Faculty Bibliography

RATIONALE/BACKGROUND:The International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) was recently introduced as a consensus-based, empirically-driven taxonomy of cognitive disorders in epilepsy and has been effectively applied to patients with temporal lobe epilepsy (TLE). The purpose of this study was to apply the IC-CoDE to patients with frontal lobe epilepsy (FLE) using national multicenter data. METHODS:Neuropsychological data of 455 patients with FLE aged 16 years or older were available across four US-based sites. First, we examined test-specific impairment rates across sites using two impairment thresholds (1.0 and 1.5 standard deviations below the normative mean). Following the proposed IC-CoDE guidelines, patterns of domain impairment were determined based on commonly used tests within five cognitive domains (language, memory, executive functioning, attention/processing speed, and visuospatial ability) to construct phenotypes. Impairment rates and distributions across phenotypes were then compared with those found in patients with TLE for which the IC-CoDE classification was initially validated. RESULTS:The highest rates of impairment were found among tests of naming, verbal fluency, speeded sequencing and set-shifting, and complex figure copy. The following IC-CoDE phenotype distributions were observed using the two different threshold cutoffs: 23-40% cognitively intact, 24-29% single domain impairment, 13-20% bi-domain impairment, and 18-33% generalized impairment. Language was the most common single domain impairment (68% for both thresholds) followed by attention and processing speed (15-18%). Overall, patients with FLE reported higher rates of cognitive impairment compared with patients with TLE. CONCLUSIONS:These results demonstrate the applicability of the IC-CoDE to epilepsy syndromes outside of TLE. Findings indicated generally stable and reproducible phenotypes across multiple epilepsy centers in the U.S. with diverse sample characteristics and varied neuropsychological test batteries. Findings also highlight opportunities for further refinement of the IC-CoDE guidelines as the application expands.

OBJECTIVE:Visual assessment of magnetic resonance imaging (MRI) from the Human Epilepsy Project 1 (HEP1) found 18% of participants had atrophic brain changes relative to age without known etiology. Here, we identify the underlying factors related to brain volume differences in people with focal epilepsy enrolled in HEP1. METHODS:Enrollment data for participants with complete records and brain MRIs were analyzed, including 391 participants aged 12-60 years. HEP1 excluded developmental or cognitive delay with intelligence quotient <70, and participants reported any formal learning disability diagnoses, repeated grades, and remediation. Prediagnostic seizures were quantified by semiology, frequency, and duration. T1-weighted brain MRIs were analyzed using Sequence Adaptive Multimodal Segmentation (FreeSurfer v7.2), from which a brain tissue volume to intracranial volume ratio was derived and compared to clinically relevant participant characteristics. RESULTS:Brain tissue volume changes observable on visual analyses were quantified, and a brain tissue volume to intracranial volume ratio was derived to compare with clinically relevant variables. Learning difficulties were associated with decreased brain tissue volume to intracranial volume, with a ratio reduction of .005 for each learning difficulty reported (95% confidence interval [CI] = -.007 to -.002, p = .0003). Each 10-year increase in age at MRI was associated with a ratio reduction of .006 (95% CI = -.007 to -.005, p < .0001). For male participants, the ratio was .011 less than for female participants (95% CI = -.014 to -.007, p < .0001). There were no effects from seizures, employment, education, seizure semiology, or temporal lobe electroencephalographic abnormalities. SIGNIFICANCE/CONCLUSIONS:This study shows lower brain tissue volume to intracranial volume in people with newly treated focal epilepsy and learning difficulties, suggesting developmental factors are an important marker of brain pathology related to neuroanatomical changes in focal epilepsy. Like the general population, there were also independent associations between brain volume, age, and sex in the study population.

INTRODUCTION/BACKGROUND:The presentation, risk factors, and etiologies of white matter hyperintensities (WMH) in people exposed to repetitive head impacts are unknown. We examined the burden and distribution of WMH, and their association with years of play, age of first exposure, and clinical function in former American football players. METHODS:A total of 149 former football players and 53 asymptomatic unexposed participants (all men, 45-74 years) completed fluid-attenuated inversion recovery magnetic resonance imaging, neuropsychological testing, and self-report neuropsychiatric measures. Lesion Segmentation Toolbox estimated WMH. Analyses were performed in the total sample and stratified by age 60. RESULTS:In older but not younger participants, former football players had greater total, frontal, temporal, and parietal log-WMH compared to asymptomatic unexposed men. In older but not younger former football players, greater log-WMH was associated with younger age of first exposure to football and worse executive function. DISCUSSION/CONCLUSIONS:In older former football players, WMH may have unique presentations, risk factors, and etiologies. HIGHLIGHTS/CONCLUSIONS:Older but not younger former football players had greater total, frontal, temporal, and parietal lobe white matter hyperintensities (WMH) compared to same-age asymptomatic unexposed men. Younger age of first exposure to football was associated with greater WMH in older but not younger former American football players. In former football players, greater WMH was associated with worse executive function and verbal memory.

OBJECTIVES:Intra-individual variability (IIV), measured across repeated response times (RT) during continuous psychomotor tasks, is an early marker of cognitive change in the context of neurodegeneration. To advance IIV towards broader application in clinical research, we evaluated IIV from a commercial cognitive testing platform and compared it to the calculation approaches used in experimental cognitive studies. METHODS:-transformed standard deviation or "LSD"). We calculated IIV from the raw RTs using coefficient of variation (CoV), regression-based, and ex-Gaussian methods. The IIV from each calculation was then compared by rank across participants. RESULTS:A total of n = 120 participants with MS aged 20-72 (Mean ± SD, 48.99 ± 12.09) completed the baseline cognitive measures. For each task, the interclass correlation coefficient was generated. Each ICC showed that LSD, CoV, ex-Gaussian, and regression methods clustered strongly (Average ICC for DET: 0.95 with 95% CI [0.93, 0.96]; Average ICC for IDN: 0.92 with 95% CI [0.88 to 0.93]; Average ICC for ONB: 0.93 with 95% CI [0.90 to 0.94]). Correlational analyses indicated the strongest correlation between LSD and CoV for all tasks (rs ≥ 0.94). CONCLUSION:The LSD was consistent with research-based methods for IIV calculations. These findings support the use of LSD for the future measurement of IIV for clinical studies.

OBJECTIVE:and to assess the ability of the IC-CoDE to produce definable and stable cognitive phenotypes in a large, multi-center temporal lobe epilepsy (TLE) patient sample. METHOD/METHODS:were derived across samples using the IC-CoDE and compared to distributions of phenotypes reported in existing studies. RESULTS:Impairment rates were highest on tests of language, followed by memory, executive functioning, attention/processing speed, and visuospatial ability. Application of the IC-CoDE using varying operational definitions of impairment (≤ 1.0 and ≤ 1.5 SD) produced cognitive phenotypes with the following distribution: cognitively intact (30%-50%), single-domain (26%-29%), bi-domain (14%-19%), and generalized (10%-22%) impairment. Application of the ≤ 1.5 cutoff produced a distribution of phenotypes that was consistent across cohorts and approximated the distribution produced using data-driven approaches in prior studies. CONCLUSIONS:The IC-CoDE is the first iteration of a classification system for harmonizing cognitive diagnostics in epilepsy research that can be applied across neuropsychological tests and TLE cohorts. This proof-of-principle study in TLE offers a promising path for enhancing research collaborations globally and accelerating scientific discoveries in epilepsy. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

OBJECTIVE:This study was undertaken to evaluate the cross-cultural application of the International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) to a cohort of Spanish-speaking patients with temporal lobe epilepsy (TLE) living in the United States. METHODS:Eighty-four Spanish-speaking patients with TLE completed neuropsychological measures of memory, language, executive function, visuospatial functioning, and attention/processing speed as part of the Neuropsychological Screening Battery for Hispanics. The contribution of demographic and clinical variables to cognitive performance was evaluated. A sensitivity analysis was conducted by examining the base rates of impairment across several impairment thresholds. The IC-CoDE taxonomy was then applied, and the base rate of cognitive phenotypes for each cutoff was calculated. The distribution of phenotypes was compared to the published IC-CoDE taxonomy data, which utilized a large, multicenter cohort of English-speaking patients with TLE. RESULTS:Across the different impairment cutoffs, memory was the most impaired cognitive domain, with impairments in list learning ranging from 50% to 78%. Application of the IC-CoDE taxonomy utilizing a -1.5-SD cutoff revealed an intact cognitive profile in 47.6% of patients, single-domain impairment in 23.8% of patients, bidomain impairment in 14.3% of patients, and generalized impairment in 14.3% of the sample. This distribution was comparable to the phenotype distribution observed in the IC-CoDE validation sample. SIGNIFICANCE/CONCLUSIONS:We demonstrate a similar pattern and distribution of cognitive phenotypes in a Spanish-speaking epilepsy cohort compared to an English-speaking sample. This suggests stability in the underlying phenotypes associated with TLE and applicability of the IC-CoDE for guiding cognitive diagnostics in epilepsy research that can be applied to culturally and linguistically diverse samples.

BACKGROUND:Patterns of cognitive impairment in former American football players are uncertain because objective neuropsychological data are lacking. This study characterized the neuropsychological test performance of former college and professional football players. METHODS:One hundred seventy male former football players (n=111 professional, n=59 college; 45-74 years) completed a neuropsychological test battery. Raw scores were converted to T-scores using age, sex, and education-adjusted normative data. A T-score ≤ 35 defined impairment. A domain was impaired if 2+ scores fell in the impaired range except for the language and visuospatial domains due to the limited number of tests. RESULTS:Most football players had subjective cognitive concerns. On testing, rates of impairments were greatest for memory (21.2% two tests impaired), especially for recall of unstructured (44.7%) versus structured verbal stimuli (18.8%); 51.8% had one test impaired. 7.1% evidenced impaired executive functions; however, 20.6% had impaired Trail Making Test B. 12.1% evidenced impairments in the attention, visual scanning, and psychomotor speed domain with frequent impairments on Trail Making Test A (18.8%). Other common impairments were on measures of language (i.e., Multilingual Naming Test [21.2%], Animal Fluency [17.1%]) and working memory (Number Span Backward [14.7%]). Impairments on our tasks of visuospatial functions were infrequent. CONCLUSIONS:In this sample of former football players (most of whom had subjective cognitive concerns), there were diffuse impairments on neuropsychological testing with verbal memory being the most frequently impaired domain.

Abstract Background: Loss of hand dexterity is disabling and reduces quality of life. People living with progressive forms of MS have marked neurologic disabilities but limited rehabilitation options. Transcranial direct current stimulation (tDCS) is a method of noninvasive brain stimulation in which stimulation delivered during motor training can strengthen outcomes. We have established a remotely supervised tDCS (RS-tDCS) protocol that delivers multiple stimulation sessions paired with training to participants at home.
Objective(s): To evaluate a blinded randomized sham-controlled clinical trial of active vs. sham tDCS paired with manual dexterity training for people with progressive MS.
Method(s): We recruited right-hand dominant individuals with progressive MS and hand dexterity impairment. Participants completed 20 sessions of daily (M-F) manual dexterity and were randomized to either active (2.0 mA) or sham primary motor cortex (M1-SO) tDCS. Manual dexterity was measured with the Nine-Hole Peg Test (9HPT) and Dellon-Modified Moberg Pick-Up test (MMPUT) at baseline and study end and transformed to normative z-scores for comparison.
Result(s): Participants were n=60 with primary (32%) or secondary (68%) progressive MS (52% female, ages 37-72 years, and a median Expanded Disability Status Scale (EDSS) score of 5.0 [1.5-7.5]). The intervention was safe and well tolerated, with n=59/60 (98%) completing 18/20 daily sessions. Combining hands and tasks, the full group improved following the manual dexterity training (mean z-score improvement 1.64+/-9.53, p=0.016). Active tDCS led to greater improvement (mean z-score improvement 4.51+/-8.78, p=0.001). Analyzing those with right- or left-hand impairment at baseline, the active tDCS group had significant improvement on the 9HPT (Right: p=0.036, Left: p=0.028) and trended towards significant improvement for the MMPUT (Right: p=0.071, Left: p=0.079).
Conclusion(s): At-home manual dexterity training paired with tDCS is a safe, tolerable, and feasible intervention for people with progressive MS and hand impairment. Training outcomes are augmented with simultaneous M1-SO tDCS. Research Category and Technology and Methods Clinical Research: 9. Transcranial Direct Current Stimulation (tDCS) Keywords: tDCS, motor training, multiple sclerosis, teleintervention
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Abstract Objectives: Evaluate feasibility and preliminary efficacy of remotely supervised transcranial Direct Current Stimulation (RS-tDCS) interventions for persistent post-traumatic headache (PPTH) secondary to mild TBI (mTBI).
Method(s): Veterans with PPTH completed a 28-day baseline observation of headache days and received either active or sham RS-tDCS paired with mindfulness meditation. This 4-week intervention of 20-minutes daily (M-F) RS-tDCS (anodal stimulation dlPFC) was monitored via VA Video Connect. Feasibility was determined by the number of participants completing >=80% of the intervention. Efficacy was measured by changes in number of moderate/severe headache days from baseline period to the end of treatment phase, and 4-week post-treatment follow-up. Secondary endpoints included total number of headache days, acute pain medication use, as well as headache- and mTBI-related disability.
Result(s): Twenty-six veterans (46.6+/-8.7 years) with PPTH completed baseline observations and were randomized to either active (n=13) or sham (n=13) treatment groups. A total of 22/25 (88%) participants fully completed either active (10/12) or sham (12/13) interventions (p=.0.59). Within-group analyses reveled significant reductions in moderate/severe headache days in the active (p=0.04) but not sham (p=0.54) groups. This resulted in a trend towards significant reductions in moderate/severe headache days in the active vs. sham groups (p = 0.07). Active participants also demonstrated a reduction in total number of headache days during treatment (p=0.04) where the sham group did not (p=0.70). There is statistically significant reduction in total number of headache days during treatment for active vs. sham participants (p=0.03). No significant differences were maintained during the 4-week post-treatment follow-up (p's>0.05).
Conclusion(s): RS-tDCS treatment feasible with high adherence and effective for veterans with PPTH. Findings suggest that active RS-tDCS via dlPFC reduce headache frequency and improve clinical outcomes. A larger phase II study is warranted to confirm these findings and inform evaluation for clinical use. Research Category and Technology and Methods Clinical Research: 9. Transcranial Direct Current Stimulation (tDCS) Keywords: tDCS, Persistent Post-traumatic headache, Veterans, mTBI
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Transcranial direct current stimulation (tDCS) is an emerging treatment for major depression. We recruited participants with moderate-to-severe major depressive episodes for an observational clinical trial using Soterix Medical's tDCS telehealth platform as a standard of care. The acute intervention consisted of 28 sessions (5 sessions/week, 6 weeks) of the left anodal dorsolateral prefrontal cortex (DLPFC) tDCS (2.0 mA × 30 min) followed by a tapering phase of weekly sessions for 4 weeks (weeks 7-10). The n = 16 completing participants had a significant reduction in depressive symptoms by week 2 of treatment [Montgomery-Åsberg Depression Rating Scale (MADRS), Baseline: 28.00 ± 4.35 vs. Week 2: 17.12 ± 5.32, p < 0.001] with continual improvement across each biweekly timepoint. Acute intervention responder and remission rates were 75 and 63% and 88 and 81% following the taper period (week 10).