensitivity to 95.5% and the specificity to 100.0% [In addition, Costopoulos et al. were able to differentiate patients with B-cell lymphoproliferative disorders from DLBCL measuring IL-10 and IL-10/IL6 ratios in CSF .Even if the results of single studies appear promising, it must be noted that the results are hardly comparable due to various cut-off values . Due to CXCL13 is a chemokine that plays an essential role in the homing of B-cells . RubenstIn another study, the combination of CSF CXCL-13 and CSF IL-10 together with impaired diffusion coefficients in cranial MRIs was examined. The study population comprised 38 PCNSL and 5 SCNSL patients. In summary, the authors described a sensitivity of 76.7% and a specificity of 90.9% for CXCL-13 at a cut-off value of >103 pg/mL, as compared to 44 patients in the control group suffering from different brain tumors or tumefactive demyelinating lesions .It is undisputed that further studies with uniform cut-off values are necessary to pave the way for clinical usage of CXCL-13 .The term “liquid biopsy” refers to the analysis of tumor-derived DNA from blood specimens to avoid an invasive tissue biopsy. Cell-free DNA fragments (cfDNA) are shed into the bloodstream from cells undergoing apoptosis and necrosis or are transferred into the blood via direct secretion of exosomes. CfDNA circulates in plasma at a low concentration.To date, numerous molecular markers and genetic variants have been identified using peripheral blood samples in patients with primary brain tumors. The mutant allele frequency (MAF) should exceed 5% to reliably enable the detection of markers. Thus, the blood–brain barrier may hinder the detection of the required amount of cfDNA in plasma . HoweverConcentrations of cfDNA vary between different lymphoma subtypes. The levels of cfDNA are higher in aggressive lymphomas compared to indolent lymphomas. Furthermore, tumor burden also affects cfDNA concentrations, which are consequently higher in advanced-stage diseases than in limited-stage diseases .Recently, nucleic acid analysis by next-generation sequencing (NGS) has unraveled several genomic alterations in PCNSL . AlteratMYD88 mutations are detectable in 58% to 86% of PCNSL cases ,39,40. TInterestingly, the MYD88 L265P variant has been reported to be associated with poor prognosis, especially in elderly patients .Furthermore, detection of MYD88 L265P in cellular DNA from vitreous aspirates has been reported to improve the diagnosis of PCNSL. Bonzheim et al. have described the detection of MYD88 L265P in the majority (69%) of clinically, histologically, and molecularly confirmed vitreoretinal lymphoma. In addition, MYD88 L265P displays 100% specificity for the diagnosis of vitreoretinal lymphoma . TherefoOverall, the Achilles heel for the detection of specific mutations in blood, CSF, and the vitreous is low sensitivity . The truCurrently, reverse transcription quantitative PCR (RT-qPCR) and panel next generation sequencing (NGS) are the techniques most often applied for the detection of MYD88 mutations , althougThus far, clinical or histological parameters in PCNSL patients that impact cfDNA shedding in plasma or CSF still remain unexplained. Overall, tumor volume has been demonstrated to contribute to the identification of tumor-derived alterations in blood cfDNA for nodal DLBCL . Higher An important question in liquid biopsy of CNS tumors is whether plasma or CSF sampling is better for the detection of specific mutations in cfDNA of PCNSL. De Mattos-Arruda et al. demonstrated that cfDNA derived from the CNS was present at higher levels in CSF as compared to plasma in patients with malignant tumors limited to the CNS . A possible explanation is that the cerebrospinal fluid is in intimate contact with tumor cells in CNS malignancies. Moreover, despite the disturbed blood–brain barrier, the proportion of cfDNA in the blood is too low to be detected.Testing for IgH gene rearrangements by PCR is an interesting diagnostic method of monoclonal B-lymphoma cell detection in CNS lymphoma. Sensitivities between 11% and 54% have been reported . This PCmicroRNAs (miRNAs) are relatively small (18–24 nucleotides in length) non-coding RNAs that suppress gene expression post-transcriptionally by binding to target mRNA, triggering their degradation or translational downregulation. MiRNAs are involved in various biological processes, including cell proliferation, differentiation, metabolism, apoptosis, and tumorigenesis. Deregulated expression of miRNAs is commonly observed in human cancers. MiRNAs can also act as oncogenes or tumor suppressors. Therefore, expressions of individual miRNAs and miRNA signatures represent potent diagnostic and prognostic tools. Several miRNAs  were illustrated to have a significant impact in the pathogenesis of DLBCL . It has n = 39) of PCNSL patients [In our own study, miRNA expression levels were determined in CSF samples collected from patients with PCNSL as compared to other neurologic disorders using TaqMan quantitative real-time PCR assays. Among six previously described candidate miRNAs , the concentrations of miR-21, miR-19b, and miR-92a were significantly increased in the CSF of PCNSL patients compared with those from patients with other neurologic disorders. Accordingly, a diagnostic tree was suggested, starting with testing for miR-21 elevation, followed by testing for miR-19 and miR-92a increases. The diagnostic tree of these three CSF miRNAs represented a reliable diagnostic biomarker for PCNSL, with a diagnostic accuracy including 95.7% sensitivity and 96.7% specificity . These dpatients . Furtherpatients .Moreover, CSF concentrations of the above-mentioned miRNAs were significantly correlated with PCNSL disease status during therapy and/or disease follow-up, demonstrating their capability as biomarkers for treatment monitoring and follow-up . In a meThe role of microRNA determination in peripheral blood for the diagnosis of CNS lymphoma remains questionable. In our own studies, insignificant differences in serum microRNAs between PCNSL patients and control patients were observed . On the Previously, we analyzed the combination of CSF marker miR-21 with small nuclear RNA fragments of RNU2-1f in CSF . For difAnother study reported increased serum concentrations of miR-222 as a potential biomarker for early diagnosis of DLBCL and PCNSL in HIV-infected individuals .It is possible that combinations of CSF- and serum-based miRNAs with currently available and promising biomarkers, such as MYD88 and CSF interleukin-10, could further improve diagnostic sensitivity and accuracy .Combined “classical” CSF analysis, consisting of cytopathological analyses and immunophenotyping by flow cytometry, improves the diagnostic accuracy for PCNSL. However, the role of CSF markers indicating B-cell proliferation, including MYD88 mutational and microRNAs profiles, is increasing. These new biomarkers have the potential to improve the differential diagnosis of PCNSL. Nevertheless, validation and standardization as a prerequisite for routine clinical application are still pending.


Leptomeningeal metastasis (LM) is a devastating complication of cancer with variable clinical presentation and limited benefit from existing treatment options. In this review, we discuss advances in LM diagnostics and therapeutics with the potential to reverse this grim course. Emerging cerebrospinal fluid circulating tumor cell and cell-free tumor DNA analysis technologies will improve diagnosis of LM, while providing crucial genetic information, capturing tumor heterogeneity, and quantifying disease burden. Circulating tumor cells and cell-free tumor DNA have utility as biomarkers to track disease progression and treatment response. Treatment options for LM include ventriculoperitoneal shunting for symptomatic relief, radiation therapy including whole-brain radiation and focal radiation for bulky leptomeningeal involvement, and systemic and intrathecal medical therapies, including targeted and immunotherapies based on tumor mutational profiling. While existing treatments for LM have limited efficacy, recent advances in liquid biopsy together with increasing availability of targeted treatments will lead to rational multimodal individualized treatments and improved patient outcomes. The pachymeninges are served by the systemic circulation and lie outside the blood-brain and blood-cerebrospinal fluid (CSF) barrier systems. The leptomeninges include the multilayered arachnoid membranes and pia mater and contain the circulating CSF.1 The leptomeninges reside behind the blood-CSF-barrier and may host a number of neurologic conditions including infections, inflammatory conditions as well as cancer.2 Spread of cancer cells into pia mater and the arachnoid membrane is referred to as leptomeningeal metastasis (LM).The tissues surrounding the brain and the spinal cord, or meninges, are comprised of the outer pachymeninges and the inner leptomeninges.3 Impaired CSF resorption due to LM can cause obstructive hydrocephalus and symptoms of increased intracranial pressure. Spine involvement from LM may lead to pain, weakness, dysautonomia, and genitourinary dysfunction.3 Despite debilitating clinical symptoms, establishing the diagnosis can be challenging due to significant limitations in available radiographic and laboratory studies.4Reflecting the diffuse nature of the disease location, LM is associated with a myriad of clinical manifestations that lead to substantial morbidity. CNS involvement from LM can result in encephalopathy, headache, seizures, and multiple cranial neuropathies with associated diplopia, dysphagia, and dysarthria.5-8 Some variability in prognosis based on tumor type has been reported with LM secondary to lung cancer associated with poorer prognosis compared to breast cancer and melanoma.4-7 Tumor subtype can influence the prognosis as well with HER2+ and hormone receptor-positive breast cancer associated with better prognosis compared to hormone negative tumors8 and prolonged survival reported in EGFR mutant lung cancer treated with EGFR tyrosine kinase inhibitors compared to LM from other non-small cell lung cancers (NSCLCs).9 This bleak outcome is a direct result of major roadblocks in the study of LM, which impede the development of effective treatments and include: 1. Diagnostic challenge; 2. Inability to quantitate disease burden; 3. Genetic heterogeneity. However, many of these barriers will soon be overcome. Herein we review these emerging diagnostic tools for better detection, quantification, and prognostication of LM as well as multiple treatment modalities that portend improvements in management of this devastating complication of cancer.LM carries a grim prognosis. Survival following diagnosis of LM from solid organ tumors such as lung cancer and breast cancer averages less than three to six months despite treatments including supportive care, radiation therapy, and intrathecal chemotherapy.10 LM within the spinal cord can be identified as enhancement along the spinal cord or clumping enhancement of the cauda equine.10 However, MRI imaging has significant limitations. Radiographic findings may not correlate with symptoms, may be difficult to distinguish pachymeningeal from leptomeningeal disease, and a normal craniospinal MRI does not exclude a diagnosis of LM.11 In addition, leptomeningeal enhancement noted on MRI is nonspecific and carries a broad differential including inflammatory conditions such as neurosarcoidosis and infections such as human T-lymphotropic virus.2Classically, LM is diagnosed on the basis of magnetic resonance imaging (MRI) and CSF cytology. Cranial LM involvement can be identified on MRI as contrast enhancement along cranial nerves and the leptomeninges, particularly in the cerebellar folia .10 LM wi4 CSF cytology allows for direct visualization and identification of neoplastic cells, representing an important tool for diagnosing LM. However, sensitivity from a single CSF sample is low.10 Results of CSF cytology can be inconclusive, with occasional isolation of “atypical” or “suspicious” cells that are not definitively neoplastic.11 Multiple CSF samples may be required to improve yield with sensitivity increasing from 60% on first lumbar puncture to 85% and 90% on second and third CSF cytology analyses respectively.11CSF profile is often abnormal in LM with lymphocytic pleocytosis, elevated protein, and decreased glucose representing the most frequently observed, but nonspecific findings.False-negative radiographic imaging and cytology analysis can lead to additional invasive testing such as repeated CSF sampling or leptomeningeal biopsy while delaying diagnosis and treatment. In addition, neither neuroaxis imaging nor CSF cytology can provide information about tumor molecular genetics. Knowledge of the molecular makeup of malignant cells in the leptomeninges is indispensable in the era of emerging targeted treatments. Emerging technologies utilizing analysis of CSF circulating tumor cells (CTCs) and cell-free tumor DNA (ctDNA) provide an opportunity for tumor analysis via liquid biopsies .12 The system for peripheral blood has been adapted to analyze CSF and detect LM from breast cancer as well as lung cancer.12–14 Reported sensitivities of EpCAM-based LM detection are between 76–100%, compared to 44–67% from cytology analysis on the first lumbar puncture.15 Analysis can be performed using 3 mL of CSF with ≥1 CSF-CTC/mL suggested as the optimal cutoff for diagnosis of LM.16 Though these small studies focused primarily on lung and breast tumors, the high reported sensitivities suggest that CTC enumeration may represent a reliable tool for detection of LM; further validation is needed and this methodology can be prone to sampling error similar to conventional cytology. EpCAM is not usually expressed by nonepithelial malignancies. In the case of melanoma, High-Molecular Weight-Melanoma-Associated Antigen/Melanoma-associated Chondroitin Sulfate Proteoglycan (HMW-MAA/MCSP) has been identified and can be used for CTC isolation.17 Mesenchymal tumors and tumors that have undergone epithelial to mesenchymal transition are likewise not detected by EpCAM-based assays.17 Further modifications to existing technology for isolation of CTCs from other tumor types will be needed. Other platforms may assist in detection of nonepithelial metastatic cells as well as cells that have undergone epithelial to mesenchymal transition.18Commercially available assays are available for the detection of CTCs in CSF. Originally designed for identification of CTCs in peripheral blood, one commercial assay is based on the expression of epithelial cell adhesion molecule (EpCAM), a transmembrane glycoprotein detected in cells of epithelial origin.15 Antibodies against other tumor or organ-specific markers may also be employed in CSF analysis.19 One advantage of flow cytometry is that it can be performed using standard flow cytometry equipment already available in many clinical laboratories. However, standardization of detection methodology is needed to ensure results are reproducible and reliable across institutions. Moreover, while flow cytometry represents a standard diagnostic tool for the detection of LM in hematological malignancies, this technology has been only minimally employed in solid tumor LM.Flow Cytometry (sometimes described as “immunoflowcytometry”) may also be used to identify CTCs in CSF. In flow cytometry, CTCs are identified and quantified using fluorescently labeled antibodies against proteins such as EpCAM or HMW-MAA/MCSP.20 Label-free methods based on physical characteristics of CTCs for isolation of more heterogeneous CTC samples and label-based methods leveraging affinity between CTCs and ligands are under investigation.20 Micropores, micropillar arrays, and optical methods are among the techniques that have been used for CTC isolation from small fluid samples based on cell physical properties such as size, density, and dielectric properties.20 Though these technologies are not yet widely available for CSF analysis, single cells from CSF of patients with NSCLC-associated LM have been reported.21 With further advances in isolation methods, incorporation of CSF CTC detection into the standard workup for LM may improve diagnostic yield, leading to earlier detection without the need for multiple conventional CSF cytology analyses and earlier initiation of treatment.Given the current limitations of both commercial EpCAM-based assays and flow cytometry methodologies, microfluidics is emerging as an alternative means of CTC isolation, with the goal of increasing sensitivity and enhancing cell recovery with potential for high-throughput processing and automation.22 The study also reported increased CTCs in three patients approximately one month prior to clinical signs of progression.22 These early findings suggest CTCs could provide quantitative measures of response, recurrence, and progression. CSF CTCs may also have a prognostic significance: increased serum CTCs portend a worse prognosis in solid tumors23; changes in the number of CSF CTCs on serial sampling may similarly predict prognosis, providing essential information for risk stratification, and treatment planning.Beyond diagnosis, CSF CTC analysis may potentially also alter prognostication and treatment in LM. Unlike traditional CSF cytology, CSF CTC analysis provides a quantitative measure of tumor cells. As such, the CSF CTC enumeration holds the potential to serve as a biomarker. In patients with LM secondary to breast cancer receiving intrathecal trastuzumab, a decreased number of CTCs was reported in those responding to treatment.23–25 In a study of breast cancer patients with LM, genomic analysis of CSF CTCs identified alterations commonly found in primary breast tumors, confirming the breast tumor origin of the isolated cells.26 When CSF CTC DNA was compared to archival primary tumor DNA, clonal divergence was identified with alterations such as 8q24 gain more frequently observed in CSF CTCs compared to archival primary tumor tissue.26 The 8q24 gain includes the MYC locus, which represents a potential opportunity for future targeted treatment.26 In another study of eight patients with breast cancer and LM, the breast origin of isolated CTCs and evidence of clonal divergence were again noted.24 Drug sensitivity testing was performed on CSF CTCs with CDK4/6 inhibitor palbociclib identified as the agent with greatest antitumor effect. Similar results were obtained from a study of non-small cell lung cancer (NSCLC) patients with LM, which showed a high degree of concordance between primary tumor DNA and CSF CTC DNA, but also identified common NSCLC treatment resistance mutations such as amplification of the MET proto-oncogene and erythroblastic oncogene B2 (ERBB2) mutation.25 In a study of two patients with breast cancer and three patients with NSCLC-associated LM, single-cell RNA sequencing from CSF CTCs identified that cancer cells, but not CSF macrophages expressed iron-binding protein lipocalin-2.27 The study suggested cancer cells could outcompete macrophages for iron by lipocalin-2 expression, representing an important pathway for tumor cell proliferation within the CSF microenvironment.27 In mouse models, iron chelation therapy suppressed cancer cell growth, representing a potential treatment target.27Finally, CTC analysis allows for isolation of single tumor cells for DNA, RNA, and protein analysis.Together, these findings demonstrate proof-of-principle that CSF CTCs capture tumor heterogeneity present in LM. Study of CSF CTCs can identify mechanisms tumor cells utilize to survive and proliferate in CSF, lea. Comparison of primary tumor DNA to CSF CTC DNA will help elucidate mechanisms by which tumor cells adapt to and proliferate within the leptomeningeal space. Moreover, understanding the genomic profile of systemic as well as CSF tumor cells can assist with treatment planning, helping oncologists select agents with the greatest likelihood of success. CSF CTC analysis may also help identify resistance mutations, directing selection of further treatments and informing prognosis.28 Plasma ctDNA can be used to detect actionable mutations and resistance mechanisms that can aid in treatment planning.28 In a similar fashion, CSF ctDNA can provide detection of clinically relevant mutations from metastatic brain tumors as well as primary brain tumors.29An additional emerging technology, cell-free tumor DNA (ctDNA) analysis, may aid in characterization of tumor heterogeneity in LM. DNA is released from neoplastic cells as well as healthy cells into the bloodstream, where it can be isolated and studied.31: In twenty-eight patients with LM secondary to NSCLC harboring epidermal growth factor receptor (EGFR) mutations, CSF ctDNA harbored unique mutations and copy number variations in CSF.30 As an example, MET copy number gain was most frequently identified in CSF ctDNA analysis of this patient population, followed by ERBB2, KRAS, ALK, and MYC.30 Loss of heterozygosity of TP53 was much more frequent  in CSF ctDNA compared to plasma ctDNA .30 EGFR T790M, a resistance mutation against tyrosine kinase inhibitors (TKIs) targeting EGFR-mutant tumors, was identified in CSF ctDNA of seven patients experiencing progression on TKI.30 Similarly, in a larger study of seventy-two patients with LM secondary to NSCLC, CSF more reliably identified NCSLC driver mutations when compared with plasma.32 EGFR mutations, ALK fusions, and ERBB2 amplifications were all more frequently observed in CSF compared to plasma.32 However, EGFR T790M was more frequently detected in plasma  compared to CSF .32 TP53 loss of heterozygosity was much more frequent in CSF ctDNA  compared to plasma .32 In a series of 11 patients with BRAF-driven malignancies, CSF ctDNA detected BRAF mutations in 3/3 patients with radiographic evidence of LM and 2/5 patients with brain parenchymal metastases.31 Conventional cytology was negative for tumor cells in one patient with radiographic evidence of LM while CSF ctDNA detected tumor-derived DNA.31Early data employing for CSF ctDNA sequencing demonstrates the utility of this analysis: cancer residing with the CSF may harbor mutations distinct from those of the primary tumor33 Though a small series, further validation may demonstrate that ctDNA may provide diagnosis in the setting of negative cytology and imaging findings or identify individuals at risk for developing LM. Further, ctDNA may be used to assess treatment response or disease progression in the CSF.31 Whereas a traditional biopsy captures tumor makeup at a single timepoint, liquid biopsies allow longitudinal measurement of tumor characteristics.28 This may allow for the detection of escape mutations prior to accumulation of new neurologic deficits. Taken together, these findings illustrate the ability of CSF ctDNA analysis to identify driver mutations, detect presence of LM, capture and describe clonal divergence among populations of tumor cells, and potentially guide treatment planning by identifying resistance mutations or novel pathways for targeting. Additional advances in DNA extraction and analysis technology will likely further improve the yield and utility of ctDNA analysis.34 Prior to widespread clinical implementation, further validation of both CSF CTC and CSF ctDNA technologies are essential.35Beyond detection of tumor mutations, CSF ctDNA may have utility in LM detection and monitoring: In a case series of two patients with lung cancer, CSF ctDNA analysis revealed mutations in a signaling pathway oncogene K-ras prior to radiographic and cytologic confirmation of LM.4 Due to the lack of large randomized controlled clinical trials, evidence-based treatment recommendations in LM are limited.4 In absence of prospectively validated criteria, assessment of treatment response can also be challenging. To address this issue, a Response Assessment in Neuro-Oncology (RANO) workgroup proposed criteria for LM response to treatment which combines neurologic examination, CSF analysis, and MRI findings.36 The original RANO proposal for response criteria provided a scorecard for radiographic assessment of LM with points assigned for presence of subarachnoid or ventricular nodules, leptomeningeal enhancement, and cranial nerve enhancement to characterize brain and spine involvement while noting parenchymal and epidural involvement.36 Due to discordant scoring noted upon review of MRIs from 22 patients with LM, a simplified scorecard noting the presence or absence of subarachnoid/ventricular nodules and leptomeningeal linear enhancement in the brain and the spine was proposed, but needs further validation.36 European Association of Neuro-Oncology (EANO) and European Society for Medical Oncology (ESMO) have jointly issued practice guidelines for diagnosis and treatment of LM.37 EANO-ESMO guidelines provide a treatment algorithm based on patient’s prognosis, presence of concurrent brain metastases, and state of extracranial disease.37Current clinical practice is dominated by the poor outcome of LM. The primary goals are therefore symptomatic management by surgical and/or radiation-based therapies followed by intrathecal and/or systemic chemotherapy .4 Due to39 Despite short overall survival, VPS placement is an effective palliative measure39 with peritoneal carcinomatosis an extremely rare complication.39Surgical resection of metastatic lesions is not within the standard treatment protocol of LM. Neurosurgical intervention can be needed, however through the management of obstructive hydrocephalus and increased intracranial pressure. Treating hydrocephalus from LM can include high volume lumbar puncture for symptomatic relief and placement of ventriculoperitoneal shunt (VPS) systems if needed for longer-term relief.40-43 WBRT provides symptomatic relief and improves neurologic function, though it does not confer a survival benefit, particularly in the setting of breast and lung cancer.45 Expanding the treatment field further, (photon) craniospinal radiation is associated with significant myelosuppression, severely limiting its utility in patients receiving chemotherapy.40 To build on the palliative benefits of RT and limit toxicities, several investigators have turned to proton beam RT. Though prospective data and direct comparisons of proton versus photon radiation are lacking, use of proton RT may lead to lower radiation exposure decrease toxicities such as myelosuppression.46Radiation therapy to symptomatic sites is standard palliative care for LM. Multiple RT modalities are available, including craniospinal RT, whole-brain radiation therapy (WBRT), or focal radiation  to areas of bulky disease.4 This approach is reserved for patients with nonbulky disease and normal CSF flow dynamics. In retrospective studies, image-guided placement of intraventricular catheters has been shown to be accurate and safe,47 providing homogeneous distribution within the subarachnoid space.48 Retrospectively, patients receiving IT chemotherapy via intraventricular catheter demonstrated better overall survival than those receiving IT therapy to the lumbar cistern.49Chemotherapy may be delivered directly into the leptomeningeal space directly into the lumbar cistern via lumbar puncture or the intraventricular space using a surgically-placed catheter (Ommaya).48 Standard preparations of IT methotrexate, cytarabine, and thiotepa are all administered twice a week for four weeks, followed by four weeks of weekly infusions with once a month maintenance thereafter.48 Efficacy of these three single agents is similar.51 Very limited data is available for combination IT chemotherapy: In a study of fifty-five patients with LM, median survival was longer in patients treated with cytarabine and methotrexate combination therapy versus methotrexate alone, median survival was longer in the combination therapy group, but this has not been validated in larger prospective studies.52 Given singly, toxicities from IT methotrexate, thiotepa, and cytarabine administration are similar and include headache, nausea, vomiting, and fever, which are common sequelae of chemical meningitis and arachnoiditis54 as well as hemorrhage and infectious meningitis.55 IT methotrexate in particular, is associated with delayed leukoencephalopathy.55 The incidence chemical meningitis or arachnoiditis related to IT chemotherapy remains unknown. However, in one study, significant adverse events including paresthesias and paralysis were reported in 8.3% of patients undergoing IT chemotherapy whereas minor events such as headache, back pain, or nausea occurred in 26.6% with strong correlation between total number of IT treatments received and likelihood of at least one adverse event.53 Attempts to develop IT formulations from other untargeted IV agents such as topotecan or etoposide have been less effective.57Currently, methotrexate, cytarabine, and thiotepa are the most common agents administered intrathecally for LM secondary to solid tumors. However, optimal dosing and duration of treatment remains unclear and direct comparisons in clinical trials are lacking.58 Intrathecal checkpoint inhibitor administration has been attempted in LM due to melanoma59 and is the subject of clinical trial NCT03025256.60 The monoclonal antibody against Her2/neu, trastuzumab, has poor CNS penetration when given systemically, but given IT, trastuzumab has been well-tolerated and may have a role in management of Her2+ breast cancer LM.62 Similar repurposing of targeted treatment agents for melanoma and lung cancer may yield effective treatments against LM from solid organ tumors.Select systemic antibodies may be delivered IT. Rituximab, a monoclonal antibody to CD20, delivered IT was associated with 60–76% response in patients LM due to primary or secondary central nervous system (CNS) lymphoma.64 However, despite the rationality of this treatment approach, randomized trials are lacking; conventional systemic agents have limited efficacy in LM to date.63 High-dose IV methotrexate achieves cytotoxic concentrations within CSF, has been associated with modest survival benefit, and is among the most commonly used systemic agents for LM,64 particularly for LM due to breast cancer. Capecitabine has been employed in several case reports demonstrating efficacy in LM secondary to breast cancer65 or esophageal cancer.66 Other agents that have been considered for systemic chemotherapy of LM include cytarabine and temozolomide. High-dose IV cytarabine can achieve cytotoxic concentrations within CSF, but efficacy of this treatment in patients with LM from solid organ tumors has not been demonstrated.67 Commonly used in management of primary brain tumors, the alkylating agent temozolomide is not effective against LM as a single agent.68Systemic chemotherapy is suitable for patients with bulky disease or impaired CSF flow. Moreover, this approach eliminates need for intraventricular catheter placement or repeated lumbar punctures.69 Primary endpoint of survival at three months was achieved with 12 of 20 patients alive after three months of enrollment, though median overall survival was 3.6 months.69 Response to nivolumab treatment in a patient with LM secondary to NSCLC and another with LM secondary to renal cell carcinoma have also been reported.71 These preliminary findings suggest there may be a role for checkpoint inhibitor therapy in management of LM, particularly in patients who have not received immunotherapy as part of their treatment regimen at initial diagnosis.Immunotherapy with checkpoint inhibitors is under investigation for management of LM. In a single-arm phase II study, 17 patients with breast cancer, two with lung cancer, and one with ovarian cancer were treated with pembrolizumab.Overall, conventional cytotoxic chemotherapy has not demonstrated a prospectively validated clear sustained survival benefit in patients with LM. To date, no targeted chemotherapy has received Food and Drug Administration (FDA) approval for treatment of leptomeningeal disease. However, select targeted chemotherapies present novel and effective treatment strategies for LM and may be validated with further studies.72 and the MEK inhibitor trametinib.73 Combined BRAF and MEK inhibitor therapy in BRAF-driven LM malignancies may be effective in patients naïve to these agents. However, in practice, patients harboring LM from melanoma have typically already been treated with BRAF and MEK inhibitors.74In patients with LM from melanoma harboring BRAF V600E mutations, there are reports of LM response to BRAF inhibitors such as dabrafenib and vemurafenib76 However, resistance mutations invariably develop. Third-generation TKIs such as osimertinib and rocetilinib have been designed to overcome the most common resistance mutation EGFR T790M.78 Osimertinib penetrates the CNS and appears effective in treating LM in patients with EGFR T790M-mutated NSCLC.79 Similarly, in patients with NSCLC with ALK chromosomal arrangements, the small molecule TKI crizotinib has been an effective first-line treatment.80 Tumor resistance to crizotinib has been recognized, leading to development of additional ALK inhibitors.80 Of these newer agents, alectinib demonstrates some efficacy against LM,81 there is anecdotal evidence of similar efficacy of lorlatinib in LM.In patients with EGFR-mutated NSCLC, tyrosine kinase inhibitors such as erlotinib and gefitinib are demonstrably effective first-line therapeutics.82 and CSF VEGF levels are negatively correlated with LM survival.83 Addition of bevacizumab to existing regimens improves CNS response in LM: In breast cancer-associated LM, combination therapy with bevacizumab, etoposide, and cisplatin (BEEP therapy) demonstrated CNS response and improved overall survival.84 Similar results have been reported in small case series of addition of bevacizumab to erlotinib in EGFR-driven NSCLC LM.85 Together, these reports suggest addition of bevacizumab to existing chemotherapy regimens may improve CNS response in patients with LM.The vascular endothelial growth factor (VEGF) inhibitor bevacizumab also shows promise: High levels of VEGF are associated with LM diagnosisRecent advances in detection, quantification, and targeting of cancer cells within the spinal fluid have the potential to revolutionize the study and management of LM. Emerging CSF CTC and ctDNA technologies will improve diagnosis of LM and serve as biomarkers to assess disease progression and response to treatment, empowering intelligent clinical trial design and interpretation. CTC and ctDNA analysis will also provide a more detailed understanding of tumor genomics, paving the way to individualized targeted treatments focused on actionable mutations. In this way, liquid biopsies together with new targeted therapeutic approaches will enable formal clinical trials of LM enrolling carefully selected patients with quantitatively similar burden of disease, harboring biologically similar disease (as determined by driver mutation), receiving therapeutics targeting the driver mutation. This work will allow for establishment of treatment paradigms beyond our current regimens of symptomatic management with radiation therapy and ventriculoperitoneal shunting. With these tools in hand, we will make best use of intrathecal and systemic targeted and chemotherapeutic approaches to make clinically meaningful improvements for patients with LM.