Two cases of MT-ND5-related mitochondrial disorder misdiagnosed as seronegative neuromyelitis optica spectrum disorder.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease primarily affecting the optic nerves and spinal cord, which is usually associated with anti-aquaporin-4 antibodies. Here, we present two individuals who were negative for anti-aquaporin-4 antibodies and were initially diagnosed with seronegative NMOSD. Each patient's clinical course and radiographic features raised suspicion for an alternative disease process. Both individuals were found to have pathogenic variants of MT-ND5, encoding subunit 5 of mitochondrial complex I, ultimately leading to a revised diagnosis of a primary mitochondrial disorder. These cases illustrate the importance of biochemical and genetic testing in atypical cases of NMOSD.

Depression symptoms and cognition in multiple sclerosis: Longitudinal evidence of a specific link to executive control.

BACKGROUND: Depression symptoms are prevalent in multiple sclerosis (MS) and associated with poorer cognition in cross-sectional studies; it is unknown whether changes in depression symptoms track with cognitive changes longitudinally. OBJECTIVE: Investigate whether changes in depression symptoms correspond with cognitive changes over time in MS, and identify specific cognitive functions related to depression symptoms. METHOD: Persons with early relapse-onset MS (n = 165) completed a depression questionnaire (Beck Depression Inventory FastScreen) and tests of cognitive speed, executive control, and memory at baseline and 3-year follow-up. One-way ANOVAs assessed differences in cognitive change across participants with worsened, stable, or improved depression symptoms from baseline to year 3. RESULTS: Change in depression symptoms was related to change in executive control (p = 0.001, ηp2 = 0.08; worsened mood with worsened executive control; improved mood with improved executive control), even when adjusting for cognitive speed (p = 0.002, ηp2 = 0.08). There were no links to cognitive speed (p = 0.826) or memory (p = 0.243). Regarding individual depression symptoms, executive control was related to loss of pleasure and suicidal thoughts. CONCLUSIONS: Executive control tracks with depression symptoms, raising hope that management of mood may improve executive control. The specific link between executive control and anhedonia implicates dysfunctional reward processing as a key component of MS depression.

Compassionate-use pocapavir and immunoglobulin therapy for treatment of rituximab-associated enterovirus meningoencephalitis.

A 71-year-old woman previously on rituximab treatment for rheumatoid arthritis presented with 2 years of progressive neurologic symptoms. She was found to have persistent hypogammaglobulinemia and B cell depletion despite rituximab discontinuation a year prior. MRI revealed diffuse meningeal enhancement along the entire neuroaxis. LP showed a CSF lymphocytic pleocytosis, elevated protein, and presence of enterovirus by PCR. The patient was hospitalized several times for progressive clinical and radiologic decline, though she had transient improvements following treatment with immunoglobulin therapy. Her CSF remained positive for enterovirus PCR for at least 12 months. Though two brain biopsies were non-diagnostic, pan-Enterovirus was ultimately identified using a high-throughput next-generation sequencing technique. She was treated with compassionate-use pocapavir with clinical stabilization at 4-month follow-up; however, she expired 8 months later from a bacterial pneumonia.

Diagnosis concealment is associated with psychosocial outcomes in persons with multiple sclerosis.

Persons with multiple sclerosis (pwMS) frequently conceal their diagnosis, fearing professional and personal repercussions of disclosing. Associations of concealment behavior and expected consequences of disclosure with psychosocial outcomes were examined in 90 pwMS who completed validated self-report measures of diagnosis concealment, loneliness, social support, and self-efficacy. More frequent concealment was related to worse loneliness (rp = 0.213, p = 0.045) and lower social support (rp = -0.211, p = 0.047), controlling for depression. Higher anticipated negative consequences of disclosure were associated with worse loneliness (rp = 0.263, p = 0.013), lower social support (rp = -0.338, p < 0.001), and lower self-efficacy (rp = -0.350, p < 0.001). Findings hold implications for the development of psychological support strategies addressing concealment/disclosure issues and their psychosocial consequences.

Summary metrics of memory subnetwork functional connectivity alterations in multiple sclerosis.

BACKGROUND: Memory dysfunction is common in multiple sclerosis (MS); mechanistic understanding of its causes is lacking. Large-scale network resting-state functional connectivity (RSFC) is sensitive to memory dysfunction. OBJECTIVE: We derived and tested summary metrics of memory network RSFC. METHODS: Cognitive data and 3T magnetic resonance imaging (MRI) scans were collected from 235 MS patients and 35 healthy controls (HCs). Index scores were calculated as RSFC within (anteriority index, AntI) and between (integration index, IntI) dorsomedial anterior temporal and medial temporal memory subnetworks. Group differences in index expression were evaluated. Associations between index scores and memory/non-memory cognition were evaluated; relationships between T2 lesion volume (T2LV) and index scores were assessed. RESULTS: Index scores were related to memory and T2LV in MS patients, who showed marginally elevated AntI relative to HC (p = 0.06); no group differences were found for IntI. Better memory was associated with higher AntI (ß = 0.15, p = 0.018) and IntI (ß = 0.16, p = 0.014). No associations were found for non-memory cognition. Higher T2LV was associated with higher AntI and IntI; exploratory mediation analysis revealed significant inconsistent mediation, that is, higher index scores partially suppressed the negative association between T2LV and memory. CONCLUSION: Summary, within-subject metrics permit replication and circumvent challenges of traditional (incommensurate) RSFC variables to advance development of mechanistic models of memory dysfunction in MS.

Associations of social network structure with cognition and amygdala volume in multiple sclerosis: An exploratory investigation.

BACKGROUND: Humans are inherently social, biologically programmed to connect with others. Social connections are known to impact mental and physical health. OBJECTIVE: The aim of this study was to test whether social network structure is linked to cognition, mood, fatigue, and regional brain volumes in persons with multiple sclerosis (MS). METHODS: A questionnaire quantifying individual-level social network structure (size, density, effective size, and constraint), a comprehensive battery of neuropsychological tests, and magnetic resonance imaging (MRI) was administered to 51 persons with relapsing-remitting MS. Linear regressions assessed associations of network variables to cognition, depression, fatigue, and structural brain volumes. RESULTS: Higher network density and constraint, indicating stronger connections among network members, were associated with worse language functions. Conversely, larger network effective size, a measure of non-redundant network members, was associated with better language functions. No relationships of network structure to depression or fatigue were found. Larger network size was related to larger amygdala volume. CONCLUSION: Findings suggest that social network structure is linked to language function and amygdala volume in persons with MS. Patients with close-knit networks showed worse language function than those with open networks. Longitudinal studies with larger samples are warranted to evaluate potential causal links between social network structure and MS-related cognitive impairment.

Feasibility trial of a telehealth support group intervention to reduce anxiety in multiple sclerosis.

OBJECTIVE: Anxiety is common among persons with MS (PwMS), but widely accepted treatments are lacking. Group-based interventions delivered via telehealth are an accessible treatment option requiring clinical trial evidence to support feasibility and initial efficacy. We conducted a pilot feasibility trial of an online support group intervention to reduce anxiety in PwMS. METHODS: A non-randomized, parallel arm clinical trial was conducted. A total of 31 PwMS were enrolled: 20 completed a 12-week telehealth-delivered support group intervention and 11 were assigned to a survey-only control group. Primary feasibility outcomes were adherence and completion rates. Primary efficacy outcome was anxiety, secondary outcomes were depression, loneliness, distress, self-efficacy, stress, and quality of life. RESULTS: Twenty-six participants completed the study. Intervention group adherence (75%) and completion (85%) rates were acceptable. Results indicated a medium size between-group effect, suggesting a greater reduction in anxiety in the intervention group compared to the control group [U = 39.50, p = 0.045, r = 0.39]. No group differences in other outcomes were observed. CONCLUSION: A telehealth-delivered support group intervention appears feasible for further study and shows initial efficacy for the reduction of anxiety in PwMS.

Phase 2 Trial of Ibudilast in Progressive Multiple Sclerosis.

BACKGROUND: There are limited treatments for progressive multiple sclerosis. Ibudilast inhibits several cyclic nucleotide phosphodiesterases, macrophage migration inhibitory factor, and toll-like receptor 4 and can cross the blood-brain barrier, with potential salutary effects in progressive multiple sclerosis. METHODS: We enrolled patients with primary or secondary progressive multiple sclerosis in a phase 2 randomized trial of oral ibudilast (≤100 mg daily) or placebo for 96 weeks. The primary efficacy end point was the rate of brain atrophy, as measured by the brain parenchymal fraction (brain size relative to the volume of the outer surface contour of the brain). Major secondary end points included the change in the pyramidal tracts on diffusion tensor imaging, the magnetization transfer ratio in normal-appearing brain tissue, the thickness of the retinal nerve-fiber layer, and cortical atrophy, all measures of tissue damage in multiple sclerosis. RESULTS: Of 255 patients who underwent randomization, 129 were assigned to ibudilast and 126 to placebo. A total of 53% of the patients in the ibudilast group and 52% of those in the placebo group had primary progressive disease; the others had secondary progressive disease. The rate of change in the brain parenchymal fraction was -0.0010 per year with ibudilast and -0.0019 per year with placebo (difference, 0.0009; 95% confidence interval, 0.00004 to 0.0017; P=0.04), which represents approximately 2.5 ml less brain-tissue loss with ibudilast over a period of 96 weeks. Adverse events with ibudilast included gastrointestinal symptoms, headache, and depression. CONCLUSIONS: In a phase 2 trial involving patients with progressive multiple sclerosis, ibudilast was associated with slower progression of brain atrophy than placebo but was associated with higher rates of gastrointestinal side effects, headache, and depression. (Funded by the National Institute of Neurological Disorders and Stroke and others; NN102/SPRINT-MS ClinicalTrials.gov number, NCT01982942 .).

Hippocampal volume is more related to patient-reported memory than objective memory performance in early multiple sclerosis.

BACKGROUND: When persons with multiple sclerosis (MS) report memory decline but objective memory performance is normal, there is a bias toward believing objective test results. OBJECTIVE: Investigate whether subjective memory decline or objective memory performance is more related to hippocampal and hippocampal subfield volumes in early MS. METHODS: Persons with early MS (n = 185; ⩽5.0 years diagnosed) completed a subjective memory questionnaire; an objective memory composite was derived from four memory tests. Total hippocampal and subfield volumes were derived from high-resolution 3.0 T magnetic resonance images (MRIs). Partial correlations assessed links between hippocampal volumes and both subjective and objective memory, controlling for age, sex, mood, and pre-morbid intelligence quotient (IQ). RESULTS: Lower total hippocampal and CA1 volumes were related to worse subjective memory but not objective memory (controlling for multiple comparisons). Correlations between subjective memory and both CA1 and subiculum were significantly stronger than were correlations between objective memory and these subfields. Patients in the worst tertile of subjective memory complaints (but not objective memory) had lower hippocampal volumes than 35 demographically similar healthy controls. CONCLUSION: Patient-report is inherently a longitudinal assessment of within-person memory change in everyday life, which may be more sensitive to subtle disease-related changes than cross-sectional objective tests. Findings align with the aging literature.

Depression and cognitive function in early multiple sclerosis: Multitasking is more sensitive than traditional assessments.

BACKGROUND: Persons with multiple sclerosis (MS) and depression symptoms report real-world cognitive difficulties that may be missed by laboratory cognitive tests. OBJECTIVE: To examine the relationship of depressive symptoms to cognitive monotasking versus multitasking in early MS. METHOD: Persons with early MS (n = 185; ⩽5 years diagnosed) reported mood, completed monotasking and multitasking cognitive tests, and received high-resolution 3.0 T magnetic resonance imaging (MRI). Partial correlations analyzed associations between mood and cognition, controlling for age, sex, estimated premorbid IQ, T2 lesion volume, and normalized gray matter volume. RESULTS: Depression symptoms were more related to worse cognitive multitasking (-0.353, p < 0.001) than monotasking (r = -0.189, p = 0.011). There was a significant albeit weaker link to cognitive efficiency composite score (r = -0.281, p < 0.001), but not composite memory (r = -0.036, p > 0.50). Findings were replicated with a second depression measure. Multitasking was worse in patients with at least mild depression than both patients with no/minimal depression and healthy controls. Multitasking was not related to mood in healthy controls. CONCLUSIONS: Depression symptoms are linked to cognitive multitasking in early MS; standard monotasking cognitive assessments appear less sensitive to depression-related cognition. Further investigation should determine directionality and mechanisms of this relationship, with the goal of enhancing treatment for cognitive dysfunction and depression in MS.

Classifying multiple sclerosis patients on the basis of SDMT performance using machine learning.

OBJECTIVE: To build a model to predict cognitive status reflecting structural, functional, and white matter integrity changes in early multiple sclerosis (MS). METHODS: Based on Symbol Digit Modalities Test (SDMT) performance, 183 early MS patients were assigned "lower" or "higher" performance groups. Three-dimensional (3D)-T2, T1, diffusion weighted, and resting-state magnetic resonance imaging (MRI) data were acquired in 3T. Using Random Forest, five models were trained to classify patients into two groups based on 1-demographic/clinical, 2-lesion volume/location, 3-local/global tissue volume, 4-local/global diffusion tensor imaging, and 5-whole-brain resting-state-functional-connectivity measures. In a final model, all important features from previous models were concatenated. Area under the receiver operating characteristic curve (AUC) values were calculated to evaluate classifier performance. RESULTS: The highest AUC value (0.90) was achieved by concatenating all important features from neuroimaging models. The top 10 contributing variables included volumes of bilateral nucleus accumbens and right thalamus, mean diffusivity of left cingulum-angular bundle, and functional connectivity among hubs of seven large-scale networks. CONCLUSION: These results provide an indication of a non-random brain pattern mostly compromising areas involved in attentional processes specific to patients who perform worse in SDMT. High accuracy of the final model supports this pattern as a potential neuroimaging biomarker of subtle cognitive changes in early MS.

A retrospective review of the long term clinical outcomes of patients with neurogenic lower urinary tract dysfunction following transverse myelitis.

AIMS: Transverse myelitis (TM) is an inflammation of the spinal cord which causes neurological deficit in motor, sensory, and autonomic pathways. Persistent neurogenic lower urinary tract dysfunction (NLUTD) is common even where motor and sensory impairment is recovered. Long term follow-up is required to ensure optimal bladder management and protection of the upper tracts. We describe the clinical outcomes for a cohort of patients with TM who have received neurourological follow-up in a specialist center. METHODS: A retrospective review of TM patient records was performed. Current pharmaceutical and surgical management, upper tract status, and patient reported symptoms are reported. Changes in urodynamic parameters and bladder emptying technique between current and baseline were analyzed. RESULTS: Sixty patients with NLUTD following TM were identified. The mean age at onset of NLUTD was 29 years (0-77 years). The mean follow-up was 13 years. 55% of patients were taking antimuscarinic medication, 53% of patients had intradetrusor botulinum toxin injections and 5% had bladder augmentation surgery. Forty-one patients had a baseline and recent urodynamic study which could be compared. Fifty-three of fifty-eight patients with a recent renal ultrasound had normal renal appearance. Four had mild hydronephrosis and one more extensive hydronephrosis. CONCLUSION: TM can have a persistent effect on lower urinary tract function. There is potential for upper tract damage if bladder management is not optimized. We have demonstrated that in a specialist neurourology unit within a tertiary center, one can provide acceptable long term outcomes following international guidelines.

eSupport: Feasibility trial of telehealth support group participation to reduce loneliness in multiple sclerosis.

BACKGROUND: Loneliness is a risk factor for increased morbidity and mortality. Persons with multiple sclerosis (pwMS) are at increased risk for loneliness. Support groups facilitate meaningful social connections. OBJECTIVE: To conduct a feasibility trial of eSupport: online support groups. METHODS: Participants engaged in 1 hour/week eSupport or eJournal (active control). Primary outcome was feasibility (completion and adherence). We evaluated loneliness and depressive symptoms for preliminary efficacy. RESULTS: Feasibility outcomes were met: completion rate was 96.4%; 88.9% were adherent. Loneliness and depression showed trend-level decreases in both conditions. CONCLUSION: Feasibility of telehealth support group participation for pwMS was supported. eSupport is accessible, affordable, acceptable, and scalable. Results warrant a randomized controlled trial to support efficacy.

Psychological resilience is linked to motor strength and gait endurance in early multiple sclerosis.

BACKGROUND: Psychologically resilient persons persist despite obstacles and bounce back after adversity, leading to better outcomes in non-neurologic populations. It is unknown whether psychological resilience relates to objective functional outcomes in multiple sclerosis (MS). OBJECTIVE: To determine whether psychological resilience explains differential objective cognitive and motor functioning in persons with early MS. METHODS: Psychological resilience was assessed in 185 patients with early MS and 50 matched healthy controls with the Connors-Davidson Resilience Scale (CDRS-10). Subjects completed the MS Functional Composite (MSFC) and a comprehensive neurobehavioral evaluation. Correlations assessed links between CDRS-10 and MSFC, motor indices (Total, Fine Motor, Gross Motor), and cognitive indices (Total, Cognitive Efficiency, Memory). RESULTS: Higher CDRS-10 among patients was linked to better MSFC and motor outcomes (but not cognition), with the most robust relationships for gross motor function (grip strength, gait endurance). Findings were independent of mood and fatigue. CDRS-10 was unrelated to MS disease burden. CDRS-10 was also specifically linked to motor outcomes in healthy controls. CONCLUSION: Functional outcomes vary across persons with MS, even when disease burden and neurologic disability are low. These findings identify high psychological resilience as a non-disease-specific contributor to motor strength and endurance, which may explain differential outcomes across patients.

Dissociable cognitive patterns related to depression and anxiety in multiple sclerosis.

BACKGROUND: Individuals with multiple sclerosis (MS) frequently present with depression and anxiety, as well as cognitive impairment, challenging clinicians to disentangle interrelationships among these symptoms. OBJECTIVE: To identify cognitive functions associated with anxiety and depression in MS. METHODS: Mood and cognition were measured in 185 recently diagnosed patients (Reserve Against Disability in Early Multiple Sclerosis (RADIEMS) cohort), and an independent validation sample (MEM CONNECT cohort, n = 70). Partial correlations evaluated relationships of cognition to anxiety and depression controlling for age, sex, education, and premorbid verbal intelligence. RESULTS: In RADIEMS cohort, lower anxiety was associated with better nonverbal memory (rp = -0.220, p = 0.003) and lower depression to better attention/processing speed (rp = -0.241, p = 0.001). Consistently, in MEM CONNECT cohort, lower anxiety was associated with better nonverbal memory (rp = -0.271, p = 0.028) and lower depression to better attention/processing speed (rp = -0.367, p = 0.002). Relationships were unchanged after controlling for T2 lesion volume and fatigue. CONCLUSION: Consistent mood-cognition relationships were identified in two independent cohorts of MS patients, suggesting that cognitive correlates of anxiety and depression are separable. This dissociation may support more precise models to inform treatment development. Treatment of mood symptoms may mitigate effects on cognition and/or treatment of cognition may mitigate effects on mood.

Word-finding difficulty is a prevalent disease-related deficit in early multiple sclerosis.

BACKGROUND: Persons with multiple sclerosis (MS) commonly report word-finding difficulty clinically, yet this language deficit remains underexplored. OBJECTIVE: To investigate the prevalence and nature of word-finding difficulty in persons with early MS on three levels: patient report, cognitive substrates, and neuroimaging. METHODS: Two samples of early MS patients (n = 185 and n = 55; ⩽5 years diagnosed) and healthy controls (n = 50) reported frequency/severity of cognitive deficits and underwent objective assessment with tasks of rapid automatized naming (RAN), measuring lexical access speed, memory, word generation, and cognitive efficiency. High-resolution brain magnetic resonance imaging (MRI) derived measurements of regional cortical thickness, global and deep gray matter volume, and T2 lesion volume. Relationships among patient-reported word-finding difficulty, cognitive performance, and neural correlates were examined. RESULTS: Word-finding difficulty was the most common cognitive complaint of MS patients and the only complaint reported more by patients than healthy controls. Only RAN performance discriminated MS patients with subjective word-finding deficits from those without subjective complaints and from healthy controls. Thinner left parietal cortical gray matter independently predicted impaired RAN performance, driven primarily by the left precuneus. CONCLUSION: Three levels of evidence (patient-report, objective behavior, regional gray matter) support word-finding difficulty as a prevalent, measurable, disease-related deficit in early MS linked to left parietal cortical thinning.

Impact of the COVID-19 Pandemic on the Personal Networks and Neurological Outcomes of People With Multiple Sclerosis: Cross-Sectional and Longitudinal Case-Control Study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has negatively affected the social fabric. OBJECTIVE: We evaluated the associations between personal social networks and neurological function in people with multiple sclerosis (pwMS) and controls in the prepandemic and pandemic periods. METHODS: During the early pandemic (March-December 2020), 8 cohorts of pwMS and controls completed a questionnaire quantifying the structure and composition of their personal social networks, including the health behaviors of network members. Participants from 3 of the 8 cohorts had additionally completed the questionnaire before the pandemic (2017-2019). We assessed neurological function using 3 interrelated patient-reported outcomes: Patient Determined Disease Steps (PDDS), Multiple Sclerosis Rating Scale-Revised (MSRS-R), and Patient-Reported Outcomes Measurement Information System (PROMIS) Physical Function. We identified the network features associated with neurological function using paired 2-tailed t tests and covariate-adjusted regressions. RESULTS: In the cross-sectional analysis of the pandemic data from 1130 pwMS and 1250 controls during the pandemic, having a higher percentage of network members with a perceived negative health influence was associated with worse disability in pwMS (MSRS-R: ß=2.181, 95% CI 1.082-3.279; P<.001) and poor physical function in controls (PROMIS Physical Function: ß=-5.707, 95% CI -7.405 to -4.010; P<.001). In the longitudinal analysis of 230 pwMS and 136 controls, the networks of all participants contracted, given an increase in constraint (pwMS-prepandemic: mean 52.24, SD 15.81; pwMS-pandemic: mean 56.77, SD 18.91; P=.006. Controls-prepandemic: mean 48.07, SD 13.36; controls-pandemic: mean 53.99, SD 16.31; P=.001) and a decrease in network size (pwMS-prepandemic: mean 8.02, SD 5.70; pwMS-pandemic: mean 6.63, SD 4.16; P=.003. Controls-prepandemic: mean 8.18, SD 4.05; controls-pandemic: mean 6.44, SD 3.92; P<.001), effective size (pwMS-prepandemic: mean 3.30, SD 1.59; pwMS-pandemic: mean 2.90, SD 1.50; P=.007. Controls-prepandemic: mean 3.85, SD 1.56; controls-pandemic: mean 3.40, SD 1.55; P=.01), and maximum degree (pwMS-prepandemic: mean 4.78, SD 1.86; pwMS-pandemic: mean 4.32, SD 1.92; P=.01. Controls-prepandemic: mean 5.38, SD 1.94; controls-pandemic: mean 4.55, SD 2.06; P<.001). These network changes were not associated with worsening function. The percentage of kin in the networks of pwMS increased (mean 46.06%, SD 29.34% to mean 54.36%, SD 30.16%; P=.003) during the pandemic, a change that was not seen in controls. CONCLUSIONS: Our findings suggest that high perceived negative health influence in the network was associated with worse function in all participants during the pandemic. The networks of all participants became tighter knit, and the percentage of kin in the networks of pwMS increased during the pandemic. Despite these perturbations in social connections, network changes from the prepandemic to the pandemic period were not associated with worsening function in all participants, suggesting possible resilience.

A randomized controlled trial of oral antipyretic treatment to reduce overheating during exercise in adults with multiple sclerosis.

BACKGROUND: Some people with multiple sclerosis (pwMS) avoid exercise due to overheating. Evidence from a variety of cooling treatments shows benefits for pwMS. OBJECTIVE: Conduct a randomized controlled trial of antipyretic treatment before exercise in pwMS. METHODS: Adults over age 18 diagnosed with relapsing-remitting MS reporting heat sensitivity during exercise were randomly assigned to one of six sequences counterbalancing aspirin, acetaminophen, placebo. At each of three study visits separated by ≥ one week, participants received 650-millograms of aspirin, acetaminophen, or placebo before completing a maximal exercise test. Primary outcomes were body temperature change and total time-to-exhaustion (TTE), secondary outcomes were physiological and patient-reported outcomes (PROs). RESULTS: Sixty participants were enrolled and assigned to treatment sequence; 37 completed ≥ one study visit. After controlling for order effects, we found that body temperature increase was reduced after aspirin (+ 0.006 ± 0.32 degrees Fahrenheit, p < 0.001) and after acetaminophen (+ 0.31 ± 0.35; p = 0.004) compared to placebo (+ 0.68 ± 0.35). TTE after aspirin (331.6 ± 76.6 s) and acetaminophen (578.2 ± 82.1) did not differ significantly from placebo (551.0 ± 78.4; p's > 0.05). Aspirin benefited all secondary outcomes compared to placebo (all p's < 0.001); acetaminophen showed broadly consistent benefits. CONCLUSION: These results support antipyretic treatment as effective for reducing overheating during exercise in pwMS and failed to support antipyretics for increasing TTE in the context of a maximal exercise test. Benefits were shown for physiological markers of exercise productivity and PROs of fatigue, pain, and perceived exertion.