Kovács, Gábor G.

Abstract Reported prevalence estimates of Lewy body pathology (LBP) vary widely, often without considering brain regional distributions or demographic influences. Large, population-representative autopsy cohorts are needed to provide estimates and clarify the distribution and clinical implications of LBP. Neuropathological, genetic, and clinical data were pooled from nine community- or population-based brain autopsy cohorts in the USA (n=6), Brazil, Austria, and Finland (n=7309 total; 59% women; mean age of death 84.2 years). Cognitive status was available for 6166 participants: dementia (38.5%), mild cognitive impairment (14.8%), and cognitively unimpaired (47.0%). Frequency of LBP was examined by anatomical distribution (neocortical, limbic, brainstem, amygdala, olfactory) and stratified by covariates. Prevalence was calculated in meta-analysis, and mixed-effect logistic regression examined associations with sex, cognitive status, Alzheimer’s disease neuropathological change (ADNC), and limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) co-pathology. Overall, 27.3% of participants had LBP: neocortical 8.4%, limbic 6.8%, brainstem 4.8%, amygdala 3.7%, and olfactory 3.6%. Neocortical LBP was associated with dementia (present in 15%; OR=4.06 [95%CI 3.24-5.10]) and with increased odds of ADNC (OR=2.30 [95%CI 1.88–2.81]) and LATE-NC (OR=2.03 [95%CI 1.69-2.44]). Sex differences were not observed in the frequencies of neocortical or limbic LBP. However, amygdala-predominant LBP was more frequent in women (OR=1.53 [95%CI 1.06-2.21]) whereas brainstem-predominant LBP was more common in men (OR=0.64 [95%CI 0.49-0.84]). Additionally, amygdala-predominant LBP was associated with increased odds of comorbid ADNC (OR=12.7 [95%CI 5.30–30.6]) while brainstem-predominant LBP was not associated with greater odds of ADNC co-pathology (OR=0.88 [95%CI 0.67–1.16]). Pooling data from large, international community-based autopsy cohorts allows for more robust estimates of region-specific LBP prevalence and their associations with cognitive status. The observed sex- and co-pathology–specific differences in brainstem and amygdala-predominant LBP highlight potential biological heterogeneity and suggest that distinct disease pathways may underlie these patterns.

Abstract Background Progressive Supranuclear Palsy (PSP) is a rare and severe neurodegenerative tauopathy characterized by diverse clinical phenotypes, including Richardson's syndrome (PSP‐RS), PSP‐parkinsonism (PSP‐P), PSP‐progressive gait freezing (PSP‐PGF), and PSP‐corticobasal syndrome (PSP‐CBS). Significant geographic variation exists in prevalence, clinical presentations, and prognosis. Objectives This global review aims to systematically evaluate the epidemiological variation, clinical phenotypes, diagnostic practices, and management strategies for PSP, focusing on regional disparities and identifying influencing genetic and environmental factors. Methodology A comprehensive literature search following PRISMA guidelines was conducted, analyzing studies reporting PSP epidemiology, phenotypes, diagnostic criteria, risk factors, treatments, and prognoses. Data were categorized into epidemiology, risk factors, clinical presentations, diagnosis, treatment accessibility, and outcomes, considering geographic variation. Results Global PSP prevalence ranges between 5–6.4 per 100,000, influenced by diagnostic criteria and healthcare infrastructure. Clinical manifestations commonly include supranuclear gaze palsy, frequent falls, cognitive impairment, and motor dysfunction. Prognosis significantly varies with subtype; PSP‐RS shows rapid progression and shorter survival (5–7 years), whereas PSP‐P has a milder clinical course (8–12 years). Regional variations highlight differences in genetic predispositions, notably the MAPT H1 haplotype, environmental risk factors such as dietary neurotoxins and industrial pollutants, and accessibility to comprehensive healthcare services. Diagnostic accuracy has improved with the adoption of MDS‐PSP criteria, facilitating recognition of diverse phenotypes. Conclusions Regional disparities in PSP prevalence, phenotypic presentation, and healthcare accessibility underscore the importance of standardized diagnostic criteria, targeted genetic and environmental studies, and equitable healthcare strategies. Enhanced global collaboration is essential for improving PSP diagnosis, management, and patient outcomes worldwide.

ObjectivesTo evaluate the effect of Alzheimer's disease (AD) ‐related biomarker change on clinical features, brain atrophy and functional connectivity of patients with corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP).MethodsData from patients with a clinical diagnosis of CBS, PSP, and AD and healthy controls were obtained from the 4‐R‐Tauopathy Neuroimaging Initiative 1 and 2, the Alzheimer's Disease Neuroimaging Initiative, and a local cohort from the Toronto Western Hospital. Patients with CBS and PSP were divided into AD‐positive (CBS/PSP‐AD) and AD‐negative (CBS/PSP‐noAD) groups based on fluid biomarkers and amyloid PET scans. Cognitive, motor, and depression scores; AD fluid biomarkers (cerebrospinal p‐tau, t‐tau, and amyloid‐beta, and plasma ptau‐217); and neuroimaging data (amyloid PET, MRI and fMRI) were collected. Clinical features, whole‐brain gray matter volume and functional networks connectivity were compared across groups.ResultsData were analyzed from 87 CBS/PSP‐noAD and 23 CBS/PSP‐AD, 18 AD, and 30 healthy controls. CBS/PSP‐noAD showed worse performance in comparison to CBS/PSP‐AD in the PSPRS [mean(SD): 34.8(15.8) vs 23.3(11.6)] and the UPDRS scores [mean(SD): 34.2(17.0) vs 21.8(13.3)]. CBS/PSP‐AD demonstrated atrophy in AD signature areas and brainstem, while CBS/PSP‐noAD patients displayed atrophy in frontal and temporal areas, globus pallidus, and brainstem compared to healthy controls. The default mode network showed greatest disconnection in CBS/PSP‐AD compared with CBS/PSP‐no AD and controls. The thalamic network connectivity was most affected in CBS/PSP‐noAD.InterpretationAD biomarker positivity may modulate the clinical presentation of CBS/PSP, with evidence of distinctive structural and functional brain changes associated with the AD pathology/co‐pathology. ANN NEUROL 2024;96:99–109

Abstract Chronic traumatic encephalopathy (CTE) is a tauopathy associated with repetitive mild head impacts characterized by perivascular hyperphosphorylated tau (p-tau) in neurofibrillary tangles (NFTs) and neurites in the depths of the neocortical sulci. In moderate to advanced CTE, NFTs accumulate in the hippocampus, potentially overlapping neuroanatomically with primary age-related tauopathy (PART), an age-related tauopathy characterized by Alzheimer disease-like tau pathology in the hippocampus devoid of amyloid plaques. We measured p-tau burden using positive-pixel counts on immunohistochemically stained and neuroanatomically segmented hippocampal tissue. Subjects with CTE had a higher total p-tau burden than PART subjects in all sectors (p = 0.005). Within groups, PART had significantly higher total p-tau burden in CA1/subiculum compared to CA3 (p = 0.02) and CA4 (p = 0.01) and total p-tau burden in CA2 trended higher than CA4 (p = 0.06). In CTE, total p-tau burden in CA1/subiculum was significantly higher than in the dentate gyrus; and CA2 also trended higher than dentate gyrus (p = 0.01, p = 0.06). When controlling for p-tau burden across the entire hippocampus, CA3 and CA4 had significantly higher p-tau burden in CTE than PART (p < 0.0001). These data demonstrate differences in hippocampal p-tau burden and regional distribution in CTE compared to PART that might be helpful in differential diagnosis and reveal insights into disease pathogenesis.

ABSTRACT Background Multiple System Atrophy is a rare neurodegenerative disease with alpha‐synuclein aggregation in glial cytoplasmic inclusions and either predominant olivopontocerebellar atrophy or striatonigral degeneration, leading to dysautonomia, parkinsonism, and cerebellar ataxia. One prior genome‐wide association study in mainly clinically diagnosed patients with Multiple System Atrophy failed to identify genetic variants predisposing for the disease. Objective Since the clinical diagnosis of Multiple System Atrophy yields a high rate of misdiagnosis when compared to the neuropathological gold standard, we studied only autopsy‐confirmed cases. Methods We studied common genetic variations in Multiple System Atrophy cases (N = 731) and controls (N = 2898). Results The most strongly disease‐associated markers were rs16859966 on chromosome 3, rs7013955 on chromosome 8, and rs116607983 on chromosome 4 with P ‐values below 5 × 10 −6 , all of which were supported by at least one additional genotyped and several imputed single nucleotide polymorphisms. The genes closest to the chromosome 3 locus are ZIC1 and ZIC4 encoding the zinc finger proteins of cerebellum 1 and 4 (ZIC1 and ZIC4). Interpretation Since mutations of ZIC1 and ZIC4 and paraneoplastic autoantibodies directed against ZIC4 are associated with severe cerebellar dysfunction, we conducted immunohistochemical analyses in brain tissue of the frontal cortex and the cerebellum from 24 Multiple System Atrophy patients. Strong immunohistochemical expression of ZIC4 was detected in a subset of neurons of the dentate nucleus in all healthy controls and in patients with striatonigral degeneration, whereas ZIC4‐immunoreactive neurons were significantly reduced inpatients with olivopontocerebellar atrophy. These findings point to a potential ZIC4‐mediated vulnerability of neurons in Multiple System Atrophy. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society

Abstract Primary age-related tauopathy (PART) is a neurodegenerative entity defined as Alzheimer-type neurofibrillary degeneration primarily affecting the medial temporal lobe with minimal to absent amyloid-β (Aβ) plaque deposition. The extent to which PART can be differentiated pathoanatomically from Alzheimer disease (AD) is unclear. Here, we examined the regional distribution of tau pathology in a large cohort of postmortem brains (n = 914). We found an early vulnerability of the CA2 subregion of the hippocampus to neurofibrillary degeneration in PART, and semiquantitative assessment of neurofibrillary degeneration in CA2 was significantly greater than in CA1 in PART. In contrast, subjects harboring intermediate-to-high AD neuropathologic change (ADNC) displayed relative sparing of CA2 until later stages of their disease course. In addition, the CA2/CA1 ratio of neurofibrillary degeneration in PART was significantly higher than in subjects with intermediate-to-high ADNC burden. Furthermore, the distribution of tau pathology in PART diverges from the Braak NFT staging system and Braak stage does not correlate with cognitive function in PART as it does in individuals with intermediate-to-high ADNC. These findings highlight the need for a better understanding of the contribution of PART to cognitive impairment and how neurofibrillary degeneration interacts with Aβ pathology in AD and PART.

AbstractNeuronal intranuclear inclusion disease (NIID) is a clinically heterogeneous neurodegenerative condition characterized by pathological intranuclear eosinophilic inclusions. A CGG repeat expansion in NOTCH2NLC was recently identified to be associated with NIID in patients of Japanese descent. We screened pathologically confirmed European NIID, cases of neurodegenerative disease with intranuclear inclusions and applied in silico‐based screening using whole‐genome sequencing data from 20 536 participants in the 100 000 Genomes Project. We identified a single European case harbouring the pathogenic repeat expansion with a distinct haplotype structure. Thus, we propose new diagnostic criteria as European NIID represents a distinct disease entity from East Asian cases.