Citations

ObjectiveTo use a cluster analysis of [18F]AV‐1451 tau‐PET data to determine how subjects with Alzheimer's disease (AD) vary in the relative involvement of the entorhinal cortex and neocortex, and determine whether relative involvement of these two regions can help explain variability in age and clinical phenotype in AD.MethodsWe calculated [18F]AV‐1451 uptake in entorhinal cortex and neocortex in 62 amyloid‐positive AD patients (39 typical and 23 atypical presentation). tau‐PET (positron emission tomography) values were normalized to the cerebellum to create standard uptake value ratios (SUVRs). tau‐PET SUVRs were log‐transformed and clustered blinded to clinical information into three groups using K‐median cluster analysis. Demographics, clinical phenotype, cognitive performance, and apolipoprotein e4 frequency were compared across clusters.ResultsThe cluster analysis identified a cluster with low entorhinal and cortical uptake (ELo/CLo), one with low entorhinal but high cortical uptake (ELo/CHi), and one with high cortical and entorhinal uptake (EHi/CHi). Clinical phenotype differed across clusters, with typical AD most commonly observed in the ELo/CLo and EHi/CHi clusters, and atypical AD most commonly observed in the ELo/CHi cluster. The ELo/CLo cluster had an older age at PET and onset than the other clusters. Apolipoprotein e4 frequency was lower in the ELo/CHi cluster. The EHi/CHi cluster had the worst memory impairment, whereas the ELo/CHi cluster had the worst impairment in nonmemory domains.InterpretationThis study demonstrates considerable variability in [18F]AV‐1451 tau‐PET uptake in AD, but shows that a straightforward clustering based on entorhinal and cortical uptake maps well onto age and clinical presentation in AD. Ann Neurol 2018 Ann Neurol 2018;83:248–257

Abstract Background Cognitive impairment is one of the core features of progressive supranuclear palsy. This study aimed to clarify the profile of cognitive impairment and its underlying pathology in progressive supranuclear palsy. Methods We retrospectively reviewed medical records to evaluate the pattern and severity of cognitive impairment in 121 autopsy‐confirmed progressive supranuclear palsy patients. A subset of 37 patients underwent neuropsychological evaluation as part of their clinical workup. The burden of progressive supranuclear palsy‐related tau pathology (neurofibrillary tangles/pretangles, coiled bodies, tufted astrocytes, and threads) was semiquantitatively scored in 20 vulnerable brain regions. Concurrent pathologies potentially associated with cognitive impairment, such as Alzheimer's‐type pathology, were also assessed. To evaluate possible genetic risk factors for cognitive impairment, genetic analysis for APOE and MAPT was performed. Results Ninety patients (74%) had documented cognitive impairment based on neurologic evaluation. In a subgroup with neuropsychological testing (n = 37), executive functioning was the most severely impaired cognitive domain. A global cognitive impairment index (Spearman's rho, −0.49; P = 0.005) and executive functioning were negatively correlated with total tau burden (Spearman's rho, −0.51; P = 0.003), but not correlated with the Alzheimer's‐type pathology. APOE ɛ4 carriers had more severe amyloid pathology, but total tau burden and a global cognitive impairment index did not differ from APOE ɛ4 noncarriers. Conclusion Cognitive impairment in progressive supranuclear palsy, most notably executive dysfunction, is associated with severity of progressive supranuclear palsy‐related tau pathology. © 2017 International Parkinson and Movement Disorder Society

ABSTRACTObjective: The purpose of this study was to examine the discrepancies between the clinical diagnosis of parkinsonism and neuropathological findings in a population‐based cohort with parkinsonian disorders.Background: The specific clinical diagnosis of parkinsonism is challenging, and definite confirmation requires neuropathological evaluation. Currently, autopsies are seldom performed, and most brain autopsies represent atypical or diagnostically unresolved cases.Methods: We used a defined population‐based incidence cohort with clinical parkinsonism (n = 669) from the Rochester Epidemiology Project in Olmsted County, Minnesota, 1991‐2010. We reviewed reports of all patients who underwent neuropathologic examination at autopsy (n = 60; 9%) and applied consensus pathologic guidelines for neurodegenerative disease diagnosis.Results: Among the 60 patients examined pathologically, the median time from the last recorded clinical diagnosis to death was 7 years (range from 2 to 17 years). Clinical–pathological concordance was found in 52 cases (86.7%), whereas 8 (13.3%) had a clinical‐pathological discrepancy. Four patients with a clinical diagnosis of idiopathic Parkinson's disease had no pathological evidence of Lewy bodies or α‐synucleinopathy; of these, pathological diagnoses were Alzheimer's disease (2 cases), progressive supranuclear palsy (1 case), and vascular parkinsonism (1 case). Two patients with clinical diagnoses of "dementia with Lewy bodies" and one patient with an "unspecified parkinsonism" had a pathological diagnosis of Alzheimer's disease without concomitant α‐synuclein lesions. One patient with clinically diagnosed "progressive supranuclear palsy" had indeterminate pathological findings without α‐synuclein or Aβ‐ or tau‐immunoreactive lesions at autopsy.Conclusions: Overall, the clinical diagnoses of parkinsonian subtypes had good concordance with pathological confirmation (86.7%). However, clinical–pathological discrepancies were documented in 13.3%. © 2017 International Parkinson and Movement Disorder Society