Faculty Bibliography

BACKGROUND/OBJECTIVES/UNASSIGNED:Primary progressive aphasia (PPA) is managed with speech-language therapy (SLT) to slow language decline. Pairing transcranial direct current stimulation (tDCS) with SLT can enhance its effects. However, further research is needed to confirm these findings and guide its clinical use. We evaluated the feasibility of providing an intervention combining tDCS with SLT as a home-based and remotely supervised intervention. METHODS/UNASSIGNED:Participants with confirmed PPA who had word-finding difficulties were recruited for an open-label observational study. The intervention consisted of 20 daily sessions over 1 month, each with 45-min of personalized word retrieval training. During the first 30-min, participants received tDCS over the left inferior frontal gyrus (anode F7, cathode O1) at 2.0 mA. Language measures were remotely administered at baseline and intervention end. RESULTS/UNASSIGNED:= 0.016) from baseline to intervention end. CONCLUSIONS/UNASSIGNED:Our case series demonstrates that home-based tDCS added to SLT is feasible for patients with PPA. However, larger controlled studies are required to confirm its effectiveness in slowing language decline and to fully determine the benefits of this approach. This approach not only facilitates broader access to participation but also enables the extended treatment necessary to evaluate its clinical benefits, moving this treatment closer to clinical availability as a telehealth treatment.

OBJECTIVE/UNASSIGNED:The long-recognized association of brain injury with increased risk of dementia has undergone significant refinement and more detailed study in recent decades. Chronic traumatic encephalopathy (CTE) is a specific neurodegenerative tauopathy related to prior exposure to repetitive head impacts (RHI). We aim to contextualize CTE within a historical perspective and among emerging data which highlights the scientific and conceptual evolution of CTE-related research in parallel with the broader field of neurodegenerative disease and dementia. METHODS/UNASSIGNED:We provide a narrative state-of-the-science update on CTE neuropathology, clinical manifestations, biomarkers, different types and patterns of head impact exposure relevant for CTE, and the complicated influence of neurodegenerative co-pathology on symptoms. CONCLUSIONS/UNASSIGNED:Now almost 20 years since the initial case report of CTE in a former American football player, the field of CTE continues evolving with increasing clarity but also several ongoing controversies. Our understanding of CTE neuropathology outpaces that of disease-specific clinical correlates or the development of in-vivo biomarkers. Diagnostic criteria for symptoms attributable to CTE are still being validated, but leveraging increasingly available biomarkers for other conditions like Alzheimer's disease may be helpful for informing the CTE differential diagnosis. As diagnostic refinement efforts advance, clinicians should provide care and/or referrals to providers best suited to treat an individual patient's clinical symptoms, many of which have evidence-based behavioral treatment options that are etiologically agnostic. Several ongoing research initiatives and the gradual accrual of gold standard clinico-pathological data will pay dividends for advancing the many existing gaps in the field of CTE.

OBJECTIVE:This study aimed to externally validate the Memory Assessment Clinics Scale for Epilepsy (MAC-E), a brief self-report measure of subjective memory complaints in adults with epilepsy. METHODS:A cross-sectional study was conducted including adults with focal pharmacoresistant epilepsy from three Level 4 epilepsy centers in the U.S., who completed the MAC-E as part of a clinical neuropsychological evaluation. Confirmatory factor analysis was conducted, and goodness-of-fit criteria were calculated to assess model fit: comparative fit index (CFI), root mean square error of approximation (RMSEA), and standardized root mean residual (SRMR). Item response theory models were constructed, and Mokken analysis was used to assess discrimination and unidimensionality. Internal consistency was evaluated with McDonald's Omega. RESULTS:values for each of the 5 factors (0.58-0.91 and 0.34-0.82, respectively). MAC-E items demonstrated high levels of discrimination as well as the ability to evaluate across the entirety of each latent trait. Score responses were uniformly distributed across latent traits, and unidimensionality was established by factor (all H coefficients > 0.4). Internal consistency was high across factors (omega range: 0.77-0.88). CONCLUSIONS:Results of this study demonstrate good external validation of the MAC-E in an independent, multicenter cohort of adults with epilepsy. These findings provide further support that the MAC-E is a psychometrically valid, self-report instrument to assess every-day memory abilities in adults with epilepsy in both clinical and research settings.

OBJECTIVE:Seizures can impact cognition both acutely and chronically. However, among those without significant comorbidities and broadly average cognition at epilepsy onset, the relationship between cognitive function at the time of diagnosis and long-term seizure control has been relatively unexplored. This analysis investigated associations between participant characteristics including specific aspects of cognitive performance at the time of focal epilepsy diagnosis and antiseizure medication (ASM) treatment resistance. METHODS:This was a secondary analysis of Human Epilepsy Project (HEP) data, which enrolled people with newly diagnosed focal epilepsy and broadly average cognition (estimated IQ ≥ 70) from June 29, 2012, to September 1, 2019. Participants analyzed in this study were between 18 and 60 years old, and scored within an acceptable range (i.e., Standard Score of ≥80) on measures estimating premorbid cognitive ability were offered the Cogstate Brief Battery (CBB). Participant characteristics were analyzed, including the presence of any anxiety disorders or depression, and summary CBB scores. HEP participants who were classified by the study as treatment resistant if they had experienced failure to achieve seizure freedom after two adequate trials of ASMs. Treatment resistance was modeled using multiple logistic regression to assess for independent associations between attention and working memory after correcting for the presence of the other potentially explanatory variables. RESULTS:200 HEP participants had comprehensive enrollment records including CBB results and complete seizure outcome data for analysis in this study. After correcting for potentially confounding variables, there were no independent associations between cognitive measures on the CBB at the time of enrollment and subsequent development of ASM treatment resistance. Specifically, z-scores for reaction time on the CBB (an average of the CBB Identification and Detection tests) were not associated with treatment resistance (p = 0.51) and z-scores for memory performance (an average of the CBB One Card Learning test and One Back tests) were not associated with treatment resistance (p = 0.24). There were no significant independent associations between age or the presence of depression or anxiety disorders at the time of CBB testing and treatment resistance. However, there was an independent association between employment status and treatment resistance, with those who were employed or students (>18 years old) at the time of enrollment and CBB testing having 0.35 times lower odds of treatment resistance (95 %CI 0.15-0.81, p = 0.01). SIGNIFICANCE/CONCLUSIONS:The findings from this study suggest that in otherwise healthy people with new onset focal epilepsy who have broadly average intelligence, attention and working memory as measured by the CBB at the time of diagnosis is not associated with treatment resistance. Although performance on cognitive testing at epilepsy onset may not be predictive of risk of treatment resistance in this population, other individual characteristics such as employment status at the time of diagnosis may be indirect markers of long-term seizure outcomes and require further investigation.

Fatigue is a common and often debilitating feature of multiple sclerosis (MS) that lacks reliably effective treatment options for most patients. Transcranial direct current stimulation (tDCS), a safe and well-tolerated type of noninvasive brain stimulation, is a low-cost and home-based approach with the potential to reduce fatigue in MS. We conducted a double-blind, sham-controlled, randomized clinical trial to compare active vs. low-dose (sham) tDCS paired with computer-based cognitive training, delivered as a home-based intervention, to reduce MS-related fatigue. Participants with MS-related fatigue, but without depression, were stratified by neurologic disability using the Extended Disability Status Scale (EDSS) and randomized to complete 30 daily sessions over six weeks of either active or sham tDCS paired with online cognitive training (BrainHQ). The primary outcome was the change in PROMIS Fatigue score from baseline to the end of the intervention. A total of 117 participants were randomized, with 92% completing all treatment sessions. Both groups showed significant reductions in fatigue, with no significant difference between them. This suggests that tDCS does not provide any additional benefit over cognitive training alone in reducing fatigue, but confirms the feasibility and tolerance of this home-based intervention.

Former American football players are at risk for developing traumatic encephalopathy syndrome (TES), the clinical disorder associated with neuropathologically diagnosed chronic traumatic encephalopathy (CTE). The objective of this study was to determine whether hyposmia is present in traumatic encephalopathy syndrome. The study included 119 former professional American football players, 60 former college football players, and 58 same age asymptomatic unexposed men from the DIAGNOSE CTE Research Project. All subjects included in the analysis had completed the Brief Smell Identification Test (B-SIT). Traumatic encephalopathy syndrome and the level of CTE certainty were diagnosed using the 2021 NINDS consensus diagnostic criteria. TES is categorized antemortem by provisional levels of increasing CTE certainty: Suggestive, Possible, and Probable. Former players who had traumatic encephalopathy syndrome and Probable CTE had lower B-SIT scores than those with TES and Suggestive CTE. Hyposmia was more likely in the former players with TES who were either CTE Possible or Probable than in those who did not have TES or had TES but were less likely to have CTE, CTE Suggestive. There was no difference in B-SIT scores between all former players versus unexposed men nor overall between the football players with and without TES. We conclude that lower B-SIT scores may be a clinical biomarker for underlying CTE in former American football players.

INTRODUCTION/BACKGROUND:Blood-based biomarkers offer a promising approach for the detection of neuropathologies from repetitive head impacts (RHI). We evaluated plasma biomarkers of amyloid, tau, neurodegeneration, and inflammation in former football players. METHODS:The sample included 180 former football players and 60 asymptomatic, unexposed male participants (aged 45-74). Plasma assays were conducted for beta-amyloid (Aβ) 40, Aβ42, hyper-phosphorylated tau (p-tau) 181+231, total tau (t-tau), neurofilament light (NfL), glial fibrillary acidic protein (GFAP), interleukin-6 (IL-6), Aβ42/p-tau181 and Aβ42/Aβ40 ratios. We evaluated their ability to differentiate the groups and associations with RHI proxies and traumatic encephalopathy syndrome (TES). RESULTS:= 0.008). DISCUSSION/CONCLUSIONS:Plasma p-tau181 and p-tau231, GFAP, and NfL may offer some usefulness for the characterization of RHI-related neuropathologies. HIGHLIGHTS/CONCLUSIONS:Former football players had higher plasma p-tau181 and p-tau231 and lower Aβ42/ptau-181 compared to asymptomatic, unexposed men. Younger age of first exposure was associated with increased plasma NfL and GFAP in older but not younger participants. Plasma GFAP was higher in participants with TES-CTE possible/probable compared to TES-CTE no/suggestive.

BACKGROUND/UNASSIGNED:Cognitive decline in multiple sclerosis (MS) is common, but unpredictable, and increases with disease duration. As such, early detection of cognitive decline may improve the effectiveness of interventions. To that end, the Symbol Digit Modalities Test (SDMT) is effective in detecting slow processing speed as it relates to cognitive impairment, and intraindividual variability (IIV) observed in trials assessing continuous reaction time (RT) may be a useful indicator of early cognitive changes. Here, we will assess cognitive IIV changes in adults with early MS. METHODS/UNASSIGNED:Adults with relapsing-remitting MS (RRMS), <11 years since diagnosis, were recruited nationally. Baseline and two-year follow-up assessments included Brief International Cognitive Assessment in MS (BICAMS) and Cogstate computerized tests. Intraindividual variability in RT was calculated from psychomotor tasks and data were age-normalized. RESULTS/UNASSIGNED:= 0.05) compared to the lower SDMT group, with no significant RT or BICAMS changes. CONCLUSIONS/UNASSIGNED:In early MS, higher SDMT performance at baseline is associated with less cognitive variability but may indicate susceptibility to increased variability over time, highlighting the importance of monitoring IIV for early cognitive changes.