Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:The link between repetitive head impact (RHI) exposure, later-life cognitive decline, and neurobehavioral dysregulation (NBD) is not well understood. Recent work has implicated inflammation and limbic dysfunction as relevant RHI correlates. Our goal was to integrate plasma and CSF inflammatory biomarkers, structural brain imaging, and clinical measures in former elite American football players to better understand reasons for RHI-related cognitive and neurobehavioral changes. METHODS: RESULTS: DISCUSSION/CONCLUSIONS:In former elite football players, elevated plasma and CSF inflammatory markers were associated with poorer limbic WM microstructure, which in turn related to worse cognition. Given the limbic system's role in cognition and behavior, inflammation may be a modifiable target for RHI-related neurodegeneration. Limitations include the cross-sectional design and limited generalizability to other contact sports, lower levels of play, female athletes, or other RHI sources.

OBJECTIVE:Subjective cognitive complaints (SCC) can precede cognitive decline and are associated with demographic, exposure, lifestyle, and psychological factors. Prevalences of SCC and their correlates in individuals with repetitive head impacts (RHI) are poorly understood. This study characterized SCC in former elite American football players by frequency, mood and behavioral correlates, concordance with informant reports, and associations with neuropsychological test performance, cerebrospinal fluid (CSF), and magnetic resonance imaging (MRI) markers of neurodegeneration. METHOD/METHODS:, t-tau, neurofilament light (NfL), hippocampal volume, and regional cortical thickness were examined for their potential associations with SCC. RESULTS:ϵ4 carrier status, and depressive symptoms, SCC were associated with lower objective verbal memory and executive functioning performance. SCC were associated with lower parahippocampal cortical thickness but not with hippocampal volume or any of the measured CSF tests. CONCLUSIONS:SCC are strongly associated with neuropsychiatric factors in former American football players. SCC may also be a marker of cognitive decline and neurodegeneration.

IMPORTANCE/UNASSIGNED:Treatment for cognitive dysfunction due to postacute sequelae of long COVID (ie, symptoms of fatigue, malaise, weakness, confusion that persist beyond 12 weeks after an initial COVID infection) remains a significant unmet need. OBJECTIVE/UNASSIGNED:To test evidence-based rehabilitation strategies for improving cognitive symptoms in persons with long COVID. DESIGN, SETTING, AND PARTICIPANTS/UNASSIGNED:This was a 5-arm, multicenter, randomized clinical trial of 3 remotely delivered interventions conducted between August 17, 2023, and June 10, 2024. The study took place at 22 trial sites and included the screening of individuals with cognitive long COVID. INTERVENTIONS/UNASSIGNED:Participants were randomized to 1 of 5 arms: adaptive computerized cognitive training (BrainHQ [Posit Science]), cognitive-behavioral rehabilitation involving both group and individual counseling sessions (PASC-Cognitive Recovery [PASC-CoRE]) paired with BrainHQ, and transcranial direct current stimulation (tDCS) paired with BrainHQ. Two comparator arms were included as follows: unstructured computer puzzles and games (active comparator) and sham tDCS paired with BrainHQ. The interventions occurred 5 times per week over 10 weeks. MAIN OUTCOMES AND MEASURES/UNASSIGNED:Cognitive and behavioral in-person assessments were performed at baseline, midintervention, at the end of intervention, and 3 months after the end of the intervention. The primary outcome measure was the modified Everyday Cognition Scale 2 (ECog2) completed at the end of the intervention compared to the baseline visit based on participant self-report looking back over the prior 7 days. RESULTS/UNASSIGNED:A total of 378 individuals were screened, from which there were 328 participants (median [IQR] age, 48.0 [37.0-58.0] years; 241 female [73.5%]; race: 15 Asian [4.6%], 47 Black [14.3%], and 235 White [71.6%]; ethnicity: 52 Hispanic [15.9%]). None of the 3 active interventions demonstrated benefits on the modified ECog2 in the intention-to-treat population by the end of the intervention period. The adjusted differences in mean change were 0.0 (95% CI, -0.2 to 0.2) for BrainHQ vs active comparator, 0.1 (95% CI, -0.1 to 0.3) for PASC-CoRE + BrainHQ vs active comparator, 0.0 (95% CI, -0.2 to 0.2) for tDCS-active + BrainHQ vs tDCS-sham + BrainHQ, and 0.1 (95% CI, -0.1 to 0.3) for PASC-CoRE + BrainHQ vs BrainHQ alone. Secondary participant-reported outcomes and neuropsychological tests showed no differential benefits for any treatment arm. All 5 arms demonstrated some improvements over time on the modified ECog2 and on secondary outcomes. There were no serious adverse events attributable to the interventions. CONCLUSIONS AND RELEVANCE/UNASSIGNED:This phase 2 randomized clinical trial failed to demonstrate differential benefits for online cognitive training, a structured cognitive rehabilitation program, and tDCS for cognitive long COVID. TRIAL REGISTRATION/UNASSIGNED:ClinicalTrials.gov Identifier: NCT05965739.

Childhood adversity is increasingly recognized as a critical modifier of neurologic disorder development and disease severity, including in the neuroimmune disorder multiple sclerosis (MS). While previous studies have linked early-life adversity to increased MS susceptibility and more severe disease, the underlying biological mechanisms remain poorly understood. This study investigated associations between childhood adversity and MS clinical features, with a focus on two potential pathogenic mechanisms: allostatic load and epigenetic modifications. We evaluated 60 consecutively enrolled young adults with MS; 30 with paediatric-onset MS (POMS) and 30 with adult-onset MS (AOMS). At time of enrolment in this cross-sectional study, participants had MS disease duration of 6 years on average. POMS participants were mean 22.09 (2.66) years and AOMS participants were mean 32.41 (2.19) years old. 62% of participants were female. Childhood adversity was defined using a composite index of individual, family and socioeconomic measures captured by the adverse childhood experiences questionnaire, parental education level and estimated household income during childhood. Clinical outcomes included patient-reported SymptoMScreen questionnaire regarding MS symptom burden and MS neurologist-assessed disability using the Expanded Disability Status Scale (EDSS) of the participant's neurologic exam at the time of enrolment. Circulating biomarkers of allostatic load and genome-wide epigenetic profiles (DNA methylation via RRBS; reduced representation bisulfite sequencing) were also assessed. A history of high childhood adversity was associated with significantly greater patient-reported MS symptom burden (P = 0.001) and higher neurologist-reported EDSS disability scores (P = 0.028), independent of disease duration or timing of treatment initiation. There were no differences between childhood adversity and circulating biomarkers of allostatic load. While childhood adversity was not associated with global epigenetic changes across the entire cohort, stratified analysis revealed divergent methylation patterns by age of MS onset: POMS participants with childhood adversity had increased DNA methylation, whereas AOMS participants with childhood adversity showed decreased methylation compared to individuals without childhood adversity. None of the observed clinical and biologic differences were explained by differences in disease duration or the interval between symptom onset and treatment initiation. Our findings suggest that childhood adversity is associated with increased MS symptom burden and neurologic disability in young adults with MS. Childhood adversity may differentially shape the epigenome, depending on the age of MS onset, with potential implications for disease trajectory and therapeutic vulnerability. These results support the biological embedding of childhood adversity in MS and highlight the need for age- and exposure-sensitive approaches to understanding MS pathogenesis across the lifespan.

BACKGROUND:In vivo biomarkers that can detect long-term neuropathologies from repetitive head impact (RHI) exposure are needed, especially for the neurodegenerative tauopathy chronic traumatic encephalopathy (CTE). Here, we evaluated plasma p-tau217 as a potential biomarker for CTE p-tau pathology, and examined the concordance between plasma p-tau217 and Aβ pathology in an at-risk for CTE sample. METHOD/METHODS:The sample included 180 male former football players (120 professional, 60 college), and 56 asymptomatic men without RHI (i.e., controls). Participants completed blood draws, 18F-florbetapir (Aβ+=SUVR≥1.10), and 18F-flortaucipir PET. Traumatic encephalopathy syndrome (TES) diagnoses were made. Single molecule array for plasma p-tau217 (ALZpath) was performed (≥0.6 cutoff used to maximize sensitivity). Nine participants had post-mortem tissue. ANCOVA examined group differences in p-tau217 (football vs controls; TES-CTE no, TES-CTE suggestive, TES-CTE possible/probable). Multivariable regression models tested associations between p-tau217 and florbetapir/flortaucipir PET. Covariates included age, race and APOE e4. RESULT/RESULTS:Sample characteristics are in Table 1. p-tau217 concentrations were higher in former football players compared to controls (est. marginal mean difference=-0.217, p = 0.005). There were no group differences in Aβ-PET SUVR. No differences were found across TES-CTE certainty levels. In football players, higher p-tau217 was associated with higher Aβ-PET SUVR (B=1.380, 95%CI[0.597-2.155], p = 0.001) but not when Aβ+ (n = 17) participants and those with kidney/liver disease (n = 5) were excluded. Aβ+ participants had the highest p-tau217 (Figure 1). When compared against Aβ-PET, several false Aβ-positives (high p-tau217, Aβ-) were identified, including one extreme outlier (assay related) and a cluster of Aβ- participants with p-tau217 between 0.60-1.0. There were no associations with flortaucipir SUVR (frontal, mesial temporal, left parietal). Two extreme p-tau217 outliers had autopsy-confirmed CTE stage III (AD-, Table 2). Of the remaining donors, all were AD- and four had CTE (stages II-IV) with ptau217 between 0.125-0.449. CONCLUSION/CONCLUSIONS:Plasma p-tau217 has usefulness in quantifying Aβ pathology but restricted utility for detection of CTE. In this at-risk for CTE sample, p-tau217 and Aβ-PET were associated at the group level. At the individual level, false Aβ-positives (and negatives) existed, including Aβ- participants with high p-tau217. We will explore whether this discrepancy is due to disease or peripheral interference with the N-terminal binding in p-tau assays.

This guideline summarizes updated safety data (2017-2025) and provides expert recommendations on the use of low intensity transcranial electrical stimulation (tES) in humans. tES encompasses several techniques including transcranial direct current stimulation (tDCS), oscillatory transcranial direct current stimulation (otDCS), transcranial alternating current stimulation (tACS), transcranial random noise stimulation (tRNS), transcranial temporal interference stimulation (tTIS), and their combinations or variations. Across over 300,000 sessions involving healthy individuals, patients with neuropsychiatric conditions, and other clinical populations, no tES-related serious adverse events (AEs) have been reported. Moderate AEs are rare and limited to a small range of specific applications. Mild AEs are common and include transient symptoms such as localized sensations (e.g., tingling or burning), headaches, and fatigue. Similar mild AEs are also reported by individuals receiving placebo stimulation. The frequency, magnitude, and type of AEs are comparable across healthy, clinical, and vulnerable groups, including children, elderly, or pregnant women. Combined interventions (e.g., co-application with EEG, TMS, or neuroimaging) have not shown increased safety risks. Safety is well-established for both bipolar and multichannel tES when applied up to 4 mA and up to 60 min per day. Higher intensities and longer stimulation durations may also be safe. Nevertheless, the number of studies using intensities above 4 mA or stimulating longer than 60 min is low. Home-based use of treatments is growing rapidly, leveraging remote supervision to provide patients with greater access and enable repeated, sustained dosing paradigms. We recommend using screening and AE questionnaires in future controlled studies, in particular when planning to extend the stimulation parameters applied. We discuss recent regulatory and ethical issues.

OBJECTIVE:To assess real-world effectiveness of switching disease-modifying therapy (DMT) in pediatric multiple sclerosis (MS) and clinically isolated syndrome (CIS) initially treated with platform injectables on disease activity. METHODS:Of 2615 pediatric-onset demyelinating disease patients at 12 clinics in the United States (US) Network of Pediatric MS Centers, those with MS/CIS on initial therapy with a platform injectable who switched to another class of platform injectable, oral or infusion DMT were analyzed. Relapse rate was modeled with negative binomial regression, adjusted for preidentified confounders. RESULTS:A total of 212 children switched DMT before age 18 (67% female, 95% MS). Ninety-three switched from injectable to injectable, 76 injectable to oral, and 43 injectable to infusion. Switchers to oral or infusion were older at onset (injectable 12.3 years, oral 13.5 years, and infusion 14.2 years) and switch (injectable 14.6 years, oral 16.0 years, and infusion 15.7 years). Switchers to infusion DMT were more likely to have enhancing lesions (injectable 45%, oral 28%, and infusion 67%). Compared to injectable (annualized relapse rate [ARR] = 0.88, 95% confidence interval [CI] = 0.52-1.48), relapse rates were lower for injectable to oral (ARR = 0.34, 95% CI = 0.20-0.57; rate ratio: 0.38, 95% CI = 0.21-0.69) and injectable to infusion (ARR = 0.18, 95% CI = 0.09-0.37; rate ratio: 0.21, 95% CI = 0.10-0.44) (p < 0.001). Adjusted number needed to treat in person-years to prevent 1 relapse with oral over injectable was 1.84 (95% CI = 1.03-8.69) and infusion over injectable 1.43 (95% CI = 1.00-3.88). INTERPRETATION/CONCLUSIONS:Switching from platform injectable to oral or infusion compared to other platform injectable DMT led to better disease control in pediatric MS. Long-term safety data are required. ANN NEUROL 2025.

OBJECTIVE:People with focal epilepsy experience one or more seizures prior to diagnosis. The Human Epilepsy Project (HEP) was a prospective study enrolling people with newly diagnosed focal epilepsy. It collected information including cognitive testing at the time of enrollment. This was completed utilizing a computerized test battery called the Cogstate Brief Battery (CBB). A prior analysis found that enrollment CBB test scores were below that of age matched controls and that performance on testing was not independently associated with the longer-term development of treatment resistance over the course of the HEP study. The present study assesses the impact of pretreatment seizures on cognition at time of diagnosis, considering time-to-treatment initiation in relation to seizure onset, pre-treatment seizure frequency, and pretreatment seizure classification. METHODS:Participants with newly diagnosed focal epilepsy and no other major medical comorbidities or intellectual disability (estimated IQ > 70) were enrolled between June 29, 2012, and September 1, 2019. A subset of the 448 enrolled participants (N = 183) were over 18 years old, had complete HEP enrollment data that included pre-treatment seizure histories, and complete enrollment CBB testing for analysis in this study. Performance on enrollment CBB testing was modeled using multiple linear regression with pre-treatment seizure characteristics including seizure type and duration between seizure onset and treatment initiation, controlling for other key baseline participant characteristics. RESULTS:There were no independent associations between cognitive measures on the CBB at the time of enrollment and pre-treatment seizures after correcting for potentially confounding variables. Z-scores for the attention composite on CBB (an average of Identification and Detection tests) were not associated with a global pre-treatment seizure score that quantified time with seizures (days) and seizure count by seizure type (motor, non-motor, bilateral tonic clonic) (p = 0.29). Similarly, z-scores for the memory composite (an average of the One Card Learning test and One Back tests) were not associated with the pre-treatment seizure score (p = 0.1). No additional independent associations were found to be significant between z-scores for attention or memory composites and other potential explanatory variables. SIGNIFICANCE/CONCLUSIONS:This study highlights an important finding for people who develop focal epilepsy and otherwise are in good health: pre-treatment time-limited seizures do not have an independent impact on cognition early on, as measured by a brief validated cognitive screening test. This suggests that that cognition at the time of epilepsy diagnosis may be more strongly related to underlying etiology, chronic disease, and comorbidities.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Pediatric multiple sclerosis (MS) affects children and adolescents at an important time for neurologic and cognitive development. Although cognitive impairment has been described, few longitudinal studies of cognitive functioning in pediatric MS with matched controls are available. Here, we report the 2-year follow-up cognitive results of a cohort of participants with MS and healthy controls (HCs) recruited from multiple regions of the United States. METHODS:Three cohorts-participants with pediatric MS, age-matched pediatric HC, and adults with early-onset MS-were recruited across 7 sites through the United States Network of Pediatric MS Centers. Two cognitive batteries, Cogstate Brief Battery (CBB) and Brief International Cognition Assessment for MS (BICAMS), were administered at baseline and follow-up. The primary outcome was the change in CBB composite z-score compared between groups. Change in BICAMS composite z-score was also compared, as were change in z-scores of individual measures. Reliable change indices (RCIs) were calculated to determine meaningful change over time. RESULTS:= 0.022. DISCUSSION/CONCLUSIONS:Most individuals with pediatric MS early in their disease showed stable cognitive function over a 2-year period and had longitudinal changes that were largely similar to pediatric controls. A subset of participants with pediatric MS declined in cognitive processing speed relative to pediatric controls.