Driver drowsiness is a leading contributing factor to vehicle crashes, although loss of sleep impacts individuals to different degrees. While in-vehicle technologies can monitor a driver for signs of tiredness and distraction while on the road, there is obvious benefit in predicting impairment before a driver even enters the vehicle. Here we sought to examine whether driver impairment can be predicted using subjective reports of drowsiness and using ocular-motor behaviour recording using the BrainEye mobile phone app. Eighteen participants took part in a 20-min baseline drive in a driving simulator along a highway, followed by a restricted sleep for four hours between 10 p.m. and 2 a.m. Participants returned to the driving simulator after 9 a.m. to complete a second drive while sleep deprived. An increase in subjective reports of drowsiness predicted reduced average and maximum driving speed, while an BrainEye derived ocular-motor model predicted deviations in lateral position (swerving) and speed variability. Reducing a vehicle's speed to counteract the impact of drowsiness has been previously shown as a compensatory driving mechanism. Our findings reveal that ocular-motor parameters may predict impairment in driving that is associated with reduced cognitive capacity (meaning driving requires increased cognitive effort) and decreased attentional vigilance. While these results are preliminary, being able to use a mobile phone app to predict driver impairment may assist individuals to decide whether they are competent to get behind the wheel.

Objective:Exercise-assistance strategies are useful in allowing mobility-impaired patients to access the benefits of exercise. This trial is the first of the Reviver device, which facilitates exercise via a novel strength and balance training mechanism. The objective was to examine the effect of a 12-week Reviver intervention on symptoms of Parkinsonism, and to pilot the randomised controlled trial design, including randomisation and acceptance of the exercise intervention. Methods:This was a pilot, parallel-arm randomised controlled trial with assessor blinding. Participants (n=30: 22 with Parkinson's disease (PD) and 8 with atypical Parkinsonism conditions (AP)) were allocated to either experimental or control group. The experimental group received 24 sessions of 30 min on the Reviver over 12 weeks, the control group received their standard care. The Movement Disorders Society Unified Parkinson's Disease Rating Scale, and secondary outcomes (balance, gait, mobility, lower-body strength/coordination, tremor and grip strength) were acquired at endpoints the week prior to intervention commencement and the week after intervention termination. Recruitment progress, adherence to intervention, acceptability of intervention and adverse effects were also recorded. Results:For the PD cohort, lower-body strength/coordination (5× Sit-To-Stand; b(95% CI)=-3.02 (-5.16 to -0.89), p=0.013), gait (self-selected walking speed; b=12.48 (2.18 to 22.78), p=0.029, stride length; b=9.75 (0.99 to 18.52), p=0.043) and backward walking speed (b=14.25 (1.93 to 26.57), p=0.038) were improved by the intervention. No significant effect of intervention on the outcome variables was found in the AP cohort. No serious adverse events were recorded. Median adherence to treatment was 95.8%. Interpretation:This pilot trial indicates that the Reviver is a safe and well-tolerated exercise-assistance intervention. The Reviver showed some indications of benefit in our secondary measures for PD participants, but not in our primary outcome. This was a small sample, short duration pilot study, and further studies with larger samples and higher exercise volume are warranted to fully assess the safety and efficacy of the device.

Concussion is a common consequence of engaging in collision sports, with the often mild, transient nature of symptoms posing a considerable diagnostic and management challenge. This challenge is vastly magnified for athletes competing at grassroots/non-professional levels, who lack field side access to medical expertise in the assessment of a player’s capacity to continue playing or need for further medical attention. The aim of this pilot study was to evaluate the utility of the BrainEye application and hardware (BrainEye platform) as a concussion screening tool, specifically determining (1) its sensitivity and specificity with respect to identifying an individual with a clinically diagnosed concussion, (2) the stability of the platform through test completion/failure rates, and (3) its usability through operator feedback and uptake/integration into concussion management protocols. Using the BrainEye platform, 348 male professional Australian Rules footballers from 10 Australian Football League (AFL) clubs completed 4 simple ocular protocols (pupillary light reflex, PLR; smooth pursuit eye movements, SMP; near-point convergence, NPC; horizontal gaze nystagmus, HGN) at baseline, prior to the onset of the 2022 AFL season, and following the clinical diagnosis of concussion throughout the season during a game/training/practice (n = 11 players immediately following a concussive event, and on 14 occasions 2–7 days following a concussive event). Although club participation and protocol adherence rates were suboptimal, with clubs citing COVID-19 restrictions and cumbersome hardware set-up as primary reasons for non-participation/missing data, a BrainEye score that derived from an algorithm combining smooth pursuit and pupillary light reflex measures, achieved 100

Idiopathic intracranial hypertension (IIH) is increasingly prevalent, yet longitudinal outcome data are scarce. This study aimed to characterise demographic and longitudinal clinical changes in a cohort of patients with IIH. Retrospective cohort analysis on adult patients diagnosed with IIH (Friedman criteria) enrolled in the neuro-ophthalmology database (NODE) across two tertiary centres. Baseline demographic data was obtained at first assessment, with clinical and paraclinical outcomes collected longitudinally. Multivariable statistical analysis identified factors associated with poorer visual outcomes. A total of 221 patients were included. 91.8

Visual snow syndrome (VSS) is a neurological disorder that is predominantly characterized by persistent, dynamic visual disturbances, experienced across the entire visual field. Earlier research highlighted the significance of distinct brain regions, exhibiting alterations in both anatomical structure and functional characteristics. To further investigate the functional role of these regions, we examined the resting-state connectivity between these areas in individuals with VSS and the relation with VSS symptoms and oculomotor measures of visual processing. Forty patients with VSS (53% females; age = 33.2 ± 10.1 years; 22 with migraine) and 60 healthy controls (58% females; age = 32.0 ± 9.2 years) were scanned using 7 Tesla MRI system. High spatial and temporal resting-state (RS) functional (TR = 800 ms, 1.6 mm isotropic) and anatomical (MP2RAGE, 0.75 mm isotropic) images were acquired. Resting-state data were pre-processed (motion correction, temporal filtering and spatial smoothing), functional connectivity was calculated between regions of interest and compared between groups. Significant metrics were compared with VSS patients with and without migraine and correlated with oculomotor measures (prosaccade and anti-saccade latencies), number of VSS symptoms, self-rated VSS intensity and perceived disruptiveness. Compared to healthy controls, VSS patients demonstrated significantly higher connectivity between the supramarginal gyrus and lateral occipital cortex (P = 0.016) and fusiform (P = 0.007), lower connectivity between the supramarginal gyrus and pallidum (P = 0.032), as well as between the parahippocampal gyrus and lateral occipital cortex (P = 0.007), which related to higher perceived disruptiveness (P = 0.002, r = -0.489). No differences were found between VSS with and without migraine. This study revealed altered functional connectivity strength in individuals with VSS, suggesting stronger connectivity between cortical areas, particularly centred around the supramarginal gyrus, and disconnections with deep grey matter and temporal cortices, which associated with perceived disruptiveness of VSS.

IntroductionMyasthenia gravis (MG) is an autoimmune disease that causes extraocular muscle weakness in up to 70–85% of patients, which can impact quality of life. Current diagnostic measures are not very sensitive for ocular MG. This study aimed to compare fixation instability (inability to maintain gaze on a target) in patients with MG with control participants using video-oculography.MethodsA prospective study of 20 age-and sex-matched MG and control participants was performed using a novel protocol with the EyeLink 1000 plus ©. Bivariate contour ellipse area (BCEA) analysis, number of fixations on a target, and percentage of dwell time of fixations in the target interest area (IA) were calculated. Inter-eye (right vs. left) comparisons were performed using paired t-tests, and inter-group (MG vs. control) comparisons were performed using independent samples t-tests.ResultsThere were no inter-eye differences in the BCEAs between control eyes and MG eyes. However, the BCEAs were larger in both the right (RE) and left (LE) eyes of MG patients in the right (RE p = 0.029, LE p = 0.033), left (RE p = 0.006, LE p = 0.004), upward (RE p = 0.009, LE p = 0.018), and downward (RE p = 0.006, LE p = 0.006) gaze holds of the controls. The total mean sum of gaze hold fixations in all directions was greater in MG patients than in control participants (354 ± 139 vs. 249 ± 135, p = 0.020), with horizontal gaze holds showing greater differences than vertical gaze holds (p = 0.007 vs. p = 0.097). The percentage of dwell time in the target IA was lower in MG patients, but this only reached significance in the right gaze hold (p = 0.003).ConclusionMG patients showed greater BCEA values and refixations and lower target IA percentages of dwell time during gaze hold than control participants, suggesting extraocular neuromuscular junction instability and fatigue. Interestingly, there were no significant inter-eye differences in MG participants. This study is limited by the small number of patients but adds to the current literature exploring video-oculography in MG patients as a novel diagnostic tool. Further studies are recommended for translation into clinical practice.

Saccadic eye movements are rapid, precisely coordinated shifts that centre the fovea on a visual target. Their control relies on the integration of cognitive processes spanning multiple brain regions. High-resolution video-oculography enables precise measurement of saccadic dynamics, offering a window into disruptions affecting these networks. This review examines the neuroanatomy and physiology of saccadic eye movements, emphasising the cognitive mechanisms underlying their control and the methodologies used for their assessment. We synthesise evidence from saccadic eye movement testing across a spectrum of neurological diseases, highlighting its potential as an early and sensitive biomarker for detecting subclinical disease impact. While current findings underscore its promise as a non-invasive, objective tool for tracking neuropsychological dysfunction in these various diseases, we also address existing limitations and critical directions for future research towards improving clinical utility.

Background Eating disorders have one of the highest mortality of all mental illnesses but are associated with low rates of screening and early intervention. In addition, there remains considerable uncertainty regarding the use of current standardised screening tools in measuring eating pathology in vegetarians and vegans. With these groups presenting as potential at-risk groups for disordered eating development, the present study aimed to develop and preliminary validate a novel eating disorder screening tool, the Vegetarian Vegan Eating Disorder Screener (V-EDS). Methods We utilised a mixed-methods approach, comprising four phases. Results A conceptual framework was developed from 25 community, clinician, and lived experience interviews and used to derive a preliminary set of 163 items (Phase 1). Phase 2 piloted the items to establish face and content validity through cognitive debriefing interviews of 18 additional community, clinician, and lived experience participants, resulting in a reduced, revised questionnaire of 53 items. Phase 3 involved scale purification using Item Response Theory in analysis of 230 vegetarians and 230 vegans resulting in a further reduced 18-item questionnaire. Phase 4 validated the screening tool in a large community sample of 245 vegetarians and 405 vegans using traditional psychometric analysis, finding the V-EDS supports a unidimensional factor structure with excellent internal consistency (α = 0.95–0.96) and convergent validity (0.87–0.88), and moderate discriminate validity (0.45–0.55). Conclusions This study provided strong initial support for the psychometric validity and theoretical assumptions of the novel V-EDS screening tool. The V-EDS has the potential to increase early intervention rates for vegetarians and vegans experiencing eating disorder symptoms, further supporting advocacy and treatment approaches for these expanding dietary groups.

Background and Objectives:Myasthenia gravis (MG) is a condition with significant phenotypic variability, posing a diagnostic challenge to many clinicians worldwide. Prolonged diagnosis can lead to reduced remission rates and morbidity. This study aimed to identify factors leading to a longer time to diagnosis in MG that could be addressed in future to optimize diagnosis time.Methods:One hundred and ten patients from 3 institutions in Melbourne, Australia, were included in this retrospective cohort study. Demographic and clinical data were collected for these patients over the first 5 years from diagnosis and at 10 years. Nonparametric statistical analysis was used to identify factors contributing to a longer diagnosis time.Results:The median time for MG diagnosis was 102 (345) days. 90% of patients were diagnosed before 1 year. Female patients took longer than male patients to be diagnosed (p = 0.013). The time taken for first presentation after symptom onset contributed most to diagnosis time (median 17 [141] days), with female patients and not working as contributory factors. Neurology referral took longer if patients had diplopia (p = 0.022), respiratory (p = 0.026) symptoms, or saw an ophthalmologist first (p < 0.001). Outpatient management compared with inpatient was associated with a longer time to be seen by a neurologist from referral (p < 0.001), for the first diagnostic result to return (p = 0.001), and for the result to be reviewed (p < 0.001). Ocular MG had a median greater time to neurologist review than generalized MG (median 5 [25] days vs 1 [13] days, p = 0.035). Electrophysiology tests took longer for outpatients than inpatients (median 21 [35] days vs 2 [8] days, p < 0.001). Outpatients were also started on treatment later than inpatients (p < 0.001). There was no association of MG severity, ethnicity, age, medical and ocular comorbidities, and public or private health service on diagnosis time. There was also no impact of time to diagnosis on Myasthenia Gravis Foundation of America outcomes, number of follow-ups or hospitalizations, or prevalence of treatments used. This study is limited by low patient numbers and its retrospective nature.Discussion:This study identified several factors that can contribute to a prolonged diagnosis time of MG. Patient and clinician education about MG and outpatient diagnostic efficiency needs emphasis. Further studies are also needed to explore the delayed presentation time of women and nonworking patients in MG.

Purpose:Visual snow is the hallmark of the neurological condition visual snow syndrome (VSS) but the characteristics of the visual snow percept remain poorly defined. This study aimed to quantify its appearance, interobserver variability, and effect on measured visual performance and self-reported visual quality. Methods:Twenty-three participants with VSS estimated their visual snow dot size, separation, luminance, and flicker rate by matching to a simulation. To assess whether visual snow masks vision, we compared pattern discrimination thresholds for textures that were similar in spatial scale to visual snow as well as more coarse than visual snow, in participants with VSS, and with and without external noise simulating visual snow in 23 controls. Results:Mean and 95% confidence intervals for visual snow appearance were: size (6.0, 5.8-6.3 arcseconds), separation (2.0, 1.7-2.3 arcmin), luminance (72.4, 58.1-86.8 cd/m2), and flicker rate (25.8, 18.9-32.8 frames per image at 120 hertz [Hz]). Participants with finer dot spacing estimates also reported greater visibility of their visual snow (τb = -0.41, 95% confidence interval [CI] = -0.62 to -0.13, P = 0.01). In controls, adding simulated fine-scale visual snow to textures increased thresholds for fine but not coarse textures (F(1, 22) = 4.98, P = 0.036, ηp2 = 0.19). In VSS, thresholds for fine and coarse textures were similar (t(22) = 0.54, P = 0.60), suggesting that inherent visual snow does not act like external noise in controls. Conclusions:Our quantitative estimates of visual snow constrain its likely neural origins, may aid differential diagnosis, and inform future investigations of how it affects vision. Methods to quantify visual snow are needed for evaluation of potential treatments.

Background: Cognitive impairment can emerge in the earliest stages of multiple sclerosis (MS), with heterogeneity in cognitive deficits often hindering symptom identification and management. Sensory–motor dysfunction, such as visual processing impairment, is also common in early disease and can impact neuropsychological task performance in MS. However, cognitive phenotype research in MS does not currently consider the relationship between early cognitive changes and visual processing impairment. Objectives: This study explored the relationship between cognition and visual processing in early MS by adopting a three-system model of afferent sensory, central cognitive and efferent ocular motor visual processing to identify distinct visuo-cognitive phenotypes. Methods: Patients with clinically isolated syndrome and relapsing–remitting MS underwent neuro-ophthalmic, ocular motor and neuropsychological evaluation to assess each visual processing system. The factor structure of ocular motor variables was examined using exploratory factor analysis, and phenotypes were identified using latent profile analysis. Results: Analyses revealed three ocular-motor constructs (cognitive control, cognitive processing speed and basic visual processing) and four visuo-cognitive phenotypes (early visual changes, efferent-cognitive, cognitive control and afferent-processing speed). While the efferent-cognitive phenotype was present in significantly older patients than was the early visual changes phenotype, there were no other demographic differences between phenotypes. The efferent-cognitive and cognitive control phenotypes had poorer performance on the Symbol Digit Modalities Test compared to that of other phenotypes; however, no other differences in performance were detected. Conclusion: Our findings suggest that distinct visual processing deficits in early MS may differentially impact cognition, which is not captured using standard neuropsychological evaluation. Further research may facilitate improved symptom identification and intervention in early disease.

Purpose:Palinopsia (persistent afterimages and/or trailing) is a common but poorly understood symptom of the neurological condition visual snow syndrome. This study aimed to collect a phenotypical description of palinopsia in visual snow syndrome and probe for abnormalities in temporal visual processing, hypothesizing that palinopsia could arise from increased visibility of normal afterimage signals or prolonged visible persistence. Methods:Thirty controls and 31 participants with visual snow syndrome (18 with migraine) took part. Participants completed a palinopsia symptom questionnaire. Contrast detection thresholds were measured before and after brief exposure to a spatial grating because deficient contrast adaptation could increase afterimage visibility. Temporal integration and segregation were assessed using missing-element and odd-element tasks, respectively, because prolonged persistence would promote integration at wide temporal offsets. To distinguish the effects of visual snow syndrome from comorbid migraine, 25 people with migraine alone participated in an additional experiment. Results:Palinopsia was common in visual snow syndrome, typically presenting as unformed images that were frequently noticed. Contrary to our hypotheses, we found neither reduced contrast adaptation (F(3.22, 190.21) = 0.71, P = 0.56) nor significantly prolonged temporal integration thresholds (F(1, 59) = 2.35, P = 0.13) in visual snow syndrome. Instead, participants with visual snow syndrome could segregate stimuli in closer succession than controls (F(1, 59) = 4.62, P = 0.04, ηp2 = 0.073) regardless of co-occurring migraine (F(2, 53) = 1.22, P = 0.30). In contrast, individuals with migraine alone exhibited impaired integration (F(2, 53) = 4.44, P = 0.017, ηp2 = 0.14). Conclusions:Although neither deficient contrast adaptation nor prolonged visible persistence explains palinopsia, temporal resolution of spatial cues is enhanced and potentially more flexible in visual snow syndrome.

Background The vegetarian vegan eating disorder screener (V-EDS) is an 18-item self-report screening tool designed to assess the unique elements of eating disorder symptomology in vegetarians and vegans. Previous results have suggested strong initial psychometric properties in non-clinical community samples of vegetarians and vegans. The present study sought to identify a preliminary threshold cut-off score to discriminate eating disorder pathology in a self-reported clinical and community sample. Methods This study involved secondary analysis using data collected in McLean et al. (Development and preliminary validation of a novel eating disorder screening tool for vegetarians and vegans: the V-EDS, 2023), comprising 599 non-clinical participants and 51 self-reported clinical participants. Receiver operating characteristic (ROC) curve analysis was used to compute possible cut-off values for the V-EDS. Results: ROC analysis indicated good performance of the V-EDS (area under the curve = 0.87), with integration of the Youden index demonstrating a global score of ≥ 18 to be optimal in predicting clinical caseness with good sensitivity (0.804) and specificity (0.843). Conclusions The present study fills an important gap as the first to investigate an optimal V-EDS score to discriminate level of impairment from eating disorder pathology in a sample of vegetarian and vegan community and self-reported clinical participants. We extend the utility of the V-EDS in discovering good discrimination power in classifying clinical caseness with a cut-off score of 18 shown to optimise the trade-off between sensitivity and specificity. Future research should focus on expanding the psychometric properties of the V-EDS in larger and more diverse participant groups, including gender, age, cultural identity, and eating disorder history.

To identify key symptoms reported by patients and observed by clinicians due to the wearing-off effect (WOE) associated with multiple sclerosis (MS) disease-modifying therapies (DMTs), and to better understand patient and physician perspectives on the WOE.

Background Idiopathic intracranial hypertension (IIH) is rising in prevalence, with significant morbidity typically affecting overweight women of reproductive age. There is a paucity of data regarding longitudinal clinical outcomes in Australia. Objectives To describe longitudinal clinical and paraclinical changes in a tertiary cohort of IIH patients. Methods A retrospective analysis was performed on adult patients diagnosed with definite IIH (Friedman criteria), prospectively enrolled in the neuro-ophthalmology database (NODE) at a single tertiary centre in Victoria. Demographic data obtained at baseline with sequential visits including clinical evaluation, automated perimetry and optical coherence tomography. Multivariate statistical analysis was performed in R. Results 116 patients were included; 93.1% were female. Mean(+/- standard deviation) time from first consultation to diagnosis was 6.72(43.16) days, with average follow-up duration of 352.7 days (range 0–1232) over 4.73 visits. Mean age at diagnosis was 28.8(6.8) years with mean body mass index (kg/m2) of 39.1(9.7). Papilloedema was found in 96.5%, mean Frisen grade of 1.96(0.98). Mean CSF opening pressure was 31.29(4.90) cmH20. No visual acuity change was observed over time (mean LogMAR 0.02 right eye, 0.05 left eye). Time was associated with reduced retinal nerve fibre layer thickness (p=0.02) and papilloedema grade (p<0.001). BMI at diagnosis strongly correlated with mean perimetric mean deviation (PMD) where each one-unit increase in BMI produced a 0.10 decrease in PMD (p=0.01). Conclusions Our demographic and clinical phenotype data are comparable with international cohorts. The main predictor of worse visual outcome was baseline BMI, providing a strong rationale for focused weight loss interventions.

Identifying when recovery from a sports-related concussion (SRC) has occurred remains a challenge in clinical practice. This study investigated the utility of ocular motor (OM) assessment to monitor recovery post-SRC between sexes and compared to common clinical measures. From 139 preseason baseline assessments (i.e. before they sustained an SRC), 18 (12 males, 6 females) consequent SRCs were sustained and the longitudinal follow-ups were collected at 2, 6, and 13 days post-SRC. Participants completed visually guided, antisaccade (AS), and memory-guided saccade tasks requiring a saccade toward, away from, and to a remembered target, respectively. Changes in latency (processing speed), visual-spatial accuracy, and errors were measured. Clinical measures included The Sports Concussion Assessment Tool, King-Devick test, Stroop task, and Digit span. AS latency was significantly longer at 2 days and returned to baseline by 13-days post-SRC in females only (P < 0.001). Symptom numbers recovered from 2 to 6 days and 13 days (P < 0.05). Persistently poorer AS visual-spatial accuracy was identified at 2, 6 and 13 days post-SRC (P < 0.05) in both males and females but with differing trajectories. Clinical measures demonstrated consistent improvement reminiscent of practice effects. OM saccade assessment may have improved utility in tracking recovery compared to conventional measures and between sexes.

Objective:To explore how various stakeholders (patients living with multiple sclerosis [PlwMS], caregivers [CGs], health care practitioners [HCPs], advocacy groups) describe symptoms, timing, coping strategies, and impact on quality of life (QoL) of the wearing-off effect (WOE) while receiving disease-modifying therapies (DMTs; natalizumab, ocrelizumab, ofatumumab, rituximab).Background:Symptoms such as fatigue, mobility issues, and physical pain toward the end of treatment cycles (WOE) have been reported in PlwMS receiving DMTs. Patients on social media report a QoL impact associated with WOE.Design/Methods:Publicly available posts related to WOE on social media, blogs, and forums were reviewed. WOE-specific posts authored in English by key stakeholders and posted between February 1, 2020 and February 16, 2022 were analyzed. Posts were identified through a specific search term–based funneling methodology.Results:We identified 43,834 posts related to broader MS and WOE; 730 conversations were WOE specific, with 725 authored by PlwMS or CGs. Of these 725 posts, 535 were related to experiencing WOE and 277/535 posts mentioned WOE-associated symptoms. The most commonly reported WOE durations were 2–4 weeks; fatigue was the most mentioned symptom, followed by mobility issues and physical pain. Treatment was specified in 374/535 posts; 9% of these mentioned a QoL impact, such as need for more downtime, interference with work, and difficulty walking. WOE coping strategies mentioned by patients included switching to other DMTs, reducing intervals between cycles, and taking steroids/other medications. WOE-related conversations by HCPs and advocacy groups were scarce (4 and 1 posts, respectively).Conclusions:Mentions of WOE by patients receiving DMTs and reports of WOE-related symptoms impacting QoL were common. Factors like differing DMT durations and numbers of patients receiving different DMTs make observations of social media conversations prone to an inherent bias. Further research regarding WOE and potential gaps between HCP and patient perceptions/awareness of WOE is needed. Disclosure: Mr. Clement has received personal compensation for serving as an employee of Novartis. Mr. Clement has stock in Roche. Joanne Fielding, 24833 has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Novartis . The institution of Joanne Fielding, 24833 has received research support from BioEye. The institution of Joanne Fielding, 24833 has received research support from Equity Trustees. The institution of Joanne Fielding, 24833 has received research support from Macquarie Group Foundation. The institution of Joanne Fielding, 24833 has received research support from Genzyme. The institution of Joanne Fielding, 24833 has received research support from Biogen. The institution of Joanne Fielding, 24833 has received research support from Open Medicines Australia. The institution of Joanne Fielding, 24833 has received research support from EyeOnVision. Ms. Serceau has nothing to disclose. Ms. Robinson has nothing to disclose. Chinmay Deshpande has received personal compensation for serving as an employee of Novartis Pharmaceutical Corporation . Chinmay Deshpande has stock in Novartis Pharmaceutical Corporation .

People with multiple sclerosis (pwMS) frequently present with deficits in binaural processing used for sound localization. This study examined spatial release from speech-on-speech masking in pwMS, which involves binaural processing and additional higher level mechanisms underlying streaming, such as spatial attention. 26 pwMS with mild severity (Expanded Disability Status Scale score <3) and 20 age-matched controls listened via headphones to pre-recorded sentences from a standard list presented simultaneously with eight-talker babble. Virtual acoustic techniques were used to simulate sentences originating from 0°, 20°, or 50° on the interaural horizontal plane around the listener whilst babble was presented continuously at 0° azimuth, and participants verbally repeated the target sentence. In a separate task, two simultaneous sentences both containing a colour and number were presented, and participants were required to report the target colour and number. Both competing sentences could originate from 0°, 20°, or 50° on the azimuthal plane. Participants also completed a series of neuropsychological assessments, an auditory questionnaire, and a three-alternative forced-choice task that involved the detection of interaural time differences (ITDs) in noise bursts. Spatial release from masking was observed in both pwMS and controls, as response accuracy in the two speech discrimination tasks improved in the spatially separated conditions (20° and 50°) compared with the co-localised condition. However, pwMS demonstrated significantly less spatial release (18%) than controls (28%) when discriminating colour/number coordinates. At 50° separation, pwMS discriminated significantly fewer coordinates (77%) than controls (89%). In contrast, pwMS had similar performances to controls when sentences were presented in babble, and for the basic ITD discrimination task. Significant correlations between speech discrimination performance and standardized neuropsychological scores were observed across all spatial conditions. Our findings suggest that spatial hearing is likely to be implicated in pwMS, thereby affecting the perception of competing speech originating from various locations.