Proliferative vitreoretinopathy (PVR) is the leading cause of failed rhegmatogenous retinal detachment (RRD) surgery. Based upon the presence of clinical features and due to associated underlying risk factors, it is classified into various grades based upon its severity and extent of involvement. Despite excellent skills, flawless techniques, and high-end technology applied in the management of RRD, PVR still occurs in 5–10% of cases. Due to the advancements in wide angle viewing systems, advance vitrectomy machines and fluidics, early identification, use of long-term heavy silicon oil tamponades, high-speed cutters, small-gauge vitrectomies, use of perfluorocarbon liquid (PFCL), and small-gauge forceps and scissors, the success rate in the management of PVR has increased leading to improved anatomical outcomes. However, functional outcomes do not correlate well with improved anatomical outcomes. Various complications occur after RRD repair that are responsible for re-retinal detachment and recurrence of PVR. This article highlights causes, risk factors, classification, grading, diagnosis, and approach to management of PVR and post-PVR surgery complications. In 1983, on the basis of “massive vitreous traction” or “massive periretinal proliferation,” the Retina Society Terminology Committee put forward a classification and Proliferative Vitreoretinopathy (PVR) was identified as an independent clinical entity . It leadPVR develops through a very complex process that involves humoral and cellular factors. The retinal pigment epithelial (RPE) cells, glial cells, fibroblasts, and macrophages act as nidus for its pathogenesis . The varPVR may be present spontaneously with primary retinal detachment or may develop even after retinal detachment surgery . VariousInitially preretinal PVR adopts an immature appearance and consistency. Later on, by 6 to 8 weeks, the membrane becomes more mature, taking on a white, fibrotic appearance. In this stage, PVR can be easily seen clinically and causes retina to become stiff and immobile , 29. TheVarious tools in the form of slit lamp biomicroscopy and indirect ophthalmoscopy along with the use of various lenses in eyes with clear media and using B-scan in cases of opaque media help in the diagnosis of PVR along with various risk factors. It helps in meticulous planning of surgical approach. Early intervention is better as PVR often leads to substantial vision loss and a poor visual outcome.In 1983, PVR as a significant clinical entity was noted and a classification for grading of PVR was put forward by the Retina Society Terminology Committee –32. It wThe most important aspect to prevent development of PVR is the early identification of various risk factors that are held responsible. The key feature is to pick up early various subtle signs and along with increased awareness that can help surgeon to modify the plan of management thus helping to prevent this serious complication. If early PVR is noted, it is better to proceed with combined scleral buckling and vitrectomy rather than a single procedure of the two, along with the use of long-term heavy silicon oil tamponades.Broadly PVR can be divided into two groups: (1) preexisting with rhegmatogenous retinal detachment (RRD). This is seen usually with long standing RRDs. (2) PVRs that occur after primary surgery for RRDs: this usually occurs after a period of 4–6 weeks of initial surgery. Initially retina seems attached with some visual gain which later tends to deteriorate with the development of PVR. During examination, PVR is identified by retinal traction caused by retinal membranes. In most of the cases of PVR, inferior retina is affected more due to gravity-based deposition of RPE cells. Vitreous haze along with the release of pigment cells in vitreous cavity and over the surface of retina can be seen. Posterior PVR is detected by starfolds with folds radiating from a central area of contracted retina, and more diffuse folds and later on subretinal membranes are also seen beneath the retina. These folds may even take an annular configuration pulling the retina over the optic disc . MembranDiagnosis of the presence of PVR and its grading based on available classification systems is done with the help of indirect ophthalmoscopy examination with +20D lens. A thorough examination of retina is conducted and grading of PVR is done with the aid of retinal drawing. This can be done in presence of clear media allowing clear view of retina. However, in presence of media opacity obscuring view of retina and henceforth, disabling retinal examination, B-scan is the preferred diagnostic tool. Examiner asks patients to move their eyes while performing B-scan to identify the mobility of detached retina. In the absence of PVR, in a case of RRD, the retina has good mobility on B-scan. In a case of RRD with PVR, the flaps of the retina may assume a “V” pattern at the optic disc with very limited retinal mobility as they approach the optic nerve  . With moThe mainstay for management of PVR is surgical intervention. With the evolution of surgical techniques, better instruments, fluidics, facilities, wide angle viewing systems, small-gauge vitrectomies, and heavier silicon oil tamponades, there is a significant rise in success rate of PVR surgeries. PVR may present with single clinical feature or multiple features in different cases. There may be only a starfold at a single location, fixed membranes leading to funnel shaped retina, immobility of retina, contraction, and retinal stiffening and shortening. The main goal of management is to relieve the traction and to reattach the retina. However, in cases with severe PVR, additional maneuvers are required to relieve traction in order to reattach the retina and prevent redetachment , 7, 35. Although vitrectomy with removal of entire remnant vitreous, posterior hyaloid, and fibrinous and cellular elements causing traction is the core concept in management of PVR, scleral buckling also has a significant role when treating PVR detachments. Scleral buckles relieve both anteroposterior traction and circumferential traction. In a case of RRD with PVR, encircling bands that support the entire vitreous base are more useful than segmental elements and are frequently used along with PPV . HoweverMany surgeons believe and have also published in literature that vitrectomy along with silicon oil is enough for the management of PVR . HoweverFor PVR surgery, either local or general anesthesia is acceptable. However, owing to prolonged duration of surgery, also based on type and grade of PVR, present and various other patient related factors, and the comfort of the surgeon and the patient, the type of anesthesia is decided as per case.After a thorough meticulous examination, the severity and stage of PVR are judged, and the approach is planned. The approach consisting of combined scleral buckle with vitrectomy gives more effective outcomes. If a scleral buckle is planned, conjunctiva is opened by limbal peritomy and an encircling 360° scleral buckle is put . UsuallyOne should definitely try that natural lens should be preserved. The natural lens always tends to become cataractous with silicon oil and later can be comfortably removed as a separate procedure or during a combined sitting with silicon oil removal. But, if the cataract is significant enough obscuring the view during retina surgery, it needs to be removed along with retina surgery. Removal of lens along with retina surgery also allows good and thorough shaving of vitreous base. Lens can be removed either by phacoemulsification/small incision cataract surgery of pars plana lensectomy with or without IOL implantation based upon the situation . One musAfter dealing with lens and obtaining a clear view of retina, meticulous removal of vitreous is done along with the removal of posterior hyaloid. Intravitreal injection of triamcinolone acetonide helps in identification of vitreous to avoid any remnant vitreous and posterior hyaloid . 23-gaugOnce the vitreous is removed, it is extremely important to remove all folds, wrinkling, and contraction by identifying the membranes that are responsible for causing them which can be facilitated by using brilliant blue dye (BBD). BBD helps to stain the membranes that can be peeled by forceps or trimmed with cutter as per situation. It is very important to identify all membranes and to remove them all, to enable retina to become mobile again . Due carIn long-standing PVRs, subretinal bands are noted that prevent retinal flattening even after meticulous removal of all preretinal and retinal surface membranes. This warrants the need of a small retinectomy and removal of these bands assisted with forceps. Once all subretinal bands are removed and even after that retina fails to flatten due to severe contraction or shortening owing to chronicity or long-standing contraction, then retinectomy is needed to achieve retinal flattening. Small-gauge soft tip cannulas are inserted into retinectomies or breaks and subretinal fluid is aspirated by active suction along with fluid-air exchange enabling the surgeon to achieve retinal flattening –50.After retinal flattening, chorioretinal apposition is needed which is done by a good endolaser photocoagulation around all the breaks, retinotomies, and retinectomies followed up at 360° endolaser barrage around the peripheral retina . ExcessiOnce all breaks are sealed with laser, next step involves the use of a tamponade. Although both gas and silicon oil can be used as tamponading agents, out of both, silicon oil provides long-term and more adequate tamponade in PVRs. Literature suggests that most surgeons prefer silicon oil as tamponade in the management of PVR. The use of gas is associated with restricted air travel and risk of ocular hypertension and an inadequate tamponade leading to more chances of recurrence , 52. SomVarious less viscous forms of standard silicon oil are available like 1000, 1300, and 1500 cSt (centistokes). Slightly more viscous form 5000 cSt is also available. Few surgeons prefer less viscous form and few surgeons more viscous form. However, if the breaks are not well closed and residual traction is still present, the oil of any viscosity will seep through and enter into subretinal space through open breaks. The standard silicon oils are lighter than water.Standard silicon oils fail to provide perfect apposition between oil bubble and peripheral inferior retina causing a gap, which can get filled with proliferating residual cells and debris and leading to recurrence more commonly involving inferior retina. This condition can be avoided by use of heavy fluorinated silicon oil which provides a better tamponade particularly after inferior relaxing retinectomy. However, long-term retention side effects of heavy fluorinated silicon oil are yet known, so they are preferably removed within a time frame of 3 months –66. OnceUsually within an interval of 3 to 6 months based on various factors along with scar maturity, silicon oil removal is done. Long-term retention may lead to certain unwanted complications. However, after silicon oil removal, there is a significant risk of retinal redetachment . DespitePostoperative prone positioning is advised for approximately 10 hours a day for the first 1 week, which can later be reduced to 4–6 hours/day for the next 3 weeks. The idea behind this is to egress out any residual subretinal fluid by retinal pigment epithelium pump mechanism and to promote chorioretinal adhesion leading to retinal scar formation at the site of laser. Postoperative intraocular pressure rise can be seen which needs immediate intervention by oral and topical antiglaucoma medications to avoid any damage to optic nerve and associated pain. Most common cause of raised intraocular pressure is the overfill of silicon oil and at times if medications fail to bring down pressure to a desired value, then a small volume of oil needs to be aspirated out surgically. The cycloplegics, antibiotics, and anti-inflammatory drugs keep a check on postoperative infection and inflammation.Management of PVR is complex and even after a successful retinal attachment complications can occur and patients along with relatives need to be informed along with a written informed consent preoperatively about possible complications. Some intraoperative complications that can occur include bleeding, corneal edema, pupillary constriction, lens clouding, subretinal migration of PFCL and/or oil, gas, choroidal detachment, and choroidal bleeding. Intraoperative bleeding during surgery can be managed by raising the infusion pressure or by applying cautery at the site of bleeding for few minutes to allow clot formation and bleeding to stop. Corneal edema or opacification can develop due to prolonged contact of viscous material and needs epithelial debridement allowing clear visualization during surgery. Pupillary constriction can be managed by use of intraoperative intracameral use of dilating agents or cutting the synechiae or membrane, which is causing obscuration of view. Lens clouding or opacification due to a preexisting significant cataract or due to intraoperative lens touch needs lensectomy or a planned cataract surgery by phacoemulsification or small incision cataract surgery with or without IOL implantation. Subretinal migration of PFCL or oil needs to be approached by making a small meticulous retinotomy and drainage. Choroidal detachment usually happens due to wrong placement of cannula into suprachoroidal space and is managed by securing infusion line through a separate cannula and reinserting misplaced cannula into vitreous cavity.A close followup is vital as immediate postoperative complications include ocular hypertension, pupillary block glaucoma, shallowing and closure of the anterior chamber, intraocular inflammation, subretinal hemorrhage, and silicon oil in the anterior chamber. Ocular hypertension needs immediate intervention with anti-glaucoma medications. If medical management fails to lower the intraocular pressure, it usually happens due to silicon oil overfill and some amount of oil needs to be extruded to maintain the desired pressure level. Other complications also may need immediate surgical intervention if causing pain and raised intraocular pressure as they may vision threatening and may lead to permanent vision loss.Late complications of PVR surgery include regrowth of membranes causing traction, opening of old breaks, formation of new breaks, recurrent retinal detachment , glaucomOver the past few decades with advancement in techniques, instrumentation, and machines, the success ratio in anatomical management of PVR has increased a lot. Still, many eyes undergo redetachment that requires resurgery. Once macula is detached for more than few days, it is unlikely to recover more than 10–20% of central vision. Henceforth, anatomical success in terms of successful retinal attachment for a period of 6 months cannot be compared as equivalent to functional success [PVR is the leading cause for failure of RRD repair and is identified by the growth and contraction of cellular membranes within the vitreous cavity and on both sides of the retinal surface leading to retinal contraction and fixed starfold formation. Various risk factors have been identified that lead to PVR formation. Despite the best of machines, advances in techniques, instrumentation, and the increased success rate in terms of anatomical reattachment, the real meaningful long-term stable successful visual outcome is yet not achieved and many eyes in long course tend to suffer severe vision loss. Medical therapy is also tried but to date no real success. However, we may hope that, with the continual advancements in techniques and technology going on, some way of restoring long-term meaningful visual potential may soon arrive in the medical world.


The objective of this study was to investigate the auditory pathway maturation monitored by auditory brainstem responses (ABR) in infants with hearing loss during the first year of life. ABR were used to estimate hearing thresholds and the effect of early intervention strategies using hearing aids (HA).Click-evoked ABRs were measured in 102 infants aged from 0 to 12 months to determine their individual auditory threshold. Early therapy intervention was recommended before 12 months of age and analyzed. To evaluate the effect of hearing amplification on auditory maturation, different subgroups of infants with moderate hearing loss were analyzed and the auditory pathway maturation was determined based on IPL I–V shortening.Overall, 110 ears (54.0% of 204 ears) with mild to profound HL showed threshold changes of 10 dB up to 60 dB in the follow-up ABR testing. HA were prescribed at the age of 3.8 ± 3.9 months. Cochlear implantation (CI) was performed in cases of repeated profound HL at the age of 9.9 months ± 4.5 months. A significant shortening of IPL I–V in all subgroups of infants (with and without risk factors) who received HA was shown and assumed auditory pathway maturation.An early intervention using optimally fitted HA influenced auditory pathway maturation and may lead to improvements of hearing thresholds during the first year of life in infants. This study underscores the importance of not only providing HAs to infants, but also controlling for hearing threshold changes ensuring that HAs provide the optimal level of intervention or CI is indicated. Severe to profound bilateral sensorineural hearing loss (SNHL) is present in 1 to 3 out of 1000 newborns and 2 to 4 out of 100 infants who require neonatal intensive care (American Academy of Pediatrics 1999) , 6. In c. The click-evoked ABR provides reliable estimates of the behavioral pure-tone thresholds in the frequency range 2–4 kilohertz (kHz). Using special fitting and stimulus configurations, more frequency-specific responses down to 1 kHz can be evoked [The ability to obtain reliable behavioral responses in infants is useful clinically . Even the evoked , 16.The central auditory system is immature at birth. The main neuronal maturation occurs within the first 2 years of life , 11, 17.. These risk factors include family history of HL, in utero infections, craniofacial anomalies, diagnosis of a HL-associated syndrome, postnatal infections and head traumata [Certain risk factors have been associated with HL in children , 20 and traumata . Perinattraumata . Severe traumata . All infThe possibility of hearing threshold changes in infants as described in numerous previous studies on follow-up ABR measurements draws attention to the need of clear discrimination of the HL type at the time of diagnostic testing as well as the performance of follow-up ABR testing of diagnosed SNHL . In a stThis current ABR study was aimed at investigating the auditory threshold changes and auditory pathway maturation within the first year of life. The effects of early therapy based on the results of the ABR measurement were evaluated and the reliability of AEPs as a tool for early examination of auditory pathway maturation leading to treatment indications during the first year of life was investigated.We retrospectively reviewed the medical records of 102 infants who were referred to a tertiary care hospital between March 2012 and March 2019 and received two or more ABR measurements within the first year of life. The study group consisted of 33 female and 69 male, 18 premature and 84 full-term infants, and 29 infants (28.4%) that were identified to have risk factors that are listed in Table ABR measurement  was performed during postprandial natural sleep. For ABR recordings, a click was used , the stimulation rate was 19.1 Hz, and 2000 averages were used and delivered through a pair of TDH-39P audiometric earphones . The latency and amplitude of wave Jewett I, wave Jewett V and IPL I–V were registered and compared to norm values for the age groups when anatomically possible in case delayed auditory maturation depended on the prolonged latency of IPL I–VRecommendations for determining HA use:For parents, it is an essential foundation to be provided with complete information to help them resolve barriers to effective daily management and acquire support for skill acquisition. Therefore, they were supported from early intervention programs either home based or center based to learn to navigate challenges with HA fitting of their infants more effectively.Follow-up ABR testing was conducted within 1 to 3 months to investigate changes in hearing thresholds, review the current therapy, and if necessary indicate further treatment. If a gradual progression of the HL was recognized in the ABR measurements up to the first year of life, we followed all further measurements of the infants.HA were provided at a median age of 3.4 months ± 2.6 months for the right ear and at a median age of 4.1 months ± 5.2 months for the left ear. The infants were provided with HA at all degrees of HL. In total, 10 ears with mild HL (five right ears and five left ears), 47 with a moderate HL (22 right and 25 left ears), 9 with a severe HL (seven right and two left ears) and 29 ears with a profound HL (15 right ears and 14 left ears) were equipped with HA. In the follow-up consultations, the parents reported that the infants had accepted the use of the HA devices and showed good acceptance.To analyze the effect of the hearing amplification on the auditory maturation, we looked at two different subgroups of infants with moderate HL. In the majority (68%) of the ABR measurements of the infants with moderate HL, wave Jewett I and wave Jewett V were identified that allowed the assessment of IPL I–V.The first subgroup was composed of all infants with moderate HL separated into right and left ears and HA users and non-HA users.In the second subgroup, we further looked at infants with identified risk factors with moderate HL (only those in whom the determination of IPL I–V was possible) provided with HA and separated them from infants fitted with HA without risk factors to identify if risk factors possibly affect auditory maturation.® Office Excel 2010. Results were analyzed and plotted in a custom-written Matlab 2017a . As a criterion of significance, a 95% confidence level (p < 0.05) in the Student ‘s t test was considered as significant.The data obtained were organized into tables and figures, using descriptive statistics with MicrosoftEthic approval is pronounced positively from MHH-Ethics committee.Fifty-eight infants (56.9%) showed threshold changes in the follow-up testing on the right ear and 51 infants (50.0%) on the left ear. An improvement was recognized in 50 right ears (49.0%) and 41 left ears (40.2%) and deterioration in eight right ears (7.8%) and ten left ears (9.8%). By how much dB the hearing threshold changed depending on the severity of the HL and treatment with HA between the first and last ABR measurements is summarized in Table No hearing threshold change was seen in 43 right ears (42.2%) and 51 left ears (50.0%) in the follow-up ABR testing. Despite no apparent change in thresholds, a reduction of the IPL I–V was seen in the infants with mild-to-moderate HL on both sides. 29 right ears and 34 left ears were diagnosed with a profound HL in the initial ABR measurement and the IPL I–V could not be measured. Twenty-four right ears and 22 left ears with a profound HL at the time of the repeated ABR measurement were provided with CI (at a minimum age of five months). In preparation for a CI surgery, a detailed audiological and radiological diagnostic using computer tomography (CT) and magnetic resonance tomography (MRT) of the temporal bones was carried out under general anesthesia. CI was performed at the age of 9.3 months ± 4.0 months on the right ear and at the age of 10.4 months ± 4.5 months on the left ear.A progression in HL was recorded in 19 ears (9.3% of 204 ears)  who received HA assumed auditory pathway maturation Figs , 3. Our In a study of Moreno-Aquirre et al. with 13 infants with perinatal brain injury and severe to profound HL, threshold changes were also determined after the early use of HA on the right ear with the left ear being the control side before the age of 6 months . In theiGiving the retrospective nature of this study, we can only speculate whether these improvements of hearing levels may have occurred without an early use of HA. Evaluating the effect of hearing amplification would need a larger prospective case–control study, but such a study would encounter other ethical challenges pertaining to treatment delivery.In the groups of non-HA users, we investigated decreasing latencies of Jewett V and major improvements of thresholds (in most cases 30–40 dB). Both facts indicate that middle ear effusion might have been the reason for the delayed wave Jewett V and the hearing threshold at the time of the first evaluation. Considering the incidence of middle ear effusions in infancy under the age of 2 years is estimated to be as high as 61% , 24, 33.The incidence of progressive HL in children has been reported with an extremely wide range of 4% to 30% in the literature . A studyFurthermore, in case of a progressive HL, an early diagnosis achieved by appropriate diagnostic investigations including MRI and CT imaging and detailed genetic analyses is necessary. In this study, CT imaging showcased the etiology of progressive HL in three cases . In three cases of progressive HL, the infants showed normalization in hearing in the follow-up ABR measurements after the first year of life. In another six cases, the hearing threshold remained stable after the first impairment and the children showed a good acceptance of the HA.Taking all the cases into account that showed a change of the hearing threshold in this study—improvement or deterioration—we underline the importance of auditory monitoring of infants using AEPs before the first year of life. Identifying the hearing impairment within the first months of age and starting with HA as first-line therapy leads also to an adequate diagnostic procedure and threshold confirmation towards the indication for CI. The confirmation of the hearing level at an age of 6 months helped the infants in our study to receive CI after auditory stimulation at a median age of 9.8 months for the right ear and 11.5 months for the left ear. Lammers et al. reported in 2015 that the median age at implantation decreased significantly because of effectively performed NHS. Over the period from 1995 to 2001, in the center UMC Utrecht and our ENT center, it decreased from 3.4 years to 0.9 years, and 3.1 years to 1.9 years, respectively . This stThe results of this study also have implications for introducing national NHS tracking in Germany as a consequence of the first part of NHS. This tracking is not only responsible for the quality of identifying the potential hearing-impaired subjects within the first screening 4 days after birth. The second important goal is to ensure the diagnostic procedure and the initiation of the HA therapy. In some countries such as Netherlands, USA and Oman, a tracking system is organized by the insurance companies or the government. Children with a repeated negative hearing screening are referred to an audiology clinic by the screening system. The duties of the NHS tracking are to recommend confirmation of diagnosis and monitor whether it is performed and if therapeutic action takes place. Results from the national tracking system in Netherlands showed that in 2011, 50% of the children with suspected hearing impairment were referred within the desired standard of 24 days .In conclusion, auditory function in infants can improve after early acoustic stimulation with HA, paralleled by an increase in the hearing threshold based on ABR measurements. Furthermore, the auditory maturation can be detected at the age of 6 months or even earlier. The ABR results support diagnosis, timely initiation of therapy and therapy adjustments. The staged additional hearing testing of infants is essential to monitor the development of the hearing level at a very early age using repeated ABR measurements Fig.  not only


Gastroenteropancreatic neuroendocrine tumors (GEP-NET) account for roughly 60% of all neuroendocrine tumors, and low/intermediate grade human GEP-NETs have relatively slow growth rates that many laboratory culture methods fail to capture. Patient-derived cancer organoids (PDCOs) are an attractive model to address this need for relevant 3D cultures of GEP-NETs for laboratory drug testing. However, traditional measurements of drug response are not effective in GEP-NET PDCOs due to the small volume of tissue and slow growth rates that are characteristic of the disease. Here, we test a label-free, non-destructive optical metabolic imaging (OMI) method to measure drug response in live GEP-NET PDCOs. OMI measured a response to the novel treatment combination of ABT-263 and everolimus in five out of seven PDCO lines, at 72 h post-treatment. Overall, this work shows that OMI provides single-cell metabolic measurements of drug response in PDCOs to guide drug development for GEP-NET patients.Gastroenteropancreatic neuroendocrine tumors (GEP-NET) account for roughly 60% of all neuroendocrine tumors. Low/intermediate grade human GEP-NETs have relatively low proliferation rates that animal models and cell lines fail to recapitulate. Short-term patient-derived cancer organoids (PDCOs) are a 3D model system that holds great promise for recapitulating well-differentiated human GEP-NETs. However, traditional measurements of drug response  are not effective in GEP-NET PDCOs due to the small volume of tissue and low proliferation rates that are characteristic of the disease. Here, we test a label-free, non-destructive optical metabolic imaging (OMI) method to measure drug response in live GEP-NET PDCOs. OMI captures the fluorescence lifetime and intensity of endogenous metabolic cofactors NAD(P)H and FAD. OMI has previously provided accurate predictions of drug response on a single cell level in other cancer types, but this is the first study to apply OMI to GEP-NETs. OMI tested the response to novel drug combination on GEP-NET PDCOs, specifically ABT263 (navitoclax), a Bcl-2 family inhibitor, and everolimus, a standard GEP-NET treatment that inhibits mTOR. Treatment response to ABT263, everolimus, and the combination were tested in GEP-NET PDCO lines derived from seven patients, using two-photon OMI. OMI measured a response to the combination treatment in 5 PDCO lines, at 72 h post-treatment. In one of the non-responsive PDCO lines, heterogeneous response was identified with two distinct subpopulations of cell metabolism. Overall, this work shows that OMI provides single-cell metabolic measurements of drug response in PDCOs to guide drug development for GEP-NET patients. Gastroenteropancreatic neuroendocrine tumor (GEP-NET) incidence and prevalence have increased 6-fold over the last 30 years . This elProposed mechanisms of resistance to mTOR inhibitors include compensatory activation of other oncogenic pathways and upstream activation of the PIK3CA-AKT-mTOR pathway . ImportaPre-clinical drug screens are difficult to perform for GEP-NETs because there are currently no readily available cell lines or animal models that reliably recapitulate well-differentiated human GEP-NETs. These challenges in pre-clinical modeling are due to the relatively low proliferation of human GEP-NETs ,12, the m) is the weighted average of the short and long lifetimes  from the bi-exponential fit. The optical redox ratio, along with NAD(P)H and FAD τm, provide complementary information that can be used to interpret the metabolic state of cells [m, FAD τm) can be linearly combined  to form a composite OMI index. The OMI index is a metabolic measure of drug response that precedes changes in cell viability or tumor size [m, and increased FAD τm. This leads to a decrease in the OMI index (OMI index = redox ratio + NAD(P)H τm − FAD τm) with drug treatment in responsive cells [The small volume of tissue and a slow proliferation rate of GEP-NET PDCOs limits the relevance of standard measurements of PDCO drug response , which rely on accelerated growth and often require sample destruction. Therefore, metabolic imaging methods are attractive to monitor treatment response in GEP-NET PDCOs. Previous imaging-based studies have investigated cell metabolism in 3D PDCO cultures with optical probes that measure intracellular oxygen , glucoseof cells . The OMImor size . Generalmor size  resultinve cells . Additiove cells  while chve cells  and glutve cells . Previouve cells ,35,36. HSTC-1 mouse neuroendocrine cells (ATCC) were cultured in DMEM + 10% FBS + 1% Pen-Strep. A dose response curve was performed using a 96 well plate WST-1 assay to determine the proper dose of everolimus (range: 0.1 nM–5 nM) as the cells are a mouse line, grown in 2D, and cell lines have previously been shown to be more sensitive to everolimus . Imaging2. Depending on initial sample size, the sample was incubated a minimum of 5 min and a maximum of 2.5 h until roughly 80% of the tissue was digested. For longer digests, the sample was removed from the incubator and repetitively shaken in 10–20 min intervals. After digestion, the samples were pipetted vigorously to break them up further, spun at 1000 rpm for 5 min, and the pellets produced were washed with cold sterile 1× PBS to remove any residual digestion buffer. Finally, the PBS was aspirated, and the pellet resuspended in ADFstock (DMEM/F12 + 1% pen-strep + 5 mL 100× Glutamax + 5 mL HEPES). The cell suspension was mixed 1:1 with 50 µL of cold Matrigel and 50 µL of Matrigel/cell mixture was pipetted into each well of a pre-warmed 24-well plate. Dishes were incubated for 2–5 min at 37 °C to allow the Matrigel to solidify, then plates were flipped upside-down and incubated for at least 20 min at 37 °C. This allowed the Matrigel to form a hanging drop in which the PDCOs could grow three-dimensionally. After incubation, plates were flipped right side-up and the droplets covered with ADFfeed (10 mL ADFstock + 10 µL EGF) before being returned to the incubator. PDCOs were fed with fresh ADFfeed every 2–3 days. All studies involving human tissue were performed with approval from the University of Wisconsin-Madison Institutional Review Board with informed consent from patients. Human tissue from needle biopsy or surgical resection was placed immediately into chilled chelation buffer and placed on ice for up to one hour for transportation from the hospital. The sample was then washed twice by dipping in culture medium, Advanced DMEM/F12  containing 10% fetal bovine serum and 1% pen-strep. The sample was then placed in digestion buffer (5 mL culture medium + 100 µL collagenase + 62.5 µL dispase) and shaken vigorously before incubation at 37 °C and 5% COPDCOs were re-plated 1–2 times after initial culture of 2–4 weeks and maintained in culture for at least one month to ensure viability prior to in vitro assays. PDCOs were re-plated by removing medium and fresh cold medium was used to break up the Matrigel and collect the spheres. If sphere number was low, spheres were pelleted. Spheres were then combined in a 1:1 mixture with fresh Matrigel and plated. GEP-NET tumors are characterized by slow growth, so our methods aimed to maintain this slow growth for clinical relevance. Therefore, PDCOs were re-plated, not passaged, as they do not proliferate enough to repopulate new dishes. The goal of re-plating was to transfer the PDCOs to fresh Matrigel and onto imaging dishes to perform the studies, not to passage cultures to increase the number of PDCOs. GEP-NET PDCOs were maintained in culture for 1–2 months in these studies. The low proliferation rate and loss of material with re-plating limits longer term culture of GEP-NET PDCOs. Additionally, the low proliferation rate of the GEP-NET PDCOs resulted in poor recovery from freezing, and we were not successful with cryopreservation of these lines.p > 0.05).PDCOs were plated in 24-well culture plates and allowed to grow for one day. Images were taken on a Nikon Ti-S inverted microscope using a 4× objective (day 1). After imaging, PDCOs were fed and allowed to grow for an additional six days. Day 7 images were acquired, followed by additional feeding and growth for 7 more days, at which point day 14 images were acquired. The images were analyzed using ImageJ to determine the relative change in median organoid diameter. All experiments were completed in triplicate, and the number of organoids measured per patient ranged from 13–101 . There w5 photons/second to ensure adequate photon observations for lifetime decay fits, and no photobleaching. The instrument response function was measured from second harmonic generation of urea crystals excited at 900 nm, and the full width at half maximum (FWHM) was calculated to be 220 ps. A Fluoresbrite YG microsphere  was imaged as a daily standard for fluorescence lifetime. The lifetime decay curves were fit to a single exponential decay and the fluorescence lifetime was measured to be 2.1 ns (n = 7), which is consistent with published values [PDCOs grew four days prior to treatment. There is some difference in the organoid diameter between patient samples at beginning of treatment, but all PDCOs had a diameter of less than 200 mm. For treatment, the regular media were replaced with media containing physiologically relevant doses of the different treatments (250 nM ABT263 and 200 nM everolimus) ,39,40,41d values ,42.1 × exp(−t/τ1) + α2 × exp(−t/τ2) + C. In this model, I(t) is the fluorescence intensity at time t after the laser excitation pulse, α represents the fractional contribution from each component, C accounts for background light, and τ represents the fluorescence lifetime of each component [m) of both NAD(P)H and FAD were calculated as τm = α1τ1 + α2τ2. The total intensity was calculated from the lifetime data by summing the photons detected at each pixel in the image. The intensity of NAD(P)H was then divided by the intensity of FAD for each pixel to calculate the optical redox ratio. NAD(P)H and FAD fluorescence lifetime images were analyzed using SPCImage software  as previously described . At eachomponent ,43. A twomponent ,28. The m, τ1, τ2, α1, and intensity of NAD(P)H and FAD, as well as the optical redox ratio, were measured for each cell cytoplasm. These data were used to calculate the OMI index for each cell using a linear combination of the normalized redox ratio, NAD(P)H τm, and FAD τm, with coefficients of , respectively. For each variable, values for all cells within a treatment group within a patient were pooled together, the mean and 95% confidence interval for each OMI variable are reported in As previously described, an automated cell segmentation pipeline was created in Cell Profiler  and applOver 100 cells per patient per treatment condition are required for robust estimation of cell sub-populations , and thri represents each subpopulation, d represents the distance between the median of each subpopulation and the median of the entire distribution, p represents the proportion of all cells belonging to that subpopulation, and σ is the standard deviation of the subpopulation. The heterogeneity index was previously validated to predict tumor response in vivo and in tumor organoids . Here wep-value < 0.05 defined as significant. Treatment effect size was calculated using Glass’s Δ [Differences in OMI index between treatment and control organoids were tested using a one-way ANOVA of control vs. treatment, with a lass’s Δ ,51. Glaslass’s Δ ,49. PDCOs were re-plated 1–2 times and maintained in culture for at least one month before plating on glass 22 mm circular coverslips for histologic processing and staining. Note that the proliferation rate of these PDCOs was insufficient to repopulate the cultures, so re-plating was used to refresh the cultures. Histologic analysis was not performed at later time points due to the low proliferation rates of the cultures. PDCOs were fixed in 2% paraformaldehyde for 15 min. The paraformaldehyde was removed, and the fixed PDCOs were rinsed in PBS followed by storage in PBS at 4 °C until staining was performed. H&E staining was performed as previously described . BrieflyTissue IHC and IF were performed as previously described  using thSTC-1 cells (mouse NET) were used to determine the effect of ABT263 and everolimus treatment in NET cells using standard measurements of response. Immunofluorescence with DAPI, Ki67, and Cleaved Caspase-3 (CC3), an apoptosis marker, revealed that STC-1 cells have a high baseline proliferation rate of around 40% Ki67 positive cells A,B. ThisThe OMI index significantly decreased in STC-1 cells treated with ABT263 plus everolimus compared to control C, consisPDCOs were generated from surgical specimens or biopsies for all GEP-NET samples . The oveThe histology of the original patient tumors, by H&E staining, was compared to whole mounts of the resulting PDCOs for a subset of patients. In all cases, the organoid cultures were morphologically similar to the tumors from which they were derived, including a similar well-differentiated morphology represented by a monotonous nuclear appearance with “salt and pepper” chromatin characteristic of neuroendocrine tumors A. Both pKi67 is a marker of cell proliferation and the percent of positive Ki67 cells is slightly decreased in the PDCOs compared to the patient tumor B,C, highClinical growth of GEP-NETs is often slow, with samples commonly presenting <20% of cells as Ki-67 positive ,57. ThisGEP-NET PDCOs are metabolically active, as shown by the fluorescence lifetime of NAD(P)H and FAD as well as the redox ratio E, despitPopulation density modeling of single-cell OMI data was used to determine whether subpopulations, defined as single Gaussian distributions, were present in PDCOs for each treatment condition after 72 h . However1, τ2, and τm, as well as an increase in Z-score for NAD(P)H α1  across all treatments, except for the ABT263 and combination treatments for Patient 5. There is greater variability between patients in the Z-scores of FAD lifetime variables, as some patients have a positive Z-score for all treatments while other patients have mostly negative Z-scores . Overall, these full data . These GEP-NET PDCOs maintained proliferation rates similar to the original tumor C along wThis unique combination of GEP-NET PDCOs and OMI was used to test a new drug combination for GEP-NET patients. Here, OMI was collected at 72 h post treatment to maximize differences due to drug treatment . HoweverThis study was not sufficiently powered to robustly address drug synergy but focused on new methods to maintain GEP-NET PDCOs and establish feasibility of drug response measurements with OMI. Further studies are needed to determine whether GEP-NET PDCO response to the combination of ABT263 and everolimus correlates with patient response. However, previous studies from our group using other cancer types (colon and pancreatic) indicate that OMI of PDCO treatment response often predicts later clinical response ,49. AddiIn conclusion, OMI is an attractive label-free tool to measure metabolic changes due to drug treatment in GEP-NET PDCOs. This is an important development because GEP-NETs have low proliferation rates that make standard measurements of treatment response ineffective. This study is the first to use OMI to measure drug response in a PDCO model of GEP-NETs. We have shown that GEP-NETs can grow in 3D PDCO culture and maintain a phenotype that is similar to in vivo patient characteristics. Furthermore, we measured metabolic changes indicative of treatment response in 5 out of 7 PDCO lines with a novel combination therapy of ABT263 and everolimus. These innovative methods for GEP-NET drug screening could streamline drug development for GEP-NET patients, who are in great need of new therapies.


In France 58% of persons with hearing loss still do not wear hearing aids. Pure-tone audiometry is the traditional gold standard in assessment and screening of hearing impairment, but it requires the use of calibrated devices and soundproof booth. The antiphasic digits-in-noise (DIN) test does not require calibrated material and can run on a standard headset or earbuds connected to a smartphone or a computer. The DIN test is highly correlated with pure tone audiometry and has already shown to be effective in hearing loss screening in its English version promoted by the WHO. The aim of the present study was to develop and validate a French version of the antiphasic DIN test for implementation on a national screening test offered as a smartphone app. The audio files recorded from a French native female speaker were selected and normalized in intensity according to their recognition probability. The French DIN test application was then tested on normal hearing- and hearing-impaired subjects. Based on the strong correlation between pure tone audiometry (PTA) and DIN SRT, we calculated ROC curves and Z-score. For PTA > 20 dB HL, a SNR cutoff of 12.9 dB corresponds to a sensitivity and specificity of 0.96 and 0.93, respectively. To detect moderate and more severe hearing loss (PTA > 40 dB HL), the SNR cutoff was −10.9 dB, corresponding to a sensitivity and specificity of 0.99 and 0.83, respectively. The Z-score was calculated to define statistical criteria of normality for speech-in-noise evaluation. While a score of 0 roughly corresponds to the normality (DIN SRT = −15.4 dB SNR), a subject with DIN SRT > −12.2 (Z-score > 2) is ranked in the hearing loss population. Next, the French antiphasic DIN test was implemented in the Höra iOS and Android apps. In total, 19,545 Höra tests were completed and analyzed. Three quarters of them were classified as normal (74 %) and one quarter presented mild (9%) or more severe loss (17%). Together, results argue for the use of the French version of antiphasic DIN test in the general population to improve the screening of hearing-impaired individuals. Hearing loss burden on health and quality of life is often underestimated by public authorities, health care professionals and the public. In the world, hearing loss affects around 20% (1.5 billion people) of the population with an estimated 5.5% (430 million) experiencing significant hearing loss. In France as in other high-income countries, the prevalence is expected to increase rapidly over the next three decades due to an aging population and noise exposure of younger people  has adopted this antiphasic DIN screening approach in the use of their hearWHO smartphone application available in English, Spanish and Mandarin . To dateAccording to Jardé's law regulating biomedical research in France, this type of evaluation is considered as non-interventional research and did not require institutional review board approval. All eligible participants were informed of the study aims and procedures and provided consent before participation.French mono- and bi-syllabic digits (0–9) were selected as speech material. Single-digit recordings were made from a native French female speaker in a sound-proof booth. A carrier sentence “le chiffre” was uttered before pronouncing each digit to allow natural intonation. A microphone (Blue Yeti Microphone) was held ~5 cm from the speakers' mouth during recordings. The speaker was asked to read four lists of randomly ordered digits. Thus, each digit appeared four times. The recordings were digitalized at 44,1 kHz with floating 32 bits resolution using Audacity software (Audacity). Each digit was then cropped manually from the list and stored separately in WAV files using Audacity software. One speech-language therapist and one phonetic academic teacher rated the four recordings of each digit, according to the naturalness, articulation, voice quality, intonation, and speed of production. The final list of digits was compiled using the best rated digits for digits 0–9. The masking noise was generated by shaping a white noise (using FIR filter in Matlab) with the long-term average spectrum of the 10 selected digits . The recDigits were equalized according to their recognition probability. Equalizing digits by applying level corrections to the digits ensured that each digit had a 50% chance of being recognized correctly at the same SNR. To do so, we recruited 20 normal-hearing (both ears) participants aged 20–33 years, with pure-tone thresholds <20 dB HL from 250 to 8,000 Hz. A custom Matlab script was used to generate the sequences of digits superimposed with noise on a laptop (MacBook Pro) that were presented monaurally through circumaural headphones (Sony WH1000XM3). Four lists of 10 digits were successively presented at 10 different SNRs decreasing from −2 to −20 dB in 2 dB steps. For each SNR level the 10 digits were presented randomly. The noise started 500 ms before and finished 500 ms after each digit. The participant was forced to choose a digit, even if it was not recognized (forced-choice procedure). The psychometric curves of recognition for each digit were fitted with a logistic function to determine the speech reception threshold  equipped with a supra-aural TDH39 headphone for air conduction and a bone vibrator B71 for bone conduction. The hearing status was determined according to the pure tone threshold average at 500, 1,000, 2,000, and 4,000 Hz. The normal-hearing participants with PTA ≤ 20 dBHL in both ears were students at the University of Montpellier and of the Institute for Neuroscience of Montpellier, relatives of the authors or accompanying hearing loss people. The participants with hearing loss came from the University Hospital of Montpellier or private clinics.n = 167). The participants (77 women and 90 men) were aged from 19 to 90 years (mean age 56 years of age ±22). The hearing status of the subject was classified according to the recommendation of the International Bureau for Audiophonology (BIAP)  . Among 1DIN test was developed in a webapp working on Google Chrome running on a laptop connected to a commercial headphone (Sony WH 1000 XM3). The selected digits were organized in 120 triplets stored in stereo files. The participants were informed on how to enter the digit responses on the computer keyboard. Before starting the test, they were asked to adjust the loudness of the digit-triplets to a comfortable listening level. The noise was presented in-phase (diotic) in both ears, and the digits were antiphasic between the two ears. The noise was present during the entire digit triplet sequence and started 500 ms before the first digit. Successive digits within a triplet were separated by 200 ms intervals. The initial SNR was fixed at 0 dB and the SNR change was obtained by varying the noise level when the SNR is positive, or by varying the digits level when the SNR is negative . To prevThe French smartphone-based antiphasic digits-in-noise hearing application (Höra) was developed on iOS and Android and is available for free in the Apple store and Google Play Store. The mobile app can be used with standard headphones or earphones. When the application is launched, a tutorial screen appears to inform the subject how to use the application. The subject is instructed to enter a name or nickname (use is fully anonymous), gender and birthdate. Next, the subject is invited to put on the smartphone headset and adjust the intensity of the continuously presented digit-triplets to a comfortable listening level using a scroll bar. When ready, a “Start Test” button allows the subject to begin testing. A pop-up number pad appears after each presentation of the digits to allow the subject to enter his/her responses. A personalized score out of 100 was deduced from the range of SNRs of our reference population. At the end, the subject is categorized as “normal” (score between 70 and 100), “mild” (score between 50 and 70), or “moderate and worse” (score < 50). For “mild” and “moderate” expected hearing loss, the subject is advised to see a doctor.Matlab was used for data processing, statistical analyses and for creating figures. Audiometric data and DIN test data, loaded from the text files generated by the web app, were stored in Microsoft Excel. For each subject, the status of hearing  was determined from the poorer ear PTA of each subject. Pearson correlation coefficient and linear or multilinear regressions were used to assess coevolution of different parameters like age, hearing loss and SNR score of DIN . Receiver operating characteristics (ROC) curves were calculated  to determine the sensitivity and specificity of the DIN tests for different cutoff values, to detect mild hearing loss and worse  and moderate hearing loss and worse (PTA > 40 dB HL). Distribution of results were calculated and fitted with unimodal (one) or bimodal (two) Gaussian models . Gaussian distribution function is y = max ] was used to characterize the time course of PTA or SRT, in which “a” represents the normal hearing, “b” the cut-off age and “c” the slope. All parameters are given with 95% confidence interval. In our reference normative population (n = 167), the mean PTA was 11.6 dB HL (±3.7 dB) until a cut-off age of 40-years of age (±6 years) where the mean thresholds increase at a pace of 1.18 dB/year (±0.18 dB/year). The time course of DIN SRT was similar to PTA (Pure tone average (PTA) of the poorer ear was determined by averaging the thresholds at 0.5, 1, 2, 4 kHz to obtain a single value for each ear and each participant . A broker to PTA  with a mr = 0.82, p < 0.001, Poorer ear PTA was significantly correlated with DIN SRT (n = 30), from which we determined the mean (−15.3 dB SNR) and standard deviation (1.6 dB) of the DIN SRT. The Z-score was calculated to associate a value of normality (p < 0.001) for this subgroup of participants, a Z-score of 1.5 (DIN SRT ≤−12.9 dB SNR) corresponds to the 95th percentile, which is verified with the direct evaluation of percentile on data of the subgroup with exactly −13 dB SNR. In other words, a subject with a DIN SRT of −12.1 dB has a Z-score of 2 , and a subject with a DIN SRT of −10.5 dB has a Z-score of 3 .To establish a reference range of DIN SRT, we selected a population composed of people 25-years of age and normal PTA . Overall, the proportion of male users (55.7 %) was more common than the females (45.3 %). Compared against our reference normative population, the smartphones users were younger . Both populations showed a bimodal gaussian distribution across ages (Z-score between 1.5 and 3) and 20 % had a moderate and worse hearing loss categorization (predicted PTA > 40 dBHL or Z-score > 3) (We subsequently integrated the French antiphasic DIN test in a mobile app (iOS and Android) called Höra. The use of the Höra smartphone app allowed us to reach a large population of subjects  .Our results support the use of the French version of the antiphasic DIN test to detect all hearing losses  with high sensitivity (0.92) and specificity (0.86). We further propose a standard score to compare speech in-noise results to a normal-hearing population.R = 0.82, p < 0.001) and comparable with the English antiphasic DIN test (R = 0.82) (n = 167) is higher (0.82 vs. 0.77), probably because of the antiphasic presentation in our study. These results support the conclusion of Van den Borre et al.  is most likely due to the antiphasic presentation of the digits. This is consistent with the studies of Smits et al. . When DIN SRT was expressed as the function of the poorer ear PTA, the correlation was highly significant ( = 0.82)  using the et al.  suggestie et al. . Therefos et al.  and de Ss et al. , 34 in ws et al. .Based on the strong correlation between PTA and DIN SRT, we calculated ROC curves to determine the best DIN cut-offs predicting hearing impairment. The ROC curve depends on the correlation between the predictor and predicted values. The prediction for a mild hearing loss on the poorer ear according to the international standard (PTA > 25 dB HL) showed a sensitivity and a specificity of 0.96 and 0.93, respectively, compared to 0.95 and 0.73 for the English version . The tesThe French antiphasic DIN test then demonstrates very high quality of hearing loss prediction, but some outliers can be seen, i.e., false negatives and false positives, and may need some explanations. It is important to keep in mind that PTA and DIN test are subject to measurement errors that are potentialized when compared for screening. In our ROC analysis false negatives values correspond to subjects with hearing loss (PTA ≥ 20 dB HL) with a good SRT in noise (DIN SRT < −12.9 dB SNR). This phenomenon can be explained by the antiphasic stimulus presentation, known to improve speech perception in noise for people with well-preserved symmetric low frequencies hearing thresholds . On the Z-score is very useful because it allows calculation of the probability of a score occurring within a normal-hearing population and compare two scores that come from different populations with the normal distribution. In our study, a score of 0 roughly corresponds to the normality (DIN SRT = −15.4 dB SNR). Note that DIN SRT ≤−13 dB SNR value  roughly corresponds to the cut-off inferred from the ROC curves (−12.9 dB SNR). Consequently, a subject with DIN SRT of −12.2  will be ranked in the hearing loss population. A Z-score of 2 also fits with the recommendation of the French ENT society , the normal SNR and the cut-off age was similar in both populations, which supports the reliably of the test to predict hearing loss. Three quarters of them were classified as normal (74%) and one quarter presented mild (9%) or more severe loss (17%), which is also consistent with English version (HearZA) realized in 2018 by De Sousa et al. . When weIn summary, the present results validate the efficiency of the Höra application in its purpose of screening and raising awareness on hearing loss. Since the application counsels a confirmation by a professional, listeners with hearing loss will benefit from a follow-up diagnostic assessment by a hearing specialist who will confirm the smartphone test result. The French Ministry of Health recently outlined the full reimbursement of hearing aids . In addiThe raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.Ethical review and approval was not required for the study on human participants in accordance with the local legislation and institutional requirements. The patients/participants provided their written informed consent to participate in this study.JCC, DS, CS, JLP, and FV designed and conceived the study. JCC and MJD coordinated the study. JCC and LG collected the data. JCC, DS, and CS performed the data and statistical analysis. JCC and JLP designed and realized the figures and wrote the first draft. All authors contributed to manuscript revision, read, and approved the submitted version.This work was supported by Fondation Pour l'Audition, non-profit foundation recognized as a public-interest since 2015.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Objective: To determine audiological and clinical results of cochlear implantation (CI) comparing two populations with single-sided deafness (SSD): post-lingually deaf children between 6 and 12 years of age, and post-lingually deaf adults, in order to evaluate the effect of CI in different age groups.Design: Retrospective case review.Setting: Tertiary clinic.Patients and Method: Twenty-three children and twenty-one adult patients that were candidates for CI with single-side deafness were included. In all cases we evaluate: Speech perception thresholds; disyllabic words test (65 dB SPL) were performed in the modalities S0–SCI–SNH and Auditory Lateralization Test. The Speech, Spatial, and Qualities of Hearing Scale (SSQ) questionnaire was also used. All results were obtained after 12 months of CI activation.Results: In children, the most common etiology was idiopathic sensory-neural hearing loss. They showed positive results in the Auditory Lateralization Test. In the Speech Test, word recognition in noise improved from 2% preoperatively to 61.1% at a mean follow-up of 1 year (S0 condition) in children [test with signal in CI side 60% and signal normal hearing side (plugged) 31%]. The processor was used for >12 h in all cases. With respect to the SSQ questionnaire, parents were more satisfied within the postoperative period than within the preoperative period. For adults, the most common etiology was idiopathic sudden sensorineural hearing loss (SNHL). Positive results in the Auditory Lateralization Test were found. With respect to the Speech Test in quiet conditions: Word recognition in noise improved from 5.7% preoperatively to 71.8% at a mean follow-up of 1 year [test with signal in CI side 68% and signal normal hearing side (plugged) 41%]. The processor was used for >12 h. In the SSQ questionnaire, the post-operative results showed a beneficial effect of the CI. No adverse events were reported during the study period. No differences were found between children and adults in all tests in this study.Conclusions: Cochlear implantation in post-lingually deaf adults and children with SSD can achieve a speech perception outcome comparable with CI in conventional candidates. Improvements in spatial hearing were also observed. Careful patient selection and counseling regarding potential benefits are important to optimize outcomes. Binaural hearing allows human beings to perform effective communication. Thus, single-sided deafness (SSD) leads to relevant hearing difficulties in most daily situations . Single-Cochlear implantation (CI) for single-sided deafness was firstly considered as a treatment to suppress severe tinnitus in adults, and, shortly after, binaural hearing re-establishment was considered as another benefit of this implantation on the single-sided hearing loss –5. CI asThe mechanisms by which single-sided deafness affects language, and academic and cognitive performance are related to impaired spatial capabilities and to binaural audition. Children with congenital SSD show a significant audiological and subjective improvement when they are treated with CI at an early age. In addition, children with post-lingual SSD and a short period of hearing deprivation are able to integrate their normal acoustic hearing with the electrical signal of the cochlear implant and they show binaural improvement , 12, 13.The aim of the present study is to determine audiological and clinical results of CI comparing two populations with SSD: post-lingually deaf children between 6 and 12 years of age, and adults, in order to evaluate the effect of CI in different age groups.This is an observational, descriptive, transversal study performed at Complejo Hospitalario Universitario Insular Materno Infantil de Gran Canaria, Hipoacusia Unit, Dept. Otolaryngology. conducted in adults, and children below 12 years of age, with acquired SSD, who received CI between October 2019 and May 2020 in our department, with a minimum follow-up of 12 months.In all cases, there were no implanted patients with ossification or any other cochlear anomalies that might prevent complete insertion of the electrode array; severe to profound hearing loss related to meningitis, multiple sclerosis, posterior fossa tumors, or central hearing related disorders; signs of retro-cochlear or central origin of hearing impairment; medical conditions that would contraindicate undergoing CI surgery ; psychological, neural, or mental disorders that would contraindicate undergoing CI surgery as verified by a psychologist; or any other additional handicaps that world prevent participation in evaluations.The cochlear implants used in this study were the Nucleus® Profile with Slim Electrode Modiolar CI632, and the Nucleus® CI612.The following presurgical tests were performed:Auditory Steady-State Responses (ASSR).Pure Tone Audiometry (PTA).Transient Evoked Otoacoustic Emissions (TEOAE).Cerebral Magnetic Resonance Imaging (MRI), and High-resolution computer tomography or Cone Beam CT.Genetic testing .Speech Test in quiet and noise settings.All subjects and their legal guardians in the case of children were informed about the benefits and disadvantages of the possible treatment options for single-sided deafness . The cochlear implantation expectations were also adjusted. Before the surgery, patients tested a bone-conduction device and the CROS system device.The post-surgical tests were performed after 12-months experience in the use of their respective speech processor. For the Speech Test, protocol for the assessment of hearing in the Spanish language and its version adapted to the infant population was used . The tesIn both groups, the TEOAE and ASSR responses were analyzed by the Eclipse Interacoustics Modules with the OtoAcces® Database.In the children group, cortical response was analyzed using the Hear System EARLab™ Aided Cortical Assessment (ACA) 1.0, using the stimuli “m,” “t,” and “s.”To perform the Lateralization Test on both groups, five speakers were used in positions 0°, 45°, 90°, 270°, and 370°, and 1,000 and 2,000 Hz pure tones were used at 65 dB. Signals were presented randomly 10 times per subject, and the test was considered positive when the success rate was ≥ 80%.All the tests were conducted in soundproof cabins (two connected soundproof cabins: one for each subject and the other for the operator), and by using an Audiotest 340 Interacoustics AS DK-5610 Assens. Denmark 2008 CE 0123 audiometer and Resolv Active Studio Monitor A5 45Hz- 27 Khz Biamped 50 watt speakers.A questionnaire measured the postoperative change in the parent's ratings of the child's performance in specific listening situations. Items were related to speech perception, spatial hearing, or other qualities of hearing . Regular reports about the device use, attitude, and performance were taken from adults and from parents , 17.t-test for paired samples. ANOVA or the non-parametric Kruskal–Wallis test for independent samples were used to compare average and median values in more than two groups. Statistical significance was set at P < 0.05.Data analysis was performed using SPSS 25.0 . Within The study obtained the approval of the Ethical Committee of our hospital in accordance with the Declaration of Helsinki. All adults and parents or legal guardians of the included participants provided written consent information.Forty-four cochlear implant users diagnosed with SSD were studied between June 2019 and February 2020. The children sample consisted of 29 subjects: 6 of which (20.69%) were non-implanted subjects because they presented congenital malformations: 3 had auditory nerve agenesis, 2 had cases of major cochlear malformation (common cavity), and 1 had a case of cochlear agenesis; and 23 of which (52.3%) had been implanted. The 23 patients in the implanted children group consisted of 10 boys (43.5%) and 13 girls (56.5%). With respect to the adult group, they were 21 patients (47.7%): 7 men (33.3%) and 14 women (66.7%).The average age of the children was 7.15 years with an SD of 1.46 years, while the adults' average age was 49.47 years (SD = 8.80). The average age of the whole sample was 27.35 years (SD = 22.23).With respect to the causes of SSD in children, their etiologies were progressive hearing loss of unknown origin in 17 subjects (73.91%), a sudden hearing loss in 4 subjects (17.39%), and cholesteatoma in 2 subjects (8.70%). With respect to the causes of SSD in adults, their etiologies were progressive hearing loss of unknown origin in 12 subjects (57.14%), sudden hearing loss in 4 subjects (19.05%), Meniere's disease in 3 subjects (14.29%), and acoustic trauma in 2 subjects (9.52%). The presurgical average PTA of the whole sample was 84 dB ±12 in the implanted ear and 28 dB ±4 in the normal-hearing ear.p = 0.04), being 12.13 months (SD = 4.52) in children and 9.85 months (SD = 2.41) in adults. While no significant differences were obtained when comparing the cochlear implantation periods (p > 0.05) of 17.61 months (SD = 5.76) in children and 15.14 months (SD = 3.26) in adults. With respect to the everyday use of the processor, the average use value was 10.16 h (range 7–13).In Discrimination in the Speech Test reached recognition values of 92 and 100%; it was observed that all the subjects reached 100% recognition if the summation effect was considered. The results obtained in the S0 modality (azimuth) were 48 and 68% (mean 56.55%) in discrimination, the SCI modality ranged from 52 to 68% (mean 61.36%), and, in the SNH modality, the recognition percentage ranged from 44 to 52% , in both groups, the adults' satisfaction within the post-surgical period ranged from 7 to 10, while the parents' satisfaction within the postoperative period reached 8 to 10, which were higher than those obtained for the preoperative period.t-test for equality of means. No statistically significant differences were obtained  method was then used in our patients. This method permits intensity level decreases and dynamic range increases, so it decreases the overlapping band while mapping and improves the audio quality of the signal representation .One of the most frequently used tools to measure the quality of life related to hearing is the Speech, Spatial, and Qualities of Hearing Scale (SSQ). In this study, significant benefits in the determinations of quality of life related to hearing were observed in both groups: by adults and children's parents.Several studies on adults with SSD have described better sound localization, speech comprehension in noisy environments, and decrease of tinnitus severity after cochlear implantation. In this study, a better sound localization was confirmed and, similarly to what was described by Hwa et al., an excellent speech comprehension after cochlear implantation was demonstrated , 26–28.One of the indirect signals to assess the real benefit of CI in children is the time of use of their speech processor. Motivated adults and children suffering from SSD but with good expectations can benefit from cochlear implantation, and it has been observed that most of them continue to be full-time cochlear implant users. Even when patients with bilateral deafness that have a cochlear implant show a decrease in the time of use of their speech processor, this decrease is generally due to a lack of objective hearing benefit and/or to social stigma. These aspects are important for the pediatric population of cochlear implant users , 30.In our study, children used their sound processor on a full-time basis and showed a good acceptation of the devices; these results are similar to those described by Ganek et al., who did not observe significant changes in the use of cochlear implants as the children grew up or acquired more hearing experience. Differently, Greaver et al. observed variability of the speech processor time of use in their study conducted on children , 32.A high incidence of auditory nerve agenesis within the population of children suffering from SSD was observed in this study, similar to that described in previous studies –35.Cochlear implantation in post-lingually deaf adults and children with SSD can achieve a speech perception outcome comparable with CI in conventional candidates. Improvements in spatial hearing were also observed. Careful patient selection and counseling regarding potential benefits are important to optimize outcomes, mainly in children with acquired SSD and those implanted after a longer period that may not have experienced a significant benefit , although other bilateral effects can be achieved.Taken together with other studies, this research enables doctors to take evidence-based clinical decisions about how to manage single-sided deafness in both children and adult groups. To obtain successful results, it must be considered that a rigorous selection of candidates and a proper adjustment between clinical advice and expectations are essential.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by Comité de Ética de la Investigación/Comité de Ética de la Investigación con Medicamentos Hospital Universitario de Gran Canaria Dr. Negrín (CEI/CEIm HUGCDN). Written informed consent to participate in this study was provided by the participants' legal guardian/next of kin.NF: data acquisition and manuscript writing. JF: data acquisition, verification and patients' fitting, and intraoperative testing. ÁRMa: original idea, manuscript writing, and surgeries. SB: manuscript and patients' agenda control. ÁRMi: manuscript and intraoperative testing. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Neomonachus schauinslandi) trained to participate in a psychophysical paradigm. We report absolute (unmasked) thresholds for narrowband signals measured in quiet conditions across the range of hearing and masked thresholds measured in the presence of octave-band noise at two frequencies. The behavioral audiogram indicates a functional hearing range from 0.1 to 33 kHz and poor sensitivity, with detection thresholds above 40 dB re 20 µPa. Critical ratio measurements are elevated compared to those of other seals. The apparently reduced terrestrial hearing ability of this individual—considered with available auditory data for a northern elephant seal (Mirounga angustirostris)—suggests that hearing in Monachinae seals differs from that of the highly sensitive Phocinae seals. Exploration of phylogenetic relationships and anatomical traits support this claim. This work advances understanding of the evolution of hearing in amphibious marine mammals and provides updated information that can be used for management and conservation of endangered Hawaiian monk seals.The auditory biology of Monachinae seals is poorly understood. Limited audiometric data and certain anatomical features suggest that these seals may have reduced sensitivity to airborne sounds compared to related species. Here, we describe the in-air hearing abilities of a Hawaiian monk seal (The online version contains supplementary material available at 10.1007/s00359-021-01498-y. Neomonachus schauinslandi, is a phocid  species endemic to the Northwestern and main Hawaiian Islands. There is significant conservation concern for this endangered marine mammal, with approximately 1400 individuals remaining in the wild —have been separated from their nearest living relatives for about 12 million years , spotted seals (Phoca largha), and ringed seals (Pusa hispida). Conversely, audiometric data are available for only two Monachinae species and both show relatively poorer hearing abilities. One northern elephant seal (Mirounga angustirostris) had an underwater hearing profile that was generally similar to that of the Phocinae seals but with somewhat elevated thresholds  with best sensitivity near 50 dB re 1 µPa. The frequency range of hearing is narrower in air (< 0.1 to > 30 kHz) with best sensitivity as low as − 13 dB re 20 µPa  vocalizations while on shore, which include mother–pup contact calls, threats, and other social vocalizations   Fig. .Fig. 1HaKE18 was trained using operant conditioning methods and fish reinforcement for voluntary participation in husbandry and research sessions. He received one-third to one-half of his daily diet of freshly thawed fish and squid during audiometric sessions; his diet was not constrained for experimental purposes. The monk seal typically participated in one audiometric session per day, 5 days per week. Data collection occurred over a 12-month period beginning in April 2019.Audiometric testing was conducted in a sound-attenuating, hemi-anechoic acoustic chamber  that was located 30 m from the seal’s living enclosure. This custom chamber had a 3.3 × 2.3 × 2.2 m testing room with double paneled stainless-steel walls and ceiling lined with fiberglass-filled aluminum wedges. The floor of the chamber was covered with thick (> 2 cm) foam mats. Sessions were controlled by a technician from an adjacent, sound-isolated room and monitored in real time with a video surveillance system.Leq) for frequencies from 0.04 to 20 kHz. Power spectral density levels for the entire study period were then calculated from the median of daily 1/3-octave band 50th percentile measurements (L50) that included each test frequency. Equipment limitations prevented absolute noise measurements above 20 kHz.Ambient noise in the acoustic chamber was measured prior to each session in the absence of the animal. One-minute, unweighted measurements were obtained with a battery-powered 2250 or 2270 sound analyzer  with a calibrated Brüel and Kjær 4189 free-field microphone (flat frequency response 0.006–20 kHz), which was placed at the location corresponding to the center of the monk seal’s head during testing. We calculated percentile statistics of 1/3-octave band noise levels from equivalent continuous sound pressure levels  corresponding to 50% correct detection  and 5% rise/fall times, generated using Hearing Test Program (HTP) software Finneran . The stiSignals were calibrated daily at the location of the external ear that had the higher received level during spatial mapping. Signals were measured at a range of amplitudes and evaluated in the time and frequency domains to ensure integrity. During spatial mapping and calibration, signals were received by a MK301 microphone capsule  with a C617 body  and BPS-1 power supply  and passed through the same filter and data acquisition hardware used for signal generation before being measured in HTP. Sound field mapping and daily calibration were conducted in the absence of the animal.We measured masked hearing thresholds at the two frequencies with lowest absolute thresholds (800 Hz and 3200 Hz) in the presence of octave-band white noise centered at each test frequency. Critical ratios (CRs) were calculated as the difference between the SPL of the masked threshold and the power spectral density level of the masking noise Fletcher . Due to 1The auditory masking paradigm was similar to that used for the audiogram, with the addition of masking noise paired with the onset of the trial light. Masking noise was generated and spectrally flattened with custom LabVIEW software , projected through the computer sound card, and mixed with the test signal at a P1000 power amplifier  before reaching the JBL 2123H speaker. Masker duration was 8 s  with the received spectral density level 10 dB above the corresponding absolute hearing threshold. Masked thresholds were measured using the same adaptive staircase procedure described earlier.We spatially mapped the masking noise to ensure a stable sound field using the 14-position grid described previously. The 1/3-octave band levels comprising the octave-band masker were measured to confirm acceptable variability (≤ 6 dB) of all three bands across the mapping grid. Additionally, mapping confirmed that the center 1/3-octave band level measured at all 14 positions fell within 3 dB of that received at the daily calibration position. The masker was calibrated prior to each session to confirm that the center 1/3-octave band was within 1 dB of expected and that the surrounding 1/3-octave bands were within 3 dB of expected. During spatial mapping and calibration, masking noise was received through the Microtech microphone and analyzed with Spectra-PLUS software v.5.2.0.14  on a laptop computer.To evaluate external ear anatomy in relation to what is known about hearing capabilities in the two Phocidae subfamilies, we conducted a simple comparison of the sizes of the external ear openings for the 18 extant true seal species. We used Adobe Illustrator v.23.1.1  to digitally trace a silhouette of each species from reference photos, including the meatal opening and other anatomical landmarks. Seals were hauled out or at the surface of the water in all photos.Absolute (unmasked) in-air hearing thresholds, false alarm rates, ambient noise levels, and threshold-to-noise offsets are provided for one Hawaiian monk seal in Table The audiogram lacked the characteristic U-shape of mammalian hearing curves and instead was relatively flat with a distinct elevation at 6.4 kHz. The functional range of hearing—the range of frequencies audible at 60 dB re 20 μPa .Masked thresholds, masking noise levels, critical ratios, and false alarm rates evaluated at two frequencies are provided in Table Digitally illustrated silhouettes of all 18 extant true seals are provided in Fig. This Hawaiian monk seal exhibited notably poor terrestrial hearing, with best sensitivity of 40 dB re 20 µPa and a range of functional hearing extending from 0.1 to 33 kHz. Hearing range was constrained in both the low- and high-frequency regions of the audiogram relative to that of Phocinae seals evaluated under the same conditions; best sensitivity was approximately 50 dB higher. The distinct upward notch at 6.4 kHz, which is also evident in the underwater audiogram of this individual  were discovered in New Zealand and identified as a new species of monk seal—the first monk seal ever found in the southern hemisphere  hearing group proposed in recent marine mammal noise exposure criteria Supplementary file2 (PDF 277 KB)Below is the link to the electronic supplementary material.


Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder characterised by muscle weakness and impaired sensory function. The present study provides a comprehensive literature review of the burden of illness of CIDP.Systematic literature search of PubMed, Embase, and key conferences in May 2019. Search terms identified studies on the epidemiology, humanistic burden, current treatment, and economic burden of CIDP published since 2009 in English.n = 9), humanistic burden (n = 7), current treatment (n = 40), and economic burden (n = 8) of CIDP. Epidemiological studies showed incidence and prevalence of 0.2–1.6 and 0.8–8.9 per 100,000, respectively, depending on geography and diagnostic criteria. Humanistic burden studies revealed that patients experienced physical and psychosocial burden, including impaired physical function, pain and depression. Publications on current treatments reported on six main types of therapy: intravenous immunoglobulins, subcutaneous immunoglobulins, corticosteroids, plasma exchange, immunosuppressants, and immunomodulators. Treatments may be burdensome, due to adverse events and reduced independence caused by treatment administration setting. In Germany, UK, France, and the US, CIDP economic burden was driven by direct costs of treatment and hospitalisation. CIDP was associated with indirect costs driven by impaired productivity.Forty-five full texts and nineteen conference proceedings were identified on the epidemiology  contains supplementary material, which is available to authorized users. Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare, immune-mediated disorder in which an aberrant immune response causes demyelination and axonal damage of the peripheral nerves , 2. The CIDP is a long-term condition with a variable course that can be relapsing–remitting, stepwise progressive, or gradually progressive , 3. AxonEuropean Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) guidelines provide recommendations on CIDP treatments, with the goal of reducing symptoms and, if possible, maintaining long-term remission , 12. TreTreatment of CIDP is complicated by challenges in diagnosis . The disThere are significant challenges in characterising the burden of illness for rare diseases such as CIDP, and evidence can be limited . IdentifKeywords related to the study topics were used to search relevant research articles in the MEDLINE (including In-process) and Embase databases. Only articles including human data and published in English from May, 2009 to May, 2019 were included. Separate search terms were used for each review category. The search algorithms, limits, and number of hits obtained are summarised in Online Resource 1.To ensure inclusion of more recent studies that had not yet been published in peer-reviewed journals, we reviewed non-peer-reviewed articles from the following neuromuscular conferences and conferences relevant to health economic and outcomes research, published between 2017 and 2019: International Society for Pharmacoeconomics and Outcomes Research (ISPOR) conference, International Congress on Neuromuscular Diseases (ICNMD), and Annual Meetings of the Peripheral Nerve Society (PNS). It was assumed that any conference outputs prior to these dates would have been published in a peer-reviewed journal at the time that the searches were conducted.Beta. Eligible studies were identified by one reviewer for inclusion in the study according to the predefined inclusion and exclusion criteria , humanistic burden (n = 7), current treatments (n = 42), and economic burden (n = 8). Figure A total of 2343 studies were identified from the MEDLINE and Embase databases. After abstract screening, 130 full texts were assessed, of which 45 articles met the inclusion criteria and were taken forward to data extraction. After inclusion of 21 abstracts identified from the ICNMD, PNS, and ISPOR conferences, 66 articles were deemed to have met the inclusion criteria and were included in the analysis. Included articles were categorised by topic: epidemiology —typically derived from patient clinical databases—or based on literature reviews  , 5725, 5CIDP was also associated with indirect costs, driven predominantly by impaired productivity , 25. In p < 0.0001) associated with hospital admission and patient care costs [Total costs and resource use varied depending on the setting of IVIG administration and other factors, such as patient well-being and physical functioning , 55. Le re costs . In Franre costs .p < 0.005 for both [p < 0.011) but not direct costs [In Germany, increased direct and medication costs were significantly associated with functional disability (measured by INCAT) and clinically relevant depressive symptoms (measured by BDI-II), for both . The prefor both . Improvect costs .The current review provides the first systematic assessment of the burden of illness of CIDP. The findings establish that CIDP is a rare disease, associated with impaired HRQoL, particularly relating to physical well-being, and an economic burden. Patients with CIDP may also experience burden due to treatment. Long-term steroid use is associated with a high risk of AEs, and parenteral therapies, such as IVIG, SGIG and plasma exchange, are associated with burden of administration and potential impact on patient independence , 16.n = 19–360) and diagnostic criteria. Low sample sizes are common when identifying and recruiting patients with rare diseases [Epidemiology studies confirmed that CIDP is a rare disease  , 6, 20. diseases . In contdiseases . Moreovediseases . Misdiagdiseases , 18, 37.diseases , 12, 37.CIDP was associated with impaired patient well-being, due to the physical impact of CIDP and, in some cases, the presence of mental health conditions. Patients with CIDP had EQ-5D index scores of 0.68 in Germany and 0.62 in the UK, substantially below normative values for these countries  , 61. ForTreatment setting, mental health, and physical functioning were associated with an increased economic burden in CIDP; however, only eight studies on economic burden were identified and results need to be interpreted with caution. While treatment costs were the primary cost drivers, research in USA and France indicates that the cost of treatment of CIDP reduces if patients can receive IVIG treatment at home rather than in a hospital setting . DepressThe physical and psychological impact of CIDP is implicated in productivity losses and indirect costs. Early retirement was reported among patients with CIDP , 26. TheCurrent therapies can improve patient well-being, but are also associated with tolerability issues and challenges around route of administration . IVIG anSCIG has been developed as an alternative to IVIG, providing flexible self-administration at home . While IEFNS/PNS guidelines (2010) do not provide guidance on long-term management of CIDP, nor on SCIG, as evidence on these topics was insufficient at the time of guideline development . TreatmeThere may be additional publications not identified in this review that are important for characterising the burden of disease in CIDP. For example, relevant data may have been published that were excluded as a result of the limits to the study type and publication dates. Searches were restricted to English language publications, which may have excluded relevant studies published in other languages.No studies were identified related to treatment guidelines in the current review; however, the EFNS/PNS guidelines on management of chronic inflammatory demyelinating polyradiculoneuropathy” were published within the dates in scope . This puLimitations characteristic of CIDP were identified, such as low number of relevant publications and low sample sizes in studies. The limited number of publications available on epidemiology, humanistic burden, and economic burden impairs the current assessment of the burden of disease. The low number of publications identified reflects the rarity of the disease, as research into rare disease may face greater challenges in recruiting patients and obtaining funding, because more common diseases have a greater economic impact . The majThis review provides the first systematic assessment of the burden of illness across all aspects of CIDP. The findings establish that CIDP is among the rarest neuropathies and is associated with substantial patient burden. Further research is required to fully characterise the burden of CIDP, particularly the physical impact on patients, and to understand how appropriate treatment can support mitigating disease burden for patients and healthcare systems.Supplementary material 1 (PDF 111 kb)Supplementary material 2 (PDF 150 kb)Supplementary material 3 (PDF 471 kb)Supplementary material 4 (PDF 226 kb)Below is the link to the electronic supplementary material.