Laura J. Balcer

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. Participants were from the Diagnostics, Imaging, and Genetics Network for the Objective Study and Evaluation of Chronic Traumatic Encephalopathy Research Project, which recruited male former college/professional football players with RHI and asymptomatic unexposed (UE) controls with no history of contact sports, military combat, or traumatic brain injury/concussion. Our study focused on plasma/CSF inflammatory biomarkers (interleukin [IL]-6, tumor necrosis factor [TNF]-α, glial fibrillary acidic protein), limbic white matter (WM) microstructure (diffusion tensor imaging: fractional anisotropy [FA], mean diffusivity [MD]), and clinical measures (memory, executive function, NBD). Hierarchical linear regressions assessed change in variance explained (ΔR²) among inflammation, WM, and clinical outcomes in former football players. Post hoc analyses tested whether associations differed by group (football vs UE; group interactions) or were stronger in football players considered at highest risk of CTE. Our sample included 223 men (n = 170 football players: age 57.2 ± 8.1 years, 33% non-Hispanic/Black; n = 53 UE participants: age 59.4 ± 8.6 years, 34% non-Hispanic/Black). In football players, higher inflammation was associated with lower limbic FA (plasma IL-6: ΔR² = 0.03 [0.001-0.09], p = 0.03; CSF IL-6: ΔR² = 0.03 [-0.01 to 0.11], p = 0.03; plasma TNF-α: ΔR² = 0.05 [0.01-0.11], p = 0.003) and higher limbic MD (CSF IL-6: ΔR² = 0.06 [0.007-0.15], p = 0.01). Inflammation was more strongly related to limbic WM microstructure in football players than in UE participants. Worse WM microstructure was associated with worse memory in football players (FA: ΔR² = 0.05 [0.003-0.14], p = 0.007; MD: ΔR² = 0.07, p = 0.003 [0.008-0.16]). Most of the observed associations were stronger in the CTE probable subgroup. There were no direct associations between plasma or CSF markers of inflammation and cognition. 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.

While reductions in optical coherence tomography (OCT) pRNFL and ganglion cell-inner plexiform layer thicknesses have been shown to be associated with brain atrophy in adult-onset MS (AOMS) cohorts, the relationship between OCT and brain MRI measures is less established in pediatric-onset MS (POMS). Our aim was to examine the associations of OCT measures with volumetric MRI in a cohort of patients with POMS to determine whether OCT measures reflect CNS neurodegeneration in this patient population, as is seen in AOMS cohorts. This was a cross-sectional study with retrospective ascertainment of patients with POMS evaluated at a single center with expertise in POMS and neuro-ophthalmology. As part of routine clinical care, patients with POMS are evaluated by a POMS expert and undergo volumetric brain MRI, including whole-brain (WB), subregional, and gray matter (GM) volume analyses. Patients with POMS are routinely referred to neuro-ophthalmology for evaluation that includes high-contrast visual acuity, color vision testing, and OCT. Generalized estimating equation (GEE) models, accounting for within-patient, intereye correlations (both eyes of each patient were included), MS disease duration, and disease-modifying therapy efficacy, were used to determine the relationship between visual pathway structure and function and volumetric MRI measures. Among 61 patients (122 eyes) with POMS, the mean age at the time of the volumetric MRI scan was 19.2 (SD = 3.7, range 10-27) years, with a median disease duration of 2.8 (range 0-14) years. Lower (worse) pRNFL thicknesses (mean 87.4 [17.2] µm) were associated with reduced volume percentiles of WB (p < 0.001, GEE models), total GM (p = 0.025), and thalamus (p = 0.038). pRNFL thinning was also associated with greater lesion (p = 0.006) and black hole (p = 0.028) volumes. Reduced color vision and decreased high-contrast visual acuity were associated with lower hippocampal volumes (p = 0.012 and p = 0.015, respectively). Our results demonstrate that changes in visual pathway structures are associated with reductions in overall brain volume and GM volumes, as well as greater lesion and black hole burden. Collectively, our results emphasize the importance of visual assessment in POMS and suggest that OCT reflects overall CNS neurodegeneration in this cohort.

Burnout is a pervasive occupational hazard for neurologists-undermining their well-being, jeopardizing patient safety and satisfaction, limiting access to care, and inflating health care costs. Well-designed appreciation and recognition practices may help mitigate some of its key drivers. This pilot study evaluates faculty perspectives on appreciation strategies in an academic neurology department. We used the Moffitt Provider Appreciation Assessment (MPAA), which assesses the types of appreciation methods respondents value, regardless of whether those practices are currently implemented in their workplace. A cross-sectional survey was conducted among full-time clinical faculty in the Department of Neurology at NYU Grossman School of Medicine. The survey included demographics, the MPAA, the single-item Mini-Z burnout inventory to assess self-reported burnout levels, and an intent-to-leave question. MPAA responses were analyzed for frequencies, and the association between burnout and intent to leave was examined. Of the 202 faculty members, 77 (38%) participated. The most highly valued appreciation practices were inclusion in decision making (77%), efforts to reduce daily frustrations (75%), and positive feedback from patients and families (71%). Gifts, team celebrations with food, and public affirmations were among the least valued practices. Burnout symptoms were reported by 45% of respondents, and 30% indicated an intent to leave within 2 years. Higher burnout levels were associated with increased intent to leave (p < 0.00001). Because the scores for self-reported burnout and intent to leave reflect current work conditions while MPAA scores capture enduring personal values, MPAA rankings cannot be compared directly with burnout or turnover metrics. Neurology clinical faculty prioritized appreciation methods that directly address clinical work, underscoring the value of implementing tailored recognition practices that may reduce burnout. The methodology used in this pilot study can be adapted for broader application in other settings. After identifying faculty preferences, health care organizations can implement meaningful, transparent, and inclusive appreciation strategies that have the potential to strengthen physician relationships, promote well-being, and support a sustainable workforce.

Disturbances in brain catecholamine activity may be associated with symptoms after exposure to repetitive head impacts (RHIs) or related chronic traumatic encephalopathy (CTE). In this article, we studied CSF catecholamines in former professional and college American football players and examined the relationship with football proxies of RHI exposure, CTE probability, cognitive performance, neuropsychiatric symptoms, and parkinsonism. In this observational cross-sectional study, we examined male former American football players, professional ("PRO") or college ("COL") level, and asymptomatic unexposed male ("UE") individuals from the DIAGNOSE CTE Research Project. Catecholamines-norepinephrine (NE) and its metabolite, 3,4-dihydroxyphenylglycol (DHPG), and dopamine (DA) and its precursor, 3,4-dihydroxyphenylalanine (l-DOPA), and metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC)-were measured in CSF with high-performance liquid chromatography and compared across groups with analysis of covariance. Multivariable linear regression models tested the relationship between CSF catecholamines and proxies of RHI exposure (e.g., total years of playing American football), factor scores for cognition, and neurobehavioral dysregulation (explosivity, emotional dyscontrol, impulsivity, affective lability), as well as depressive/anxiety symptoms, measured with the Beck Depression/Anxiety Inventories. CTE probability and parkinsonism were assessed using the National Institute of Neurological Disorders and Stroke consensus diagnostic criteria for traumatic encephalopathy syndrome (TES), and biomarkers were compared among different diagnostic groups. The cohort consisted of 120 former American football players (85 PRO players, 35 COL players) and 35 UE participants (age 45-75). Former players had significantly lower levels of NE (mean difference = -0.114, 95% CI -0.190 to -0.038), l-DOPA (-0.121, 95% CI -0.109 to -0.027), and DOPAC (-0.116, 95% CI -0.177 to -0.054) than UE participants. For NE and DOPAC, these overall group differences were primarily due to differences between the PRO and UE cohorts. No significant differences were found across TES-CTE probability subgroups or TES-parkinsonism diagnostic groups. Within the COL cohort, tested as post hoc analyses, higher CSF NE and l-DOPA were associated with higher neurobehavioral dysregulation factor scores, BAI total score, and worse executive functioning and processing speed. CSF DHPG and DOPAC were associated with impulsivity only in this subgroup. We observed reduced CSF catecholamine concentrations in former elite American football players, although the relationship with degree of RHI exposure and the clinical impact needs further study.

Exposure to repetitive head impacts (RHI) is linked to the development of chronic traumatic encephalopathy (CTE), which can only be diagnosed at post-mortem. The presence of a cavum septum pellucidum (CSP) is a common finding in post-mortem studies of confirmed CTE and in neuroimaging studies of individuals exposed to RHI. This study examines CSP in living former American football players, investigating its association with RHI exposure, traumatic encephalopathy syndrome (TES) diagnosis, and provisional levels of certainty for CTE pathology. Data from the DIAGNOSE CTE Research Project were used to compare the presence and ratio of CSP in former American football players (n = 175), consisting of former college (n = 58) and former professional players (n = 117), and asymptomatic unexposed controls without RHI exposure (n = 55). We further evaluated potential associations between CSP measures and cumulative head impact index (CHII) measures (frequency, linear acceleration, and rotational force), a TES diagnosis (yes/no), and a provisional level of certainty for CTE pathology (suggestive, possible, and probable). Former American football players exhibited a higher CSP presence and ratio than unexposed asymptomatic controls. Among player subgroups, professional players showed a greater CSP ratio than former college players and unexposed asymptomatic controls. Among all football players, CHII rotational forces correlated with an increased CSP ratio. No significant associations were found between CSP measures and diagnosis of TES or provisional levels of certainty for CTE pathology. This study confirms previous findings, highlighting a greater prevalence of CSP and a greater CSP ratio in former American football players compared with unexposed asymptomatic controls. In addition, former professional players showed a greater CSP ratio than college players. Moreover, the relationship between estimates of CHII rotational forces and CSP measures suggests that cumulative frequency and strength of rotational forces experienced in football are associated with CSP. However, CSP does not directly correlate with TES diagnosis or provisional levels of certainty for CTE, indicating that it may be a consequence of RHI associated with rotational forces. Further research, especially longitudinal studies, is needed for confirmation and to explore changes over time.

We determined inter-modality (in-person vs telemedicine examination) and inter-rater agreement for telemedicine assessments (2 different examiners) using the Telemedicine Buffalo Concussion Physical Examination (Tele-BCPE), a standardized concussion examination designed for remote use. Patients referred for an initial evaluation for concussion were invited to participate. Participants had a brief initial assessment by the treating neurologist. After a patient granted informed consent to participate in the study, the treating neurologist obtained a concussion-related history before leaving the examination room. Using the Tele-BCPE, 2 virtual examinations in no specific sequence were then performed from nearby rooms by the treating neurologist and another neurologist. After the 2 telemedicine examinations, the treating physician returned to the examination room to perform the in-person examination. Intraclass correlation coefficients (ICC) determined inter-modality validity (in-person vs remote examination by the same examiner) and inter-rater reliability (between remote examinations done by 2 examiners) of overall scores of the Tele-BCPE within the comparison datasets. Cohen's kappa, κ, measured levels of agreement of dichotomous ratings (abnormality present vs absent) on individual components of the Tele-BCPE to determine inter-modality and inter-rater agreement. For total scores of the Tele-BCPE, both inter-modality agreement (ICC = 0.95 [95% CI 0.86-0.98, p < 0.001]) and inter-rater agreement (ICC = 0.88 [95% CI 0.71-0.95, p < 0.001]) were reliable (ICC >0.70). There was at least substantial inter-modality agreement (κ ≥ 0.61) for 25 of 29 examination elements. For inter-rater agreement (2 telemedicine examinations), there was at least substantial agreement for 8 of 29 examination elements. Our study demonstrates that the Tele-BCPE yielded consistent clinical results, whether conducted in-person or virtually by the same examiner, or when performed virtually by 2 different examiners. The Tele-BCPE is a valid indicator of neurologic examination findings as determined by an in-person concussion assessment. The Tele-BCPE may also be performed with excellent levels of reliability by neurologists with different training and backgrounds in the virtual setting. These findings suggest that a combination of in-person and telemedicine modalities, or involvement of 2 telemedicine examiners for the same patient, can provide consistent concussion assessments across the continuum of care.

Retinal optical coherence tomography (OCT) provides promising prognostic imaging biomarkers for future disease activity in multiple sclerosis (MS). However, raw OCT-derived measures have multiple dependencies, supporting the need for establishing reference values adjusted for possible confounders. The purpose of this study was to investigate the capacity for age-adjusted z scores of OCT-derived measures to prognosticate future disease activity and disability worsening in people with MS (PwMS). We established age-adjusted OCT reference data using generalized additive models for location, scale, and shape for peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell-inner plexiform layer (GCIP) thicknesses, involving 910 and 423 healthy eyes, respectively. Next, we transformed the retinal layer thickness of PwMS from 3 published studies into age-adjusted z scores (pRNFL-z and GCIP-z) based on the reference data. Finally, we investigated the association of pRNFL-z or GCIP-z as predictors with future confirmed disability worsening (Expanded Disability Status Scale score increase) or disease activity (failing of the no evidence of disease activity [NEDA-3] criteria) as outcomes. Cox proportional hazards models or logistic regression analyses were applied according to the original studies. Optimal cutoffs were identified using the Akaike information criterion as well as location with the log-rank and likelihood-ratio tests. In the first cohort (n = 863), 172 PwMS (24%) had disability worsening over a median observational period of 2.0 (interquartile range [IQR]:1.0–3.0) years. Low pRNFL-z (≤-2.04) were associated with an increased risk of disability worsening (adjusted hazard ratio (aHR) [95% CI] = 2.08 [1.47–2.95], p = 3.82e⁻⁵). In the second cohort (n = 170), logistic regression analyses revealed that lower pRNFL-z showed a higher likelihood for disability accumulation at the two-year follow-up (reciprocal odds ratio [95% CI] = 1.51[1.06–2.15], p = 0.03). In the third cohort (n = 78), 46 PwMS (59%) did not maintain the NEDA-3 status over a median follow-up of 2.0 (IQR: 1.9–2.1) years. PwMS with low GCIP-z (≤−1.03) had a higher risk of showing disease activity (aHR [95% CI] = 2.14 [1.03–4.43], p = 0.04). Compared with raw values with arbitrary cutoffs, applying the z score approach with optimal cutoffs showed better performance in discrimination and calibration (higher Harrell's concordance index and lower integrated Brier score). In conclusion, our work demonstrated reference cohort–based z scores that account for age, a major driver for disease progression in MS, to be a promising approach for creating OCT-derived measures useable across devices and toward individualized prognostication.

Obstructive sleep apnea (SA) is common in older men and a contributor to negative cognitive, psychiatric, and brain health outcomes. Little is known about SA in those who played contact sports and are at increased risk of neurodegenerative disease(s) and other neuropathologies associated with repetitive head impacts (RHI). In this study, we investigated the frequency of diagnosed and witnessed SA and its contribution to clinical symptoms and tau pathology using PET imaging among male former college and former professional American football players. The sample included 120 former National Football League (NFL) players, 60 former college players, and 60 asymptomatic men without exposure to RHI (i.e., controls). Diagnosed SA was self-reported, and all participants completed the Mayo Sleep Questionnaire (MSQ, informant version), the Epworth Sleepiness Scale (ESS), neuropsychological testing, and tau (flortaucipir) PET imaging. Associations between sleep indices (diagnosed SA, MSQ items, and the ESS) and derived neuropsychological factor scores, self-reported depression (Beck Depression Inventory-II [BDI-II]), informant-reported neurobehavioral dysregulation (Behavior Rating Inventory of Executive Function-Adult Version [BRIEF-A] Behavioral Regulation Index [BRI]), and tau PET uptake, were tested. Approximately 36.7% of NFL players had diagnosed SA compared with 30% of the former college football players and 16.7% of the controls. Former NFL players and college football players also had higher ESS scores compared with the controls. Years of football play was not associated with any of the sleep metrics. Among the former NFL players, diagnosed SA was associated with worse Executive Function and Psychomotor Speed factor scores, greater BDI-II scores, and higher flortaucipir PET standard uptake value ratios, independent of age, race, body mass index, and APOE ε4 gene carrier status. Higher ESS scores correlated with higher BDI-II and BRIEF-A BRI scores. Continuous positive airway pressure use mitigated all of the abovementioned associations. Among the former college football players, witnessed apnea and higher ESS scores were associated with higher BRIEF-A BRI and BDI-II scores, respectively. No other associations were observed in this subgroup. Former elite American football players are at risk of SA. Our findings suggest that SA might contribute to cognitive, neuropsychiatric, and tau outcomes in this population. Like all neurodegenerative diseases, this study emphasizes the multifactorial contributions to negative brain health outcomes and the importance of sleep for optimal brain health.