Idiopathic intracranial hypertension (IIH) is a functionally limiting disorder secondary to increased intracranial pressures (ICPs) with a prevalence of one per 100,000 persons. It is estimated to cost >$400 million per year in productively. Symptoms classically consist of chronic headaches, papilledema, and visual loss. The pathophysiology is unknown but postulated to involve increased resistance to cerebrospinal fluid (CSF) absorption. Traditional treatments involve weight loss, acetazolamide, CSF diversion, or optic nerve fenestration. More recent technology has allowed exploration of venous sinus stenosis. Through venous sinus stenting (VSS), the ICPs and venous sinus pressures decrease. After treatment, >75% exhibit an improvement in headaches, ~50% improvement in tinnitus, and ~50 % improvement in ophthalmologic testing. Complications are rare but involve stent stenosis, femoral pseudoaneurysm, and hemorrhages. Future studies will look into controlled studies for VSS as well as expansion to other venous structures of the intracranial circulation. IntroductionIdiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri and benign intracranial hypertension, is a disorder characterized by persistently increased intracranial pressure (ICP) without an otherwise distinguishable pathology. It was first described by a German physician, Heinrich Quincke as Meningitis Serosain 1893, but not until the studies of a Davidoff and Dyke in 1936 was it characterized with a normal ventriculogram . Foley wThe classic triad includes chronic headaches, papilledema, and visual loss in the absence of other neurological signs, ventriculomegaly, and intracranial lesions on neuroimaging. The one exception is the occasional abducens nerve palsy noted in severe cases . In addiThe neurologic signs are papilledema, abducens nerve palsy, visual acuity worsening, and visual field loss. Papilledema is often considered a defining sign of IIH with an incidence of 95% . Though 2O from a lumbar puncture in a lateral decubitus position, 4) normal CSF composition, and 5) exclusion of a structural abnormality through advanced neuroimaging  [The modified Dandy criteria are the most widely accepted criteria Figure . It requography) . With the rapid advancement in imaging modalities, various signs on MRI have been associated with IIH and these assist in the establishment of IIH. These features include an empty sella turcica filled with CSF, deformed pituitary gland (occupying less than 50% of the fossa with an upper concavity), slit-like ventricles, tight sulcal and cisternal subarachnoid spaces, flattening of the posterior aspect of the optic globe with outward convexity of the globe in severe cases, distension of the optic nerve sheath with a width greater than 2 mm, vertical tortuosity of the optic nerve, and enhancement of the optic nerve. Agid et al. examined the sensitivity and specificity of these signs in 2006. The most sensitive signs were optic nerve sheath distention, pituitary compression, and globe flattening at 66.7%, 53.3%, and 43.3%, respectively, but the most specific were slit-like ventricles, optic nerve enhancement, and empty sella at 100%, 98.2%, and 94.6%, respectively . Though Differential diagnosisAs it is idiopathic, it is vital to exclude any other sources of neurological disease. There are various mimickers of IIH including structural, endocrine, nutritional, medicinal, and genetic disorders. Intracranial hypertension can be caused by any disorder that occludes CSF drainage , increases blood outflow , scars arachnoid granulations , or abnormal structures (mass lesion). Though not fully understood, steroid withdrawal, Addison's disease, and major endocrinological disorders have been linked to elevated ICPs .PathophysiologyThroughout the centuries, the pathogenesis of IIH has been elusive. Numerous etiologies have been proposed to attempt and describe the phenomenon of idiopathic elevated ICPs. A long list of risk factors has been collected through the decades: head injury, anemia, polycythemia vera, polycystic ovarian syndrome, synthetic growth hormones, vitamin A, family history, etc. +/K+ ATPase channel transporting Na+ to the CSF space with osmosis of H2O through aquaporin-1 channels. Carbonic anhydrase enzyme is vital in the Na+ passage through the production of protons and bicarbonate ions. Then, the CSF flows through the natural ventricular pathway and absorbed by the arachnoid granulations. In the arachnoid granulations, the CSF passes via flow dependent vacuoles determined by the pressure-gradient [In physiology, the production of CSF occurs in the choroid plexus lining the ventricles. CSF is produced through a Nagradient . The primary hypotheses in IIH are centered around an increased resistance to CSF absorption. MRI dynamic phase contrast showed decreased jugular flow in IIH along with altered spinal cord compliance. With the prospects of decreased venous flow, increased research focuses on the pathology of the venous outflow system. Increased ICPs is a known entity in venous sinus thromboses and dural arteriovenous fistulas and can cause some potentially life-threatening symptoms . The firThough there is controversy over whether venous stenosis is a primary cause of IIH or a secondary manifestation of the IIH, Buell et al. added valuable in vivo evidence to push the pendulum towards venous stenosis as a secondary manifestation of IIH. A lumbar puncture was done while measuring in vivo trans-stenosis maximal venous pressures (MVP); CSF drainage revealed a rapid resolution of the pressure gradient and venous stenosis. However, this was short-lived, and the patient eventually needed permanent venous stenting. The hemodynamics between the positive feedback of venous stenosis causing worsening IIH is evident; the increased pressure gradient causes lower venous sinus-CSF gradient, eventually resulting in decreased CSF resorption . This wiAlso, obesity and IIH have been closely linked. It has been proposed that increased abdominal girth increases intra-abdominal pressure, subsequently increasing the venous pressure of the spine and thus the ICP . Though Review of non-stenting treatmentsMedical Treatments2O to 17 cmH2O at three years in eight patients [The first-line treatments for IIH focus on lifestyle and pharmacological interventions. Initially, treatment focused on combating the association of IIH with obesity. As discussed in the pathophysiology section, a clear pathway has not been established but the association is undeniable. The incidence is significantly higher in obese patients and pre-stenotic MVPs in IIH patients, if used as a proxy for ICP, were found to have a direct relationship between BMI and MVP . Thus napatients . OverallThe pharmacological approach to IIH has been targeting the choroid plexus to decrease CSF. Acetazolamide has been the mainstay of pharmacological treatment since 1974; McCarthy and Reed showed decreased CSF flow with inhibition of choroid plexus carbonic anhydrase . In combSurgical InterventionsAlternatively, surgical interventions focus on decreasing ICPs through CSF diversion. In the least invasive approaches, serial lumbar punctures have been used for symptomatic control. However, though vital for diagnosis, the therapeutic utility of repeat symptomatic control has been controversial, increasing the risk of meningitis, arachnoiditis, intracranial hypotension, and tethering patients to repeated painful procedures. The procedure usually gives patients immediate but short-lived relief. CSF should be rapidly replaced in the subarachnoid spaces, but it did not; in the setting of improved venous stenosis with a high volume lumbar puncture, the prolonged relief could be from temporarily normalized CSF outflow, until the stenosis reoccurs ,23.Optic nerve sheath fenestration (ONSF) is another form of CSF diversion that aims to prevent the most serious morbidity, visual loss. A window or a series of small slits are made in the retrobulbar optic nerve sheath to drain CSF and decrease the optic nerve edema to prevent visual loss. Even if performed in a single eye, the contralateral eye has been shown to have an improvement in papilledema suggesting that the primary physiology might involve local decompression of the subarachnoid space. Though meant to primarily for the preservation of ophthalmologic function, it has shown to improved headache in ~50% patients . HoweverThe most common form of CSF diversion in IIH is CSF shunting through either a Ventriculoperitoneal shunt (VPS) or a Lumboperitoneal shunt (LPS), with 4,480 performed for IIH between 2005-2009. Historically, LPS has been the preferred choice of CSF shunting due to the technical difficulty of placing a VPS into slit-like ventricles. However, with the advent of image guidance, VPS is becoming the favored method of CSF shunting. VPS has shown to have fewer revisions, decreased shunt migration, shorter hospital stays, and the ability to place programmable shunt valves than an LPS. Also, it avoids the unique possibility of acquired Chiari malformations associated with LPS . Both meVenous sinus stentingKing et al. (1995) were the first to describe the venous stenosis through venography and manometry in IIH but Higgins et al. became the first to stent the venous sinus in 2002 on a female with medically refractory IIH -27. VenoPrior to further discussion of venous stenosis in the setting of IIH, it is important to detail the incidence of venous stenosis in the general population. Durst et al.reviewed a total of 355 normal CT angiographies without structural abnormalities to define normal venous sinus anatomy . StenosiTechnique2O) are offered a venous stent. Ultimately, venous manometry is a decision-making factor for VSS. Prior to stent placement, patients are given seven days of Aspirin 325 mg and Clopidogrel 75mg daily. Therapeutic P2Y12 (<208) and ARU (620-672) levels are needed to proceed or the patients are loaded with aspirin 325mg and clopidogrel 600mg. The stent placement procedure is done under general anesthesia for patient comfort. Venous access is attained and heparin bolus is given for a goal-activated clotting time of 250-300 seconds through the procedure. The access sheath system usually used is a triaxial construct of 12F, 9F, and 7F sheaths of length 80-90 cm. MVPs and trans-stenosis pressure gradient are reconfirmed prior to placement of the venous stent. The choice of a stent may vary based on individual patient anatomy. The stent is placed to span 10-mm pre-stenosis and post-stenosis. Post-stenting venograms are performed to look at the drainage patterns. The procedure is completed by closing the venous access by pressure. A CT scan is performed to rule out an intracranial hemorrhage. Patients will be on dual antiplatelet therapy for one month and aspirin 325 mg for three months. They will have a repeat angiogram at three months to evaluate for any complications [In venous sinus stenting (VSS), preoperative evaluation is paramount in the selection of the right patient population. All IIH patients should be assessed by neuro-ophthalmology for papilledema, visual acuity, optical coherence tomography, and visual field testing. MRI should be done with possible MR angiography and MR venography in appropriate circumstances. Elevated ICPs should be defined through either a high volume lumbar puncture or intracranial pressure monitor. The authors’ preferred method of treatment is to perform a cerebral angiography, venography, and venous manometry under conscious sedation. Cerebral angiography is performed with a guide catheter through a femoral arterial puncture. Cerebral venography and manometry are done through femoral vein access, with a shuttle catheter placed at the internal jugular vein. Then, a 0.027-in microcatheter with a 0.014-in microwire is used to gain SSS access past the point of stenosis. Then, an arterial pressure transducer is zeroed and pressures are measured from the segments of SSS, bilateral transverse sinuses, sigmoid sinus, jugular bulb, and cervical internal jugular. Patients with elevated MVPs or significant trans-stenosis pressure gradient  by Higgins et al. in 2003 showed a decrease in the mean pressure gradient from 18.9 to 11.3 cmH2O [2O to 4.4 cmH2O. The initial CSF opening pressure was 35.7 cmH2O  but unfortunately was not able to determine the post-stent CSF pressure [2O resolved to post-stent pressure gradient mean of 1 cmH2O. Resolution of ICPs was also proven with post-stent ICP mean of 17.0 cmH2O [2O gradient. The goal of the venous stenting has been to normalize the trans-stenosis pressure gradient. A pressure gradient of 8-10 cmH studies -34. The .3 cmH2O . A largepressure . In the .0 cmH2O . Within Resolution of SymptomsVSS is still a novel treatment and not used as a first-line treatment; thus, the current data are in medically refractory IIH patients. Higgins and colleagues’ initial report improved headaches, vision, and papilledema in seven of 12 patients. But Higgins’ study suffered from poor patient selection as only three patients underwent pre-stent LP and ~66% had papilledema . As moreOphthalmologic OutcomesCurrent data are especially promising for the ophthalmologic outcomes. Higgins’ study had the worst outcomes for papilledema with only a 62.5% improvement . HoweverComplications2O and 65% stenosis; thus, it was treated [With any vascular stenting, the most feared complication is acute thrombus and stenosis of the stent. This would increase the distal venous pressure and cause either an ischemic or hemorrhagic stroke. Fortunately, there has not been a recorded thrombosis in VSS, even with the use of bare metal stents. Another complication of stents is acute re-stenosis of the stent. Atrial stents are known to collapse within the stent, referred to as in-stent stenosis. However, stenosis in VSS affects the sinus adjacent to the stent, referred to as stent-adjacent stenosis (SAS); this has been documented at the distal end of the stent. The incidence is ~18% of venous stents, but are symptomatic and/or require retreatment/extension in ~10% of times . The rev treated .p = 0.018 & p = 0.031, respectively). As the most common complication of VSS, initial classifications have sought to predict the occurrence of SAS. Raper et al. proposed a three-type classification system . It caten = 2), subdural hematoma (n = 3), transient hearing loss (n = 2), and stent migration (n = 1). Overall, the rate of other adverse effects is 5.4%. A few case reports have discussed individual events [de novo Borden type I dAVF was found draining into the right transverse sinus (TS)/sigmoid sinus (SS) junction. The stenting may have caused hemodynamic changes that resulted in decreased cortical outflow and formation of the dAVF; the VEGF and PDGF expression secondary to VSS-induced inflammation may have promoted the vascular proliferation. It was a low-grade dAVF and thus treated conservatively [Other complications include femoral pseudoaneurysm . Naturally, the VOL drains into the distal transverse sinus or TS/SS junction. Venous stents often span the ostium of VOL. A recent series by Levitt et al. report that the venous stenting does not change the overall venous drainage of the VOL . AnotherBody Mass IndexThe relationship between obesity and IIH has been well established; however, the efficacy of VSS stratified by BMI has just started being explored. Raper et al. retrospectively categorized 50 patients by BMI categories to examine if VSS is equally effective in different BMI groups. In conclusion, it identified a small but direct relationship with BMI and MVP. As for the efficacy, none of the symptoms revealed a statistically significant difference and noted VSS was equally effective throughout the BMI categories. The percentage reduction in the pressure gradient post-stent is similar between the BMI categories (~83%) . Conscious versus General Anesthesia2O) than CS . The MVPs lowered in the distal venous sinuses and increased in the proximal venous sinuses under GA. This significantly lowered the pressure gradient from a mean of 12.1 cmH2O under CS to 8.9 cmH2O under GA (p < 0.001). A subset, however, of patients had their pressure gradient increase under GA and were more likely to normalize after VSS [As VSS becomes more prevalent, various practice differences are emerging between interventionists. From the studies on ICPs, there is a difference between cranial pressure measurements while under conscious sedation (CS) and general anesthesia (GA). These authors, unless in extenuating circumstances, base the treatment decision on the trans-stenosis pressure gradient under CS. A 61-patient retrospective cohort that underwent venous pressure measurement under CS and GA revealed a small but significantly lower MVP under GA , SMART 10-mm diameter stent (Cordis), Protégé Everflex (Covidien), Precise (Cordis), and Wallstent (Boston Scientific) -32. FutuAnticoagulationSince the start of VSS, there have been constant changes in the anticoagulation protocol used throughout the various studies. All the recent studies ensure the patients are dual anticoagulated appropriately prior to the VSS. This usually requires testing of the P2Y12 and ARU levels. Yet, that is where the similarities end; most stop clopidogrel within the first six months while aspirin recommendations range from three months to a lifetime . The praExpanding Venous Stentingde novo stents while 42% had prior transverse sinus stents. By dividing the SSS into four equal segments, Raper and colleagues found the stenosis at S1 segment, closest to the torcula, was more frequent (~93%). Patient symptoms did resolve after SSS stenting; headache, tinnitus, and visual obscurations improved by 66.7%, 63.6%, and 50%, respectively. However, the mean trans-stenosis pressure gradient was only 4.2 cmH2O in this cohort and then decreased to 1.5 cmH2O post-stenting [2O used in the TS-SS segments, this illustrates the importance of patient selection. There are patients who would benefit from VSS outside of IIH, but the difficulty could be in identifying them. In a 250-patient pilot questionnaire by Chandran et al., 81% enrolled in a randomized trial between VSS and CSF shunt. The success of the VSS has been largely due to the careful patient selection. It has proven to be great therapy for IIH patients. As it becomes more commonplace, there will be a search for new and expanding indications. A study by Raper et al. evaluated the safety and efficacy of SSS stenting in non-thrombotic venous occlusive disease. Of the 19 patients reviewed, 58% were stenting . DrasticEhlers-Danlos Syndrome, Hypermobility Typep < 0.0001) in about 77% of the cohort. However, this cohort had a higher incidence of junctional stenosis (~11%). This initial report suggests EDS type III could be another indication for intracranial VSS.Ehlers-Danlos syndrome, hypermobility type  is a hereditary connective tissue syndrome with an unknown genetic mutation diagnosed exclusively by clinical assessment and family history . PatientConclusionVenous sinus stenting is an increasingly utilized technique for venous pathology (i.e .IIH). IIH is a disorder defined by classic symptoms  and elevated intracranial pressure without an identifiable source. The current collection of studies provides mounting evidence that VSS provides symptomatic relief as well as possible disease control. Additional follow-up and further studies are necessary to provide prospective and prolonged data to evaluate the durability of VSS as well as long-term clinical outcomes. Overall, VSS has proven to be valuable adjuvant for elevated intracranial pressure and could be used for more venous pathology.


Background: The objective of this study was to investigate the discriminating value of a range of CSF α‐synuclein species for dementia with Lewy bodies compared with Alzheimer's disease, PD, and cognitively normal controls.Methods: We applied our recently published enzyme‐linked immunosorbent assays to measure the CSF levels of total α‐synuclein, oligomeric α‐synuclein, and phosphorylated α‐synuclein in dementia with Lewy bodies (n = 42), Alzheimer's disease (n = 39), PD (n = 46), and controls (n = 78). General linear models corrected for age and sex were performed to assess differences in α‐synuclein levels between groups. We used backward‐elimination logistic regression analysis to investigate the combined discriminating value of the different CSF α‐synuclein species and Alzheimer's disease biomarkers.Results: CSF levels of total α‐synuclein were lower in dementia with Lewy bodies and PD compared with Alzheimer's disease as well as controls (P < 0.001). In contrast, CSF levels of oligomeric α‐synuclein were higher in dementia with Lewy bodies and PD compared with Alzheimer's disease (P < 0.05) and controls (P < 0.001). No group differences were found for phosphorylated α‐synuclein. In dementia with Lewy bodies and PD, CSF total α‐synuclein levels positively correlated with tau and phosphorylated tau , but not with amyloid‐β1‐42. The optimal combination to differentiate dementia with Lewy bodies from controls consisted of amyloid‐β1‐42, tau, total α‐synuclein, oligomeric α‐synuclein, age, and sex . To differentiate dementia with Lewy bodies from Alzheimer's disease, the combination of tau and oligomeric α‐synuclein resulted in an AUC of 0.83. CSF α‐synuclein species do not contribute to the differentiation of dementia with Lewy bodies from PD.Conclusions: CSF α‐synuclein species could be useful as part of a biomarker panel for dementia with Lewy bodies. Evaluating both oligomeric α‐synuclein and total α‐synuclein in CSF helps in the diagnosis of dementia with Lewy bodies. © 2018 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society. Dementia with Lewy bodies (DLB) is the second most common form of dementia in people older than 65 years. It accounts for 10%‐20% of dementia cases.1‐42 (Aβ1‐42), total tau protein (t‐tau), and phosphorylated tau at threonine 181 (p‐tau) mirror the main neuropathological hallmarks of AD and are well established to aid in the diagnosis of AD.Analysis of cerebrospinal fluid (CSF) biomarkers is increasingly applied in the diagnostic workup of neurodegenerative diseases. CSF amyloid‐βThe discovery of α‐syn as a major component of Lewy bodiesSoluble α‐syn oligomers (o‐α‐syn) could be more useful, because (1) early aggregates, or “soluble oligomers”, of α‐syn might play a more essential role in the pathogenesis of α‐synucleinopathies rather than the late aggregates; (2) oligomeric forms of α‐syn seem to be neurotoxic/more pathogenic in vitro and in vivoThe aim of this study was to assess the diagnostic value of measuring CSF levels of a wide range of different CSF α‐syn species  for the diagnosis of DLB in a well‐established cohort of DLB patients, PD patients, AD patients, and cognitively normal controls using our recently developed assays. In addition, we investigated whether these CSF α‐syn species add discriminatory value to the CSF AD biomarkers.We included 106 participants with available CSF from the Amsterdam Dementia Cohort who had visited the VUmc Alzheimer Center between 2002 and 2015 . Patients with AD and with SCD were matched for age and sex with DLB patients. In addition, data and CSF samples of 46 PD patients and 48 volunteers without neurological symptoms collected for a previous studyThe study was conducted according to the revised Declaration of Helsinki and Good Clinical Practice guidelines and approved by the local ethics committee of the VU University Medical Center. All study participants gave written informed consent for use of their clinical data and biomaterial for research purposes.All patients received a standardized and multidisciplinary workup, including medical history, physical, neurological, and neuropsychological examination, MRI, and laboratory tests. Diagnoses were made in multidisciplinary consensus meetings without knowledge of CSF AD biomarker results.123I–FP‐CIT single‐photon emission computed tomography (SPECT) findings showing presynaptic dopaminergic deficits (n = 32) or slow‐wave activity on electroencephalogram  or was confirmed at autopsy (n = 1). AD patients were diagnosed using the criteria of the National Institute for Neurological and Communicative Diseases AD and Related Disorders Association criteria for probable AD.123I–FP‐CIT SPECT scans (n = 21). Severity of parkinsonism in the “on” state was evaluated using the UPDRS‐III. PD patients were only included if the MMSE and/or neuropsychological assessments did not indicate dementia. Subjects were labeled as SCD when the cognitive complaints could not be confirmed by cognitive testing, and criteria for mild cognitive impairment, dementia or any other neurological or psychiatric disorder known to cause cognitive complaints were not met. To be included as controls in the present study, SCD subjects had to remain cognitively stable for at least 2 years. Cognition at baseline and yearly follow‐up was evaluated with extensive neuropsychological assessment. Healthy volunteers underwent a standardized clinical assessment that included medical history and neurological examination. Cognitive impairment in the healthy volunteer group was excluded using the Cambridge Cognitive Examination scale. SCD subjects and healthy volunteers were analyzed as a single cognitively normal group , as described previously.CSF levels of AβCSF t‐α‐syn, pSer129‐α‐syn, and o‐α‐syn levels were measured using our recently published ELISA assays.U tests, where appropriate.Demographical and clinical characteristics were compared between groups using chi‐square tests, analysis of variance with post hoc Bonferroni tests or Kruskal‐Wallis tests followed by Mann‐Whitney CSF α‐syn levels below the first quartile minus 3 times the interquartile range (IQR) or above the third quartile plus 3 times the IQR were considered outliers and excluded from subsequent analyses  corrected for age and sex with post hoc Bonferroni tests. We examined correlations using bivariate Pearson correlation coefficient within diagnostic groups. We used the Benjamini‐Hochberg procedure to correct for multiple testing. Because of collinearity between t‐tau and p‐tau, only the strongest predictor (t‐tau) was included in the following analyses.Subsequently, we used stepwise linear discriminant function analysis to assess the accuracy of the combined CSF biomarkers in classification of the four groups. Stepwise linear discriminant function analysis identifies canonical discriminant functions based on combinations of biomarkers which contribute maximally to group separation and evaluate how well these canonical discriminant functions discriminate the diagnostic groups.1‐42, t‐tau, t‐α‐syn, o‐α‐syn, pSer129‐α‐syn, age, and sex as predictors. CSF data were Z‐transformed. Therefore, the resulting ORs provide the increased odds per standard deviation increase in biomarker value. For the resulting models, we report AUC, sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), and OR (95% CI) of the individual biomarkers. Sensitivity, specificity, NPV, and PPV were calculated using the classification table .Finally, to assess which subsets of CSF biomarkers performed best in distinguishing DLB from AD, PD, and controls, we performed multivariate logistic regression analyses with backward stepwise selection . DLB was entered as a reference category and AβP < 0.05 was considered significant.All statistical analyses were performed using IBM SPSS software for Mac, version 22.0. A P < 0.05). The sex distribution also varied between the diagnostic groups (P < 0.001). Patients with dementia (AD and DLB) had lower MMSE scores compared with controls and patients with PD (P < 0.001). The GLM showed differences between diagnostic groups for Aβ1‐42, t‐tau, and p‐tau . In contrast, the levels of o‐α‐syn were higher in PD and DLB patients compared with controls (P < 0.001). Moreover, o‐α‐syn was also higher in patients with PD compared with patients with AD (P < 0.001). There were no group differences for pSer129‐α‐syn. The ratios of o‐α‐syn/t‐α‐syn and pSer129‐α‐syn/t‐α‐syn were both higher in PD and DLB patients compared with the ratios in AD patients and controls . Evaluating correlations between α‐syn species and the AD biomarkers, we found a positive correlation between t‐α‐syn and (p)tau in all patient groups , but not in controls. By contrast, levels of o‐α‐syn and pSer129‐α‐syn did not correlate with any of the AD biomarkers. Correlations of the α‐syn species with clinical parameters  are shown in Supplementary Table r = ‐0.42, P < 0.01), but not in any of the other groups. CSF o‐α‐syn did not correlate with any of the clinical parameters. In the DLB group, we found a positive correlation between pSer129‐α‐syn and age  and a negative correlation between pSer129‐α‐syn and MMSE score .Subsequently, by use of Pearson correlations, we evaluated associations between different CSF biomarkers Fig. . For DLB1‐42, t‐tau, t‐α‐syn, and o‐α‐syn together classified 64.5% of all cases correctly in the DLB, AD, PD, and control groups . Figure 1‐42, r = 0.647; t‐tau, r = ‐0.789; p‐tau, r = ‐0.596) and discriminated AD patients and DLB patients from PD patients and controls. We will refer to this function as the dementia function. Canonical discriminant function 2 strongly correlates with the α‐syn species  and adds by discriminating PD patients and DLB patients from AD patients and controls. We will refer to this function as the movement disorders function. DLB is located at the intersection of both the dementia axis and the movement disorders axis.Subsequently, we conducted a discriminant analysis to identify the best combination of biomarkers to classify the four groups. A panel of Aβ1‐42, t‐tau, t‐α‐syn, o‐α‐syn, pSer129‐α‐syn, age, and sex were entered as predictors. The DLB group was used as the reference group in each comparison. Table 1‐42, t‐tau, t‐α‐syn, o‐α‐syn, pSer129‐α‐syn, age, and sex discriminated the DLB group from the controls. Low levels of Aβ1‐42 , high levels of tau , low levels of total α‐syn , and high levels of o‐α‐syn  give a higher risk for DLB compared with controls. For the discrimination between DLB and AD, we found that low levels of tau  and high levels of o‐α‐syn  give a higher risk for DLB compared with AD. Finally, low levels of Aβ1‐42  and high levels of tau  give a higher risk for DLB compared with PD. Receiver operating characteristic curves are illustrated in Supplementary Figure Finally, we used backward‐elimination multiple logistic regression analyses to identify optimal biomarker panels for bilateral comparisons between (1) DLB patients and controls, 2) DLB and AD patients, and (3) DLB and PD patients. Aβ DLB and The major findings of this study are that CSF levels of t‐α‐syn are lower in DLB and PD patients compared with both AD patients and cognitively normal controls, whereas CSF levels of o‐α‐syn are higher in DLB and PD patients. In addition, we observed that CSF t‐α‐syn was associated with t‐tau and p‐tau, whereas o‐α‐syn was not associated with any of the CSF AD biomarkers. Third, we demonstrated that CSF α‐syn species in combination with the AD biomarkers are promising biomarker candidates for DLB.Most previous research on CSF α‐syn in DLB patients focused on t‐α‐syn and generated conflicting results compared with AD patients or controls, with α‐syn levels reportedly increased, decreased, or unchanged (see references 13 and 14 for review). These discrepancies are likely because pf differences in the assay platform, antibodies’ characteristics, CSF collection, storage and processing steps, blood contamination and heterogeneity of patients included in the studies.1‐42 that is thought to mirror increased amyloid deposition in the AD brain. However, the regulation of t‐α‐syn in DLB seems to be more complex. We observed a positive association between tau proteins and t‐α‐syn in DLB, PD, and AD patients, but not in controls. These results concur with previous studies.r = ‐0.42) between t‐α‐syn and MMSE score in PD patients. This finding is in line with previous studies.1‐42 in patients with PD/DLB.1‐42 in patients with PD/PDD.1‐42. In a previous study in early PD patients, no correlation between t‐α‐syn and Aβ1‐42 was found.1‐42 reflect unrelated disease processes. The elevated levels of o‐α‐syn might be associated with increased levels of soluble α‐syn aggregates resulting from a clearance failure.The reduction in t‐α‐syn in DLB and PD patients is likely because of α‐syn aggregation and sequestration in Lewy bodies,1‐42, t‐tau, and p‐tau.1‐42, tau, and p‐tau to improve the differential diagnosis of DLB. Other, yet to be discovered potential biomarker candidates or posttranslationally modified α‐syn species, may also be useful for this purpose.Although differences in t‐α‐syn and o‐α‐syn were found between diagnostic groups, there is substantial overlap of individual α‐syn levels, which limits the diagnostic value of α‐syn species for individual patients. A potential confounding factor is the overlap in histopathology in neurodegenerative diseases. Neuropathological studies reported the presence of α‐syn pathology in 20%‐50% of AD patients.123I–FP‐CIT SPECT findings showing presynaptic dopaminergic deficits and/or slow‐wave activity on EEG. Furthermore, the cohort was relatively large for a CSF biomarker study. Third, our assays are sensitive, highly target specific, and robust. Among the limitations is the lack of postmortem validation in most patients. Only one DLB patient underwent postmortem examination. Another limitation is the use of erythrocytes instead of hemoglobin to measure the contamination of red blood cells in CSF. The erythrocytes were measured in the first 2 mL of CSF during routine analysis and might not reflect the actual erythrocyte count in the CSF sample used to measure α‐syn species. Using this procedure we may have overestimated the actual erythrocyte count. To note, as we excluded all CSF samples with an erythrocyte count ≥ 500 cells/μL, it is unlikely that traces of blood may have influenced CSF α‐syn levels in our study.One of the strengths of this study is that the diagnosis of PD and DLB was supported by In conclusion, DLB is a disease entity that is located at the crossroads of dementia disorders and movement disorders. We here shown that CSF α‐syn species, especially t‐α‐syn and o‐α‐syn, in combination with the AD biomarkers could be useful as part of a biomarker panel to support DLB diagnosis. This approach would allow for better and timelier diagnosis, characterization of disease subtypes, patient selection for clinical trials that are designed to evaluate new disease‐modifying treatments, and treatment monitoring. An important next step is to prospectively validate CSF α‐syn species in patients at an early disease stage or in a prodromal phase.Inger van Steenoven: 1B, 1C, 2A, 2B, 3A.Nour Majbour: 1C, 3B.Nishant Vaikath: 1C.Henk Berendse: 2C, 3B.Wiesje van der Flier: 2A, 2C, 3A, 3B.Wilma van de Berg: 1A, 1B, 2C, 3B.Charlotte Teunissen: 1A, 1B, 2C, 3A, 3B.Afina Lemstra: 1A, 1B, 2C, 3A, 3B.Omar El‐Agnaf: 1A, 1B, 2C, 3B.Dr. Teunissen serves on the advisory board of Fuijirebio and Roche, received research consumables from Euroimmun, IBL, Fujirbio, Invitrogen and Mesoscale Discovery, and performed contract research for IBL, Shire, Boehringer, Roche and Probiodrug; and received grants from the European Commission, The Dutch Research Counsil (ZonMW), Association of Frontotemporal Dementia/Alzheimer's Drug Discovery Foundation, ISAO and the Alzheimer's Drug Discovery Foundation.Dr. van der Flier performs contract research for Biogen MA Inc. Research programs of dr. van der Flier have been funded by ZonMW, NOW, EU‐FP7, EU‐JPND, Alheimer Nederland, Cardiovasculair Onderzoek Nederland, stichting Dioraphte, Gieskes Strijbis fonds, Boehringer Ingelheim, Piramal Neuroimaging, Roche BV, Janssen Stellar, and Combinostics. All funding is paid to her institution.The remaining authors report no actual or potential conflicts of interest.Supporting InformationClick here for additional data file.


Emerging evidence suggests that α-synuclein (α-syn) aggregation and intercellular transmission contributes to pathogenesis of Parkinson’s disease (PD) and the toxic fibrillary α-syn binds lymphocyte-activation gene 3 (LAG3) receptor that mediates α-syn transmission. The deletion of LAG3 in animal models was shown to limit α-syn spreading and alleviate the pathological changes of dopaminergic neurons and animal behavioral deficits induced by α-syn aggregation. However, little is known about the genetic association of LAG3 variation with human PD development.Here we investigated LAG3 single nucleotide polymorphisms (SNPs) and examined the levels of soluble LAG3 (sLAG3) of CSF and serum from Chinese PD patients.We enrolled 646 PD patients and 536 healthy controls to conduct a case-control study. All the participants were genotyped using Sequenom iPLEX Assay and the partial cerebrospinal fluid (CSF) and serum samples were assessed by Meso Scale Discovery electrochemiluminescence (MSD-ECL) immunoassay to measure sLAG3 concentration.p = 0.001) and rs951818-CC  genotype frequencies were found higher in the female PD patients than controls, respectively, and a strong linkage disequilibrium (LD) was calculated on the variants. The level of sLAG3 in CSF of PD patients was found to significantly differ from that of controls . Meanwhile, the concentration of α-synuclein in CSF of patients was significantly lower than that of controls  and the level of sLAG3 was detected to be positive correlation with that of α-synuclein in the control group , but not in PD group .As a result, distributions of rs1922452-AA  1.311–2.888, In summary, our data suggested that LAG3 SNPs increase the PD risk of Chinese female population and the sLAG3 may be a potential biomarker predicted for PD development. But thehe world .−/− mice delayed the α-syn PFF-induced loss of dopamine neurons and presented animal biochemical and behavioral changes [Lymphocyte-activation gene 3 (LAG3) gene maps to chromosome 12p13 and mainly regulates the immune system as major histocompatibility complex (MHC) class II ligand evolutionarily related to cluster of differentiation 4 (CD4) T lymphocytic reaction . A recen changes . Based o changes . Recent  changes . This ex changes  A series changes . A disor changes . More thTill now, there was no investigation to explore the possible influence of LAG3 variants on the Chinese PD population, although there were three variants of LAG3 such as rs1922452, rs951818, and rs870849 were identified as a potential risk factor to multiple sclerosis (MS) , 14. HerA total of 1182 subjects were enrolled in this study, including 646 PD patients and 536 controls. PD patients fulfilled the clinical diagnosis of PD according to the UK Parkinson Disease Society Brain Bank criteria. The exclusion criteria for the control group were tumors, infections, autoimmune diseases, and other neurodegenerative diseases. All samples were obtained from the Departments of Neurology of the first affiliated hospital at Guangzhou Medical University from 2014 to 2017. DNAs were purified under the standard protocols provided by Blood DNA Kit manufacturer  and the genotyping was analyzed at the Beijing Genomics Institute (BGI) Co., Ltd. .All the subjects wrote their agree-statement forms and the project was approved by the Ethics Committee of the first affiliated hospital of Guangzhou Medical University.CSF samples were collected from 21 healthy controls and 58 patients with PD. Serum samples were obtained from 61 healthy controls and 78 PD patients. Those with a history of tumors, infections, autoimmune diseases, and other neurodegenerative diseases were excluded, as these diseases may affect sLAG3 levels. While blood tubes were centrifuged at 3000 rounds per minute for 10 min at 4 °C, the serum was separated into collection tubes. CSF and serum samples were aliquoted and stored at − 80 °C. Analyzers were blinded to all serum and CSF samples and participants’ information. The levels of sLAG3 and α-synuclein were measured using the Meso Scale Discovery electrochemiluminescence (MSD-ECL) immunoassay. All the samples were run in duplicate.t tests or Mann-Whitney U test was used to assess the difference of continuous variables between PD and control groups. Other variables for gender, genotype and allele distribution were analyzed with chi-squared (χ2) test or Fisher’s exact test. The diagnostic performance was assessed by the AUC of the ROC curve. Cutoff values were calculated using sensitivity and specificity that maximized Youden’s index. The correlations were evaluated using linear regression analysis (Spearman’s correlation). p < 0.05 was considered significant. The statistical power was calculated using QUANTO software version 1.2.4 , but no difference of serum sLAG3 was found in the two groups . Since LAG3 variations were confirmed to be associated with female PDs, we next analyzed the correlation between the level change of sLAG3 and that of α-syn in CSF on males and females separately. As a result, no correlation was detected on male and female patients or controls  and PD patients  by MSD-ECL examination. Data represented as mean ± SD, p = 0.484.Additional file 3: Figure S3. Alterations in CSF sLAG-3 levels in male and female patients and controls. A: The concentration of CSF sLAG-3 in female subjects  and male subjects  and PD patients  by MSD-ECL examination. Data represented as mean ± SD, p = 0.411. C: sLAG-3 levels of CSF in female control subjects  and PD patients  by MSD-ECL examination. Data represented as mean ± SD, p = 0.617.Additional file 4: Figure S4. Correlation of CSF sLAG-3 with serum sLAG-3.Additional file 5. The statistical power of the sample. The power was greater than 0.99, p = 0.000015.


Here, the performance of IrO2 nanoparticles formed and deposited in situ onto carbon nitride support for PEM water electrolysis was explored based on previous preliminary studies conducted in related systems. The results revealed that this preparation route catalyzed the decomposition of the carbon nitride to form a material with much lower N content. This resulted in a significant enhancement of the performance of the gCNH-IrO2 (or N-doped C-IrO2) electrocatalyst that was likely attributed to higher electrical conductivity of the N-doped carbon support.Carbon nitride materials with graphitic to polymeric structures (gCNH) were investigated as catalyst supports for the proton exchange membrane (PEM) water electrolyzers using IrO Moreover, the hydrogen produced is 100% pure and could be used for fuel cell vehicles without further treatment. However, only ~4% of hydrogen is produced from water electrolysis and other lower-cost methods are preferred, such as steam reforming of natural gas [Among the different ways to produce high-purity hydrogen, proton-exchange water electrolysis currently constitutes the most promising and efficient solution. First developed by General Electric Co. in 1966 for space applications [RH) is required. The standard potential of a water electrolysis cell is −1.23 V (E0cathode − E0anode) versus SHE (the standard hydrogen electrode). In practice, the process is kinetically controlled, and an overpotential that overcomes losses due to activation energy, charge and mass transfer, surface blockage, and ohmic losses is required for the reaction to take place:In a water electrolyzer system, the water is split into hydrogen and oxygen. However, this reaction is not thermodynamically favorable and the application of external electrical energy , and Ir and Ru at the anode . Iridium oxide and ruthenium oxide have been established to be among the most active electrocatalysts for water oxidation, with IrOolutions . Some ofg others ,13,14,15g others ,18,19,20Another way to achieve high activity while reducing the loading of noble metal is the use of advanced catalyst support materials ,23,24,25Our own work has recently demonstrated that graphitic or polymeric carbon nitride (gCNH) compounds show promising performance characteristics as support materials for Pt catalysts in PEM fuel cells ,42,43,446N7) ring units linked by three-coordinated nitrogen and –NH– bridges to form zigzag chains and partial sheet formation [2 supported on polymeric gCNH in a PEMWE cell revealed an enhancement in the charge-transfer resistance as the current density increases when compared to unsupported IrO2. This was attributed to a higher active surface area of the catalyst nanoparticles (NP) on the carbon nitride support [Composed of C and N atoms, along with some residual amounts of H, gCNHs are semiconducting materials with a band gap of ~2.3 eV ,48,49,50ormation  2, which is then oxidized to form PtO2 nanoparticles (NP) that can be deposited on a support material [The Adams fusion method is widely used to deposit PtOnd NaNO3 ,52,53. Tmaterial ,53.2 NPs were produced using a similar approach and the process was monitored using thermogravimetric analysis (TAG) and differential scanning calorimetry (DCS) techniques (4)2IrCl6 to Ir(NO3)4 accompanied by the formation of NaCl and NH4NO3:In our work, IrOchniques a. An exo4NO3 formed then spontaneously decomposes via an exothermic reaction:The NH3)4 to IrO2.Above ~640 °C, an abrupt loss of mass is observed associated with the final conversion of Ir patterns for each of the resulting powders were obtained (4)2IrCl6 had completely reacted and been oxidized to IrO2, and the material exhibited broad diffraction peaks corresponding to an average crystallite size of 4 nm, estimated using the Scherrer formula. IrO2 crystallizes in the rutile structure . The broad peaks observed at 32°, 37°, and 55° 2θ in the XRD pattern of the material prepared at 400 °C can be indexed as the (110), (101), and (211) reflections of nanocrystalline IrO2, respectively. The formation of IrO2 was signaled by an exothermic peak in the DSC diagram, accompanied by a ~19% weight loss in the TGA trace. By 600 °C, the material showing well-defined peaks matching the IrO2 rutile crystalline structure had sharpened, indicating a crystallite size that had increased to ~7 nm. At this temperature, additional reflections corresponding to the (200) and (220) reflections of IrO2 were also observed at 42° and 59° 2θ, respectively. At 900 °C, the sharp diffraction peaks indicated larger particle sizes on the order of ~30 nm  composite compared with 1.85 V obtained for IrO2 NPs at the same current density. However, electrochemical impedance measurements did indicate that the gCNH-IrO2 composites showed enhanced charge transfer kinetics as the current density was increased, thus, suggesting ways to improve the EC performance [2 nanoparticles onto the gCNH substrate, a high-performance EC anode behavior could be obtained.In a previous preliminary study, we had reported the preparation of gCNH-nano-IrOpropanol . These mformance . Our res2 nanoparticles onto gCNH support material that was already present in the reaction mixture. For these syntheses, the carbon nitride powder was prepared by thermolysis of dicyandiamide/melamine (1/1) precursors at 550 °C for 15 h under N2 (g) and then dispersed in isopropanol before adding (NH4)2IrCl4 and NaNO3 to the mixture. The isopropanol was evaporated and the resulting mixture was heated in stages while studying the course of the reaction by TGA/DSC  reflection near 35° 2θ. The weak carbon nitride feature was no longer visible in the pattern. At 400 and 450 °C, the main phase present was IrO2 with small nanoparticle size, while XRD reflections from Ir metal remained visible in the pattern recorded at the highest temperature. The large weight loss recorded while the IrO2 is being formed can be attributed to the decomposition of the gCNH support material, with the removal of a large proportion of its N component. This is an interesting result because gCNH materials prepared from the thermolysis of precursors are normally found to be stable against decomposition in the air at temperatures up to ~650 °C [2 NPs in the system can catalyze the decomposition of the carbon nitride support, resulting in a material that corresponds more closely to an electrically conducting N-doped graphite rather than the expected gCNH semiconductor. That would be a desirable outcome for improving the electrochemical performance.In order to achieve this, we initiated the present study to carry out the formation and deposition reactions of the IrO TGA/DSC c, with aNH phase d. After  ~650 °C . Our res2 nanoparticles, we conducted a TGA/DSC study of the synthesis experiment in the absence of gCNH under the same conditions as those shown in 3 to the mixture 2IrCl6 took place as before, although a different set of processes was observed to occur. In this case, the (NH4)2IrCl6 first undergoes decomposition to IrCl4(NH3)2 with the release of HCl at around 400 °C, followed by the formation of IrCl4 and 2NH3 at ~450 °C, with the final oxidation to IrO2 occurring at ~480–500 °C 2IrCl6 combination, we observed a mass loss of ~80% with onset at 450 °C 2IrCl6 system, the TGA/DSC also showed a higher weight loss than in the case of the (NH4)2IrCl6 alone. However, no abrupt loss of weight was observed at 500 °C, but instead, a gradual decrease in mass with increasing temperature was observed  catalyst supports dispersed in isopropanol, again without adding NaNOt 450 °C c, that it 450 °C d. The gCobserved e. XRD ant 900 °C f.2 and gCNH [2 NPs in situ in the presence of the gCNH support material  ball-milled sample the C, N, Ir, and O elemental contents determined by bulk analysis closely matched those of the starting materials, as expected [2 was prepared and deposited in the presence of the gCNH support material, the results are quite different  compared with a theoretical N composition of 52.7 wt % for the gCNH phase  analyses support this finding . The gCN.26 at % c,d.2 bonded C atoms associated with triazine or heptazine ring units in the carbon nitride (N-C=N) [The C 1s spectra a,b for b (N-C=N) . The oth (N-C=N) . The mag2) groups, or N atoms bridging between three heptazine rings (N-C3 units) [The N 1s spectra show a similar trend, both exhibiting a dominant feature near 398.8 eV that is assigned to C-N=C units within either triazine or heptazine rings and a smaller contribution at 400.8 eV appearing as a shoulder, indicative of the C-N-H uncondensed amino (-NH3 units) . HoweverThe ratio of the N peak at ~399 eV and the C peak at ~288 eV should be close to 1:1 if both are attributed to C-N=C units, as is the case for the ball milled material. However this ratio changes to 1:13 for the material prepared by the Adams’ fusion method at 450 °C, showing that the C peak cannot be attributed to triazine/heptazine units. This material shows evidence for an increased O concentration so that the major contribution to the peak at ~288 eV can be attributed to carboxy-groups.2 (40%) prepared by ball milling (1.6 mg cm−2) exhibited an onset potential of 1.53 V and potential of 2.30 V at 0.42 A cm−2 [−2 due to the high overpotential already reached at lower current densities. x anode that was used as a benchmark for the study, an MEA with a gCNH-IrO2 anode prepared at 400 °C, and an MEA with gCNH-IrO2 anode prepared at 450 °C. In all cases, Pt/C was used as the cathode material for the hydrogen evolution reaction.Electrochemical tests of the anode composites were carried out in a PEM water electrolyzer cell. Previous studies have shown that the gCNH-IrO2 A cm−2 . This ma2 catalyst prepared at 400 °C MEA exhibited excellent performance at low current densities (<0.7 A cm−2), with a cell potential of 1.6 V at 0.2 A cm−2. As the current density was increased, the cell potential of the gCNH-IrO2 at 400 °C MEA also increased, giving a final cell potential of 1.93 V at 1 A cm−2, the highest current density tested in these experiments. This value was slightly higher than that obtained for the commercial MEA (1.90 V). In the case of the gCNH-IrO2 (450 °C) MEA, although the cell potential is slightly higher than the cell with the gCNH-IrO2 (400 °C) MEA, it was lower than the commercial MEA and it showed better performance at higher current densities, achieving cell potential values similar to the commercial IrRuOx MEA.As shown in the three polarization curves in 2 400 °C MEA exhibits the highest cell resistance (elR) (0.285 Ω cm2) of the three catalysts at a current density of 0.1 A cm−2 -gCNH at 450 °C; 0.243 Ω cm2), which explains the higher slope of the polarization curve that results in a higher cell potential at 1 A cm2.The electrochemical performance of the three MEAs was further interpreted by analyzing the electrochemical impedance spectroscopy (EIS) data . It can 2 400 °C MEA exhibited the highest resistance at both current densities considered. This would explain its poorer performance compared to the other two MEAs. The fitted parameters showed that at 0.1 A cm−2, the ctR (charge transfer resistance) of the three MEAs increased from 0.200 Ω cm2 (gCNH-IrO2 400 °C) to 0.210 Ω cm2 (gCNH-IrO2 450 °C) and 0.216 Ω cm2 (IrRuOx) (2 at 400 °C at a low current density. The EIS spectra recorded at 1 A cm−2 exhibited features corresponding to mass transport limitations at low frequencies that can be attributed to the formation of oxygen and hydrogen bubbles in the electrolyzer cell.The gCNH-IrO(IrRuOx) , which e2N4H4, Sigma Aldrich, Dorset, UK) and melamine  at 550 °C. The finely ground starting mixture was loaded in an alumina boat into a quartz tube in a tube furnace under a flow of nitrogen. The furnace temperature was raised at 5 °C min−1 and held for 15 h. The furnace was allowed to cool to room temperature before the product was removed. Further details of the synthesis and characterization of this material are given elsewhere [Polymeric carbon nitride was prepared by thermolysis and condensation reactions of a 1:1 molar ratio mixture of dicyandiamide 2IrCl6  was dissolved in isopropanol  to achieve a final metal concentration of 4 × 10−2 M, and was magnetically stirred for 2 h. An excess of finely ground NaNO3  was added to the solution, which was further stirred for 1 h. The mixture was thermally treated at 500 °C for 1 h in air. The obtained black powder was washed several times with boiling deionized water to remove the unreacted NaNO3. The IrO2 powder was dried at 80 °C overnight.IrOarticles ,54,55. T2 was also prepared following Adams’ fusion method, but with the gCNH material dispersed in isopropanol before the (NH4)2IrCl4 was added. The amount of Ir salt added was calculated to result in 20 wt % IrO2 in the final composite. As previously, an excess of finely ground NaNO3 was added to the solution, which was further stirred for 1 h. In order to study the effect of the synthesis temperature on the final composite, the mixture was thermally treated at 400 °C and 450 °C for 1 h in air, and the two corresponding materials were labelled as gCNH-IrO2 400 °C and gCNH-IrO2 450 °C. The obtained black powders were then washed several times with boiling deionized water to remove the unreacted NaNO3, and dried at 80 °C overnight. The results were compared with those for a commercial IrRuOx electrocatalyst.The composite gCNH-IrO−2 of Pt. The active area of the prepared MEAs was 7.07 cm2.Nafion 115  was used as the PEM for the MEA preparation. Following a standard procedure, the Nafion membrane was pre-treated in hydrogen peroxide (5 wt %) at 80 °C for 1 h to remove organic impurities. After being flushed with deionized water, it was transferred into a 0.5 M sulfuric acid solution and boiled at 80 °C for an additional 1 h to protonate the membrane. Finally, the membrane was washed with deionized water. The catalyst inks were prepared by dispersing the catalyst powder into a mixture of water and Nafion solution 10% (Sigma Aldrich) and ultrasonically dispersed for 2 h before being used. All the MEAs used in this study were prepared by spraying the catalyst ink onto the Nafion membrane using an air-driven spray gun. Catalyst loading for the cathode was 4 mg cmC, N, and H analyses were performed using a Carlo-Erba EA1108 system . Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analyses were performed on a Netzsch DSC/TGA instrument . Transmission electron microscopy (TEM) images were taken using a JEOL JEM2010 instrument  operating at 200 kV; the samples were prepared by dispersing the particles in methanol and evaporating the suspension drops on holey carbon grids .−1 was supplied to both anode and cathode. Polarization curves were recorded galvanostatically between 0 and 1 A cm−2 at a 10−3 A s−1 scan rate. Electrochemical impedance spectroscopy (EIS) measurements were carried out potentiostatically at 0.1 and 1 A cm−2 with an amplitude of 5 mV in the frequency range of 10 MHz to 10 kHz. All electrochemical measurements were performed using an Autolab PGSTAT 30 Potentiostat/Galvanostat  equipped with a frequency response analyzer (FRA).A PEM water electrolyzer cell supplied by ITM-Power was used to investigate the electrochemical performance of the prepared MEAs at an operating temperature of 80 °C. Preheated deionized water (18.3 MΩ cm) circulated by two peristaltic pumps at a flow rate of 150 mL min2, catalyzing the water oxidation reaction taking place at the anode. IrO2 nanoparticles were successfully synthesized and deposited onto support materials. However, it was discovered that the process of forming these IrO2 nanoparticles in situ onto the gCNH support acted to catalyze its decomposition leading to the substantial loss of the N-H component, as corroborated by TGA/DSC, elemental analysis, and XPS and EDS measurements. Together, the results indicate that the carbon nitride has been converted into a highly N-deficient carbon nitride or heavily N-doped graphitic carbon material that should be further investigated in future work. The loss in N from the support resulted in a significant enhancement of the performance of the gCNH-IrO2 (or N-doped C-IrO2) electrocatalyst that we can attribute to a higher electrical conductivity of the support.gCNH materials were investigated as catalyst supports for PEM water electrolyzers, specifically as support for IrO


An increased preoperative talar tilt (TT) angle was reported to be positively correlated with treatment failure after supramalleolar osteotomy (SMOT) for varus ankle osteoarthritis. Distraction arthroplasty was reported to have the ability to correct increased TT angles. The purpose of the current study was to compare the outcomes between SMOT with and without medial distraction arthroplasty (MDA) in the treatment of varus ankle osteoarthritis with increased TT angles.We retrospectively reviewed the functional outcomes and radiological findings of 34 patients who underwent SMOT with or without MDA for varus ankle osteoarthritis with increased TT angles. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and Ankle Osteoarthritis Scale (AOS) scores were used for functional evaluation. The tibial anterior surface (TAS) angle, talar tilt (TT) angle, tibial medial malleolar (TMM) angle, talocrural (TC) angle, tibial lateral surface (TLS) angle, and hindfoot alignment (HFA) angle were evaluated preoperatively and at the time of the last follow-up.P < 0.01 for each) at a mean follow-up of 61 months. The TAS, TT, TC, TLS, and HFA angles were all significantly improved (P < 0.01 for each). Similarly, in the SMOT with MDA group, the AOFAS score, AOS pain and function scores, and the TAS, TT, TC, TLS, and HFA angles were all significantly improved postoperatively (P < 0.01 for each). When comparing the two groups, the postoperative TT angle was significantly smaller in the SMOT with MDA group (P = 0.023) than in the SMOT group. In addition, the failure rate of TT angle correction was significantly higher in the SMOT group (P = 0.016) than in the SMOT with MDA group.In the SMOT group, the AOFAS score and AOS pain and function scores were significantly improved (SMOT is a promising procedure for functional improvement and malalignment correction for varus ankle osteoarthritis, even in patients with increased talar tilt. If SMOT is combined with MDA, there can be an improvement in the correction of the increased talar tilt.Level III, a retrospective comparative study Ankle osteoarthritis is a progressive disease characterized by the degeneration of articular cartilage and often develops asymmetrically with a concomitant varus deformity , 2. The However, the role of the talar tilt (TT) angle on SMOT is controversial. Some studies reported that increased preoperative TT angles were correlated with increased postoperative TT angles , 14–16, Ankle joint distraction arthroplasty was first reported in 1995 by van Valburg and his colleagues  and has The current study was approved by the research board of our hospital. The authors retrospectively studied the outcomes of SMOT with or without MDA in the treatment of varus ankle osteoarthritis with increased TT angles between January 2010 and October 2016. The inclusion criteria were as follows: (1) adults who were at least 18 years of age; (2) patients with a tibial articular surface (TAS) angle of less than 84°; (3) patients with varus ankle osteoarthritis; (4) patients with clinical symptoms, such as pain with walking and limitation of daily and recreational activities; (5) patients with a TT angle larger than 5° ; (6) patP = 0.014). The mean follow-up time in the SMOT group was longer than in the SMOT with MDA group (P < 0.001). There were no significant differences among the other information with the available numbers.Finally, 16 cases in the SMOT group and 18 cases in the SMOT with MDA group were included in the study. There were 11 males and 23 females, and the mean age was 54.8  years. According to the modified Takakura ankle osteoarthritis stage, there were 13 patients with stage 3a osteoarthritis, 19 patients with stage 3b osteoarthritis, and 2 patients with stage 4. The basic information of the included patients is listed in Table All of the included patients were treated with medial opening wedge SMOT. The surgical technique of SMOT for fibular osteotomy has been well described in a previous study . The tibIf the talocrural (TC) angle decreased by more than 5° in comparison with the uninjured site , the fibIf the patient had chronic ankle joint instability or was unstable after lateral osteophyte debridement, a modified Brostrom procedure was used to ensure the lateral stability of the ankle joint. If the patient still had varus deformity of the hindfoot after SMOT, a calcaneal osteotomy was used to further improve the lateral movement of the weight-bearing site in the hindfoot.In the SMOT with MDA group, after the SMOT incisions were closed, an external fixator was applied. One pin was placed into the calcaneus under fluoroscopy, one half pin was placed into the talus from the medial side to the lateral side, and one or two additional pins were placed into the tibia. A fixed external fixator, which allowed further distraction without permitting ankle joint motion, was applied. With the distraction of the talus pin during the operation, the TT angle was corrected to 0° or negative degrees and was verified fluoroscopically.The postoperative rehabilitation protocol included active and passive motion exercises of the ankle and midfoot and forefoot joints, isotonic and isometric exercises of the leg, and the use of a night splint beginning on the second postoperative day in the SMOT group. Patients were permitted to be partially weight-bearing 6 weeks postoperation. Full weight-bearing activities began after the osteotomy site achieved bony union that was confirmed radiographically. The external fixator was used for 10 to 12 weeks in the SMOT with MDA group. The postoperative rehabilitation protocol in the SMOT with MDA group was similar to that of the SMOT group, except that weight-bearing actions and motions of the ankle joint were prohibited. After the external fixator was removed, the patient was permitted to begin partial weight-bearing activities for 1 month and then full weight-bearing activities after the osteotomy site achieved bony union, which was confirmed radiographically.The radiological evaluations visualized the TAS, TT, TC, and tibial medial malleolar (TMM) angles in an anterior-posterior ankle view, the TLS angle in a lateral ankle view, and the hindfoot alignment (HFA) angle in the Saltzman view Fig. . All of The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and the Ankle Osteoarthritis Scale (AOS) were used to evaluate the functional outcomes preoperatively and postoperatively , 24. TreTo analyze the changes in the radiographical grade, stages 1, 2, 3a, 3b, and 4 of the modified Takakura classification system were assigned quantitative scores of 1, 2, 3, 4, and 5, respectively.t test, Pearson’s chi-square test, or Fisher’s exact test with the level of significance set at α = 0.05. The statistical analyses were performed with SPSS 17.0 software .Descriptive statistics were calculated as the means ± standard deviation. Statistical analyses of the included data were performed using Student’s P < 0.001, Table P < 0.01). However, the range of motion (ROM) of the ankle joint was not significantly improved with the available numbers. The modified Takakura stages in both groups decreased significantly (P < 0.001). In both groups, all of the radiological parameters, including the TAS, TT, TMM, TC, TLS, and HFA angles, improved significantly (P < 0.05).All patients in both groups achieved bony unions without incision-related complications. No patient in either group had other soft tissue complications. Pin tract infections of the tibia occurred in two patients in the SMOT with MDA group. Both of these patients were treated with dressing changes and oral antibiotics; no patient needed early removal of the external fixator. When compared with the preoperative conditions, both groups achieved significant improvement in the AOFAS scores . All of the TT angles in the SMOT with MDA group were corrected to normal angles (≤ 4° [P = 0.016). Among these five patients, two patients had fused joints, two were still symptomatic and treated conservatively, and only one reported a good outcome. The other postoperative radiological parameters, including TAS, TMM, TC, TLS, and HFA angles, were not significantly different with the numbers available.When comparing the postoperative radiological parameters of the two groups, the TT angle in the SMOT with MDA group was significantly smaller than that of the SMOT group Osteoarthritis is a slowly progressive degenerative joint disorder that, in most cases, is diagnosed at a late stage after the onset of accompanying clinical symptoms. Ankle joint osteoarthritis is one of the most common joint diseases and is a significant source of pain and disability for middle-aged and elderly people throughout the world . Joint-sTalar tilt is common in varus ankle osteoarthritis and is not a bony deformity that results in the incongruence of the tibiotalar joint. The initial reason for the increased TT angle may be due to a lateral collateral ligament injury of the ankle joint. However, this will result in a medial shift of the center of the talus and joint loading axis  and willJoint distraction arthroplasty in the treatment of severe ankle osteoarthritis shows significant and prolonged improvement in pain and functional ability in open prospective studies as well as in a randomized controlled trial , 33. OurTo the best of our knowledge, this is the first study to report the functional and radiological outcomes of combining SMOT and distraction arthroplasty to correct varus ankle osteoarthritis with large varus TT angles and is the first study to compare the results of this technique with SMOT. According to the current results, SMOT alone has a high rate of failed correction of the TT angle  5 years previously. Other limitations included a relatively small sample size and a large age range in the included patients, which may result in heterogeneity. Although the outcomes will change over time, our early results confirmed that the functional outcome of the SMOT procedure is good in terms of alleviating pain relief, correcting the malalignment, and reducing the signs of varus ankle osteoarthritis patients with increased TT angles. In addition, the combined use of SMOT and distraction arthroplasty could better correct the TT angle.In conclusion, SMOT combined with MDA can improve the clinical and radiological outcomes of varus ankle osteoarthritis with large TT angles. This procedure may be helpful to restore the weight-bearing alignment of the ankle joint and to correct the TT angle that opens the medial ankle joint space. However, well-designed prospective comparative studies are still needed to further confirm the outcomes of medial distraction for increased TT angles.


GRN) mutation carriers. Levels of soluble triggering receptor expressed on myeloid cells 2 (sTREM2) are elevated in Alzheimer’s disease (AD), but they have not been fully explored in FTD.Reliable biomarkers of frontotemporal dementia (FTD) are currently lacking. FTD may be associated with chronic immune dysfunction, microglial activation and raised inflammatory markers, particularly in progranulin . Ten of 64 had familial FTD, with mutations in GRN (n = 3), MAPT (n = 4), or C9orf72 (n = 3). Fifteen of 64 had neurodegenerative biomarkers consistent with AD pathology (11 of whom had logopenic variant PPA). Levels were compared using multivariable linear regressions.We investigated whether cerebrospinal fluid (CSF) sTREM2 levels differ between FTD and controls, across different clinical and genetic subtypes of FTD, or between individuals with FTD due to AD versus non-AD pathology (based on CSF neurodegenerative biomarkers). We also assessed relationships between CSF sTREM2 and other CSF biomarkers  and age and disease duration. Biomarker levels were measured using immunoassays in 17 healthy controls and 64 patients with FTD  and MAPT  mutation carriers. Individuals with AD-like CSF had higher sTREM2 levels than those with non-AD-like CSF . CSF sTREM2 levels were associated with T-tau levels in control and FTD groups and also with P-tau in those with FTD and AD-like CSF. CSF sTREM2 levels were influenced by both age and disease duration in FTD.CSF sTREM2 levels did not differ between FTD and controls or between clinical subgroups. However, GRN mutations and in FTD syndromes due to AD pathology. Because CSF sTREM2 levels correlate with a marker of neuronal injury (T-tau), sTREM2 should be explored as a biomarker of disease intensity in future longitudinal studies of FTD.Although CSF sTREM2 levels are not raised in FTD overall or in a particular clinical subtype of FTD, levels are raised in familial FTD associated with  GRN), microtubule-associated protein tau (MAPT) or chromosome 9 open reading frame 72 (C9orf72) ). Around one-third of cases are familial, associated most commonly with mutations in progranulin C9orf72) . Patholo . Patholutations , 4. InflTREM2 mutations lead to a rare syndrome called Nasu-Hakola disease  = 9.0 [3.6] ng/ml) compared with the other two groups  , adjusting for age and sex. The difference in CSF sTREM2 levels between these two subgroups was affected by disease duration, with differences becoming more obvious as disease duration increased , and there was no difference between the AD biomarker-negative subgroup and controls .In the pathological subgroup analysis, there was a trend towards a difference in CSF sTREM2 levels between the three groups (ml) Fig. . There wsed Fig. . A β valD] = 9.0 .6 ng/ml)sed Fig. , althougP = 0.033)      , P-tau  and Aβ42 . After stratifying the dementia group by CSF AD biomarker profile, there was an association between CSF sTREM2 and CSF T-tau in both pathological subgroups  , but not in the AD biomarker-negative subgroup  , but not in the AD biomarker-positive subgroup   Fig. , but not25) Fig.  or Aβ42 58) Fig.  levels. 01) Fig. , P-tau (02) Fig.  and Aβ4233) Fig. . CSF sTR02) Fig. , adjusti84) Fig. , and, in83) Fig. .Fig. 2ReP = 0.001)   . In the clinical subgroup analysis, there was no significant difference between the coefficients for age by clinical subgroup (P = 0.964), and after adjusting for sex and disease duration, the association with age was generally similar in the majority of subgroups . In the pathological subgroup analysis, CSF sTREM2 levels were associated with age in both the AD biomarker-negative  and AD biomarker-positive  dementia subgroups. When we assessed interactions between pathological subgroup and age, there was no significant difference between the coefficients for age by subgroup (P = 0.528).CSF sTREM2 levels were positively associated with age at CSF collection in the whole cohort  Fig.  and in i01) Fig. . In the 91) Fig. , but theups Fig.  (bvFTD βP = 0.025) , but no significant association was seen in other clinical subgroups . In the pathological subgroup analysis, there was a significant difference in the coefficients for disease duration between the two dementia subgroups (P = 0.027). There was a significant negative association between CSF sTREM2 level and disease duration in the AD biomarker-negative subgroup  but a trend towards a positive association in the AD biomarker positive subgroup . This resulted in the difference in CSF sTREM2 levels between these two subgroups increasing as disease duration increased  Fig. . In the ups Fig. . Despitesed Fig. .P = 0.992), or in controls, dementia, or any of the clinical or pathological subgroups, apart from in the svPPA subgroup, where males had higher sTREM2 levels than females .CSF sTREM2 levels did not differ by sex within the whole cohort  and compared with cognitively normal controls. This adds to previous studies of raised inflammatory CSF markers in familial FTD, particularly in GRN mutation carriers [GRN mutations had higher CSF sTREM2 levels than those with MAPT or C9orf72 mutations, and compared with controls. This may be due to a link between GRN and TREM2, both of which are expressed by microglia, and thought to regulate microglial function and immune pathways in general. GRN-knockout mice have upregulated TREM2 gene expression [GRN mutations and patients with heterozygous GRN mutations display excessive microglial activation on post-mortem brain tissue analysis [GRN haploinsufficiency could lead to enhanced TREM2 expression by microglia, increasing release of sTREM2 into the CSF and promoting survival of dysfunctional microglia or exacerbating neuronal damage through excessive phagocytosis.We included a number of individuals with familial FTD in our study, enabling an exploratory analysis of differences in CSF sTREM2 between individuals with the three most common mutations linked to FTD , hyperphosphorylated tau (P-tau) and amyloid pathology (Aβ42). In individuals with FTD but likely AD pathology, higher CSF sTREM2 levels were associated with higher CSF T-tau and P-tau levels. This is consistent with associations between CSF sTREM2 and T-tau and/or P-tau levels in amnestic AD , 24, 25,We also examined relationships between sTREM2 levels and relevant clinical parameters such as age, disease duration and sex, which may affect TREM2 expression. The positive association between CSF sTREM2 levels and age in FTD is consistent with studies of AD –25. IncrBecause previous research has shown that CSF sTREM2 levels vary by disease stage in mild cognitive impairment and AD , 25, we Although CSF sTREM2 levels did not differ by sex within our whole cohort or in our dementia or control groups, there was a difference in the svPPA subgroup, with higher CSF sTREM2 levels in males. The majority of studies focusing on AD have not found an association between CSF sTREM2 levels and sex , 23–25, A limitation of our study is that some of the FTD clinical and genetic subgroups were rather small, which may have limited our power to detect significant differences between groups. However, this is inherent to a disease such as FTD, where rarer subtypes exist, and it is difficult to avoid when analysing biomarker levels across a broad clinical and pathological spectrum of disease and when employing CSF collection and biomarker analysis at one centre in order to minimise inter-centre variation. Other studies with multi-centre CSF sources have shown significant variability in sTREM2 levels between centres , which wGRN mutations  and in individuals with a clinical syndrome consistent with FTD but underlying AD, rather than FTLD, pathology. Because CSF sTREM2 levels correlate with a measure of neuronal injury (T-tau), they may reflect disease intensity in FTD, but this requires further exploration.Although CSF sTREM2 does not seem useful for differentiating between individuals with FTD and healthy controls, or for delineating a particular clinical subtype of FTD, levels are higher in familial FTD associated with GRN, MAPT and C9orf72 (which have known pathology) would be helpful in this regard and would enable confirmation of our preliminary observations of higher levels in symptomatic GRN mutation carriers. Assessment of CSF sTREM2 levels in pre-symptomatic individuals at risk of familial FTD could establish if and when levels change prior to expected symptom onset. This would help to elucidate whether CSF sTREM2 levels may be useful as a biomarker of disease proximity in FTD, which, if validated, may be useful for guiding timely initiation of treatments or assessing treatment response in clinical trials. This would maximise the chance of benefitting individuals before significant neurodegeneration occurs. Exploration of relationships between baseline and longitudinal measurements of CSF sTREM2 levels and other markers of disease intensity  would also enable determination of whether CSF sTREM2 can be used as a biomarker of disease intensity in sporadic or familial FTD.Future studies should analyse CSF sTREM2 levels within larger cohorts of individuals with FTD, across a variety of clearly defined clinical subgroups, and ideally in pathologically confirmed cases. Inclusion of a larger number of familial FTD cases with mutations in


GDAP1 gene cause autosomal dominant and autosomal recessive Charcot-Marie-Tooth (CMT) disease and over 80 different mutations have been identified so far. This study analyzed the clinical and genetic characteristics of a Vietnamese CMT family that was affected by a novel GDAP1 mutation. Mutations of GDAP1 gene was requested for all members of the family. We present three children of a family with progressive weakness, mild sensory loss, and absent tendon reflexes. Electrodiagnostic analyses displayed an axonal type of neuropathy in affected patients. Sequencing of GDAP1 variant (c.667_671dup) was found in the three affected children as recessive inheritance pattern. The mutation leads to a premature termination codon that shortens GDAP1 protein (p.Gln224Hisfs∗37). Further testing showed heterozygous c.667_671dup variant in the parents. All affected individuals manifested identical clinical symptoms of motor and sensory impairments within the first three years of life, and nerve conduction study indicated the axonal degeneration. A homozygous GDAP1-related CMT disease with the new and unreported GDAP1 variant. Alterations in GDAP1 gene should be evaluated as CMT causing variants in the Vietnamese population, predominantly axonal form of neuropathy in CMT disease. Our study expands the mutational spectrum of PMP22 gene, while the mutation spectrum in CMT2 is more diverse including variants in MFN2, MPZ, GJB1, and GDAP1 and a large number of additional genes [Charcot-Marie-Tooth disease (CMT) is one of the most common inherited peripheral neuropathies affecting motor and sensory neurons. More than 80 causative genes have been reported as autosomal dominant, autosomal recessive, and X-linked forms –3. The dal genes . GDAP1 is identified as a CMT-causative gene [GDAP1 (Ganglioside-induced differentiation-associated-protein 1) is an integral membrane protein of the outer mitochondrial membrane with a ubiquitous tissue distribution but predominantly expressed in neurons. It is involved in many aspects of mitochondrial morphology and functioning, such as on the maintenance and regulation of normal functioning, structural integrity, and intracellular networking of the mitochondria . GDAP1 iive gene , 8 and iive gene , an axonive gene , an inteive gene , and a live gene –13.GDAP1 autosomal recessive inherited mutations cause a severe, early onset neuropathy often resulting in wheelchair-dependency in the second or third decade. Most of these patients develop unilateral or bilateral vocal cord paresis and diaphragmatic weakness in the latter stages of the disease [ disease . It has  disease . Otherwi disease , 17. GDAP1 gene. This novel variant induces a premature stop codon and may contribute to severe loss of function GDAP1.We herein report the clinical and electrophysiological findings of affected patients in a Vietnamese family with a severe autosomal recessive axonal sensorimotor neuropathy, due to a duplication of 5 nucleotides in coding region of the GDAP1 variants. The 6 exons of GDAP1 were amplified by polymerase chain reaction and analyzed by direct sequencing on an ABI3130XL Genetic Analyzer system . Primers for PCR and sequencing reactions were listed in Supplementary MPZ, GJB1, MFN2, NEFL, and PMP22) have been analyzed as well.We studied a Vietnamese family encompassing all three affected children. The proband and her family underwent clinical and electrodiagnostic evaluations. Genomic DNA was extracted from peripheral blood mainly of the proband and family members using a QIAGEN Blood kit according to the manufacturer's instructions and testing for GDAP1 gene, 50 unrelated healthy Vietnamese control participants were screened. The variant was numbered according to the Human Genome Variation Society (HGVS) nomenclature on the basis of standard reference sequences of mRNA (NM_018972.2) and protein (NP_061845.2).For the new variant inWe described symptoms of the proband and her siblings, ranging in age from 3 to 16 years, and their mean onset age was 27 months.The proband (II-1) had difficulty running starting at 27 months. She was able to independently climb stairs until age 7 and then required ankle foot orthosis at the same year. Due to progressive distal and proximal leg weakness, she needed crutches from age of 10 years. Clinical examination at the age of 16 years showed atrophy of lower legs, lower arms, intrinsic hand muscles, and areflexia. The proximal extremities muscles showed a moderate paresis. There was severe weakness of the lower arm muscles, in particular of the hand muscles. Sensory impairments were not identical in upper and lower extremities: asymmetrical loss of touch and pain sensations with the upper extremities were intact, and vibration was absent in distal. Pes cavus was seen . There wThe 12-year-old sister (II-2) and 3-year-old brother (II-3) of the proband were affected, showing the same symptoms as the proband, although to a lesser extent. Both parents (I-1 and I-2) showed no abnormalities on neurological examination and nerve conduction studies .Nerve conduction studies of the proband showed no CMAP or sensory nerve amplitude potential (SNAP), which suggested axonal neuropathy. EMG showed signs of de- and reinnervation in the right anterior tibial muscle. In the brother of the proband, CMAP reduces significantly and MNCV was in normal range . These d GDAP1 gene in the proband and her two siblings: c.667_671dup, and a heterozygosity of the c.667_671dup in both parents , a C-proximal hydrophobic domain (HD1) crucial for GDAP1-induced mitochondrial and peroxisomal fission, and a C-terminal transmembrane domain (TMD) essential for the correct locating of the GDAP1 protein [ GDAP1 transcripts [GDAP1 belongs to the subfamily of glutathione-S-transferase (GST). It is composed of two typical GST domains (GST-N and GST-C), two alpha helical loops , followed by an addition of 37 amino acids and a premature stop codon. We consider this variant very likely pathogenic since GST-C domain has important roles in the protein function, and the premature stop codon inducing a truncated protein may impair some involving processes. Furthermore, DNA-testing revealed no mutations in other common CMT genes and no similar variation is detected in healthy control group. This case illustrates the challenges in elucidating the genetic cause in CMT families as GDAP1-CMT diseases.This work broadens the genetic spectrum of CMT associated with GDAP1 mutations with the identification of new G224Hfs∗37 alteration and emphasizes the importance of clinical clues in the diagnosis of inherited neuropathies. It is possible that there are many factors contributing and modulating the GDAP1-CMT and each of the mutations turns the disease in different way, affecting some processes more and some less, thereby explaining such diverse course and severity of CMT disease. More comprehensive information of the genetic background of CMT disease in the Vietnamese is needed in order to describe and understand the effects of mutation on clinical course and prognosis, elucidate the correlation between the genotypes and the clinical phenotypes, and determine the attribution of certain geographical distribution, ethnic background, and areas of high consanguinity.