Adler, Charles H.

ABSTRACT Objective To determine the test performance of cutaneous phosphorylated alpha‐synuclein (P‐SYN) in dementia with Lewy bodies (DLB), individuals with reduced Montreal Cognitive Assessment (MoCA) and healthy controls. Methods This is the first subgroup analysis of the Synuclein‐One study, a prospective, blinded study evaluating P‐SYN detection from skin biopsies in 218 subjects with a referral diagnosis of control ( N = 151) and DLB ( N = 67). All subjects completed detailed examinations, questionnaires, and had skin biopsies for detection of P‐SYN. DLB patients were included if meeting the 4th DLB consensus probable criteria. Control subjects, aged 40–99, had no history, examination findings, or symptoms suggestive of a synucleinopathy or neurodegenerative disease. An expert review panel, blinded to pathological data, determined the final diagnosis. Controls with reduced MoCA (MoCA < 26, N = 26) at screening were analyzed separately. Results After expert panel review, only 50/67 patients met consensus criteria for DLB, 26/151 controls had a reduced MoCA, and 120/151 controls had a normal MoCA. The proportions of subjects with cutaneous P‐SYN detected by skin biopsy were 96.0% (48 of 50) of the DLB group, 31% (8 of 26) of the controls with reduced MoCA, and 3.3% (4 of 120) of the controls with normal MoCA. Interpretation In this prospective, blinded, cross‐sectional study, a high proportion of subjects meeting clinical consensus criteria for DLB had P‐SYN detected in skin biopsies. Almost 1/3 of subjects with reduced MoCA testing also had P‐SYN detected. These results support a role for skin biopsy detection of P‐SYN in patients with DLB. Trial Registration NCT04700722

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with exposure to repetitive head impacts (RHI). In CTE, hyperphosphorylated tau (p-tau) aggregates are found in neurons at the depth of cortical sulci close to the gray matter/white matter (GM/WM) boundary. To date, CTE can only be diagnosed postmortem by neuropathological examination. Traumatic encephalopathy syndrome (TES) is the clinical syndrome purported to be associated with CTE pathology. The aim of this study is to investigate microstructural properties at the GM/WM boundary in individuals with a history of exposure to RHI and clinical features of CTE (i.e., TES). Diffusion magnetic resonance imaging (dMRI), TES diagnoses, and cerebrospinal fluid (CSF) biomarkers were acquired from 165 male former American football players (age: 57.29 ± 8.23 years) from the DIAGNOSE CTE Research Project, a multicenter, observational cohort study. Fractional anisotropy (FA) was measured at the GM/WM boundary of the whole brain. In addition, a widely used method (tract-based spatial statistics [TBSS]) was applied to measure FA of central WM. We used analyses of covariance to test associations between FA and TES. Furthermore, we used linear regressions to test associations between FA and nine CSF biomarkers (i.e., p-tau-181, -217, -231, total tau, amyloid β [Aβ] 1–40 , Aβ 1–42 , glial fibrillary acidic protein [GFAP], neurofilament light [NfL], and soluble triggering receptor expressed on myeloid cells-2 [sTREM2]). We report an association between higher FA at the GM/WM boundary and higher levels of certainty for CTE pathology ( F (1, 147) = 5.781, 95% confidence interval (CI) = 0.0003–0.003, p = 0.035) as well as neurobehavioral dysregulation ( F (1, 148) = 7.559, 95% CI = 0.001–0.009, p = 0.020), and functional dependence/dementia ( F (1, 148) = 5.046, 95% CI = 0.0004–0.006, p = 0.039). In addition, we report an association between higher FA at the GM/WM boundary and higher CSF p-tau-181 (β = 0.272, 95% CI = 0.078–0.466, p = 0.029) and p-tau-217 (β = 0.295, 95% CI = 0.102–0.488, p = 0.027). FA of the central WM was not associated with TES diagnoses. Taken together, these findings suggest that dMRI at the GM/WM boundary could be used to investigate microstructural alterations suggestive of tau pathology-associated neurodegeneration in individuals with TES, the clinical presentation of CTE. Future studies are needed to validate this approach and to identify clinically useful cutoff values for dMRI metrics.

Abstract Repetitive head impacts are common in contact and collision sports and are linked to structural brain changes and an elevated risk of neurodegenerative diseases such as Chronic Traumatic Encephalopathy. Identifying early in vivo structural markers remains challenging. Although diagnosis currently requires post-mortem confirmation, clinical symptoms, including cognitive impairment and behavioural changes, are reflected in the diagnosis of Traumatic Encephalopathy Syndrome. These symptoms align with dysfunction in key brain regions—amygdala, hippocampus and thalamus—which support memory, emotion and behaviour and commonly show tau pathology in Chronic Traumatic Encephalopathy. This study uses shape analysis to examine structural differences in these regions between former American football players and unexposed asymptomatic controls and evaluates the influence of age, head impact exposure and clinical diagnosis on brain structure. We analyzed brain morphology in former American football players (n = 163) and unexposed, asymptomatic controls (n = 53). Structural segmentation was performed with FreeSurfer 7.1, and the shape analysis pipeline was used to generate subregional reconstructions. Vertex-level morphometry, based on the logarithm of the Jacobian determinant and radial distance, quantified local surface area dilation and thickness. Group differences were examined with covariate-adjusted linear regression models contrasting football players and controls, as well as participants with and without a Traumatic Encephalopathy Syndrome diagnosis. Partial correlations examined the influence of age, age of first football exposure and cumulative head impact index metrics, including frequency, linear acceleration and rotational force. Models were adjusted accordingly for age, body mass index, education, race, imaging site, apolipoprotein ϵ4 status and total intracranial volume. Former football players exhibited bilateral surface area contractions in the hippocampus and amygdala, along with reduced amygdala thickness, compared to controls. Older age was associated with widespread surface contractions and thinning across all regions, except for preserved thickness in the left hippocampus. An earlier age of first exposure to football correlated with surface contractions in the thalamus and left hippocampus. Greater cumulative linear acceleration was linked to bilateral hippocampal surface contractions and reduced thickness in the left thalamus, while greater rotational force exposure was associated with hippocampal thinning. No significant structural differences were found between players with and without a diagnosis of Traumatic Encephalopathy Syndrome. These findings extend volume-based research by revealing localized alterations in surface area dilation and thickness and emphasize the roles of age and repetitive head impact exposure in long-term brain changes.

Abstract Repetitive head impacts are associated with structural brain changes and an increased risk for chronic traumatic encephalopathy, a progressive neurodegenerative disease that can only be diagnosed after death. Chronic traumatic encephalopathy is defined by the abnormal accumulation of phosphorylated tau protein, particularly at the depths of the superior frontal sulci, suggesting that sulcal morphology may serve as a relevant structural biomarker. Contact sport athletes, such as former football players, are at elevated risk due to their prolonged exposure to repetitive head impacts. Cortical atrophy linked to underlying tau accumulation may result in shallower and wider sulci, potentially making sulcal morphology an imaging marker for identifying individuals at risk for this disease. This study investigated sulcal morphological differences in former football players and examined associations with age, football-related exposure, clinical diagnosis of traumatic encephalopathy syndrome, levels of certainty for chronic traumatic encephalopathy pathology, neuropsychological performance, and positron emission tomography imaging using flortaucipir. We analysed structural magnetic resonance imaging data from 169 male former football players (mean age 57.2 (8.2) years, range 45–74) and 54 age-matched, unexposed asymptomatic male controls (mean age 59.4 (8.5) years, range 45–74). Sulcal depth and width were quantified using the CalcSulc, focusing on two regions in each hemisphere commonly affected by chronic traumatic encephalopathy pathology: the superior frontal and occipitotemporal sulci. Generalized least squares models were used to assess group differences and interactions with age and football exposure variables, including age of first exposure, total years played, and cumulative head impact exposure. An analysis of covariance evaluated relationships between sulcal morphology, clinical measures, and flortaucipir uptake, adjusting for age, race, body mass index, education, imaging site, apolipoprotein E4 status, and total intracranial volume. Former football players demonstrated significantly shallower sulcal depth in the left superior frontal sulcus compared to unexposed controls. Earlier age of first exposure and longer football careers were associated with greater widening of the left occipitotemporal sulcus. Higher cumulative head impact exposure was linked to reduced sulcal depth in the left superior frontal region. However, sulcal morphology was not associated with clinical diagnosis, levels of certainty, neuropsychological test performance, or flortaucipir imaging. These findings suggest that sulcal morphology may reflect cumulative exposure to repetitive head impacts, particularly in brain regions vulnerable to chronic traumatic encephalopathy pathology. Future ante- and post-mortem validation studies are needed to determine whether sulcal morphology can serve as a reliable in vivo biomarker of risk.

Abstract Bioinformatics methods can be used to quantify mitochondrial DNA copy number from whole genome sequencing (WGS) data. We evaluated mitochondrial DNA copy number from human brain-derived WGS data using the fastMitoCalc tool. 341 Parkinson’s Disease cerebellum samples were compared with 74 age-matched controls from the North American Brain Expression Consortium. Parkinson’s Disease cerebellum had significantly higher mitochondrial DNA copy number compared with controls (P = 4.15e–7), and this effect was reproducible in four of five brain banks when analysis was restricted to each resource that contributed Parkinson’s Disease samples to this genetic dataset. Follow-on analyses of 128 Parkinson’s Disease cerebellum samples and 33 controls that had paired neuropathology data and clinical scores demonstrated a significant increase in mitochondrial DNA copy number with Unified Staging System for Lewy Body disorders stages and Unified Parkinson’s Disease Rating Scale (off meds) motor scores. Analysis of Lewy Body scores from ten brain regions showed cerebellum mitochondrial DNA copy number increased upon pathological infestation of α-synuclein aggregates in the brainstem and limbic system but did not increase after late-stage neocortical involvement. This genetics dataset supports previous observations of cerebellum activation in Parkinson’s Disease and suggests mitochondrial DNA copy number may increase to support this regional activation as a compensatory mechanism to pathology or motor symptoms.

Objectives/Hypothesis: Botulinum neurotoxin type-A (BoNT-A) injection into the true vocal cords is an effective treatment for restoring vocal functionality in adductor spasmodic dysphonia (AdSD). The Glasgow Benefit Inventory was developed to measure quality of life change following any otolaryngologic intervention and was recently revised to a 5-factor subdomain (GBI-5F) questionnaire to improve clinical utility. The study aim was to utilize the GBI-5F to measure patient-reported quality of life change in AdSD patients following BoNT-A injection. Methods: The GBI-5F questionnaire was administered to patients diagnosed with AdSD who received a BoNT-A vocal cord injection between December 2022 and May 2023. All patients had received multiple prior injections. GBI-5F subdomains and demographics were analyzed to identify areas for patient-reported improvement. Results: Sixty-six patients completed the GBI-5F. There were 52 (78.7%) females and average age was 69.4 years. The median total benefit score was +40.0 (interquartile range [IQR], 20.0). Median subdomain scores were +83.3 (IQR, 50.0) for quality of life, +50.0 (IQR, 50.0) for self-confidence, +33.3 (IQR, 33.3) for social involvement, +16.7 (IQR, 50.0) for support, and 0.0 (IQR, 16.7) for general health. Differences in the individual subdomain scores were statistically significant ( P < .0001). No significant differences were found in the total GBI-5F score or any subdomain according to sex or presence of vocal tremor (all P > .05). A moderately positive correlation was noted between median total score and percent functional improvement (r = 0.46, P < .001). Conclusion: Botulinum injection therapy for AdSD provides overall benefit to patients as measured by the GBI-5F, with particular improvement observed for perceived quality of life, self-confidence, and social involvement. Sex, presence/absence of vocal tremor, and age do not appear to modify benefit, though degree of functional improvement is positively correlated with total score.