Josephs, Keith A.

Accurate antemortem diagnosis of parkinsonism is primarily based on clinical evaluation with limited biomarkers. We evaluated the diagnostic utility of quantitative rapid eye movement (REM) sleep without atonia analysis in the submentalis and anterior tibialis muscles in parkinsonian patients (53 synucleinopathy, 24 tauopathy). Receiver operating characteristic curves determined REM sleep without atonia cutoffs distinguishing synucleinopathies from tauopathies. Elevated submentalis muscle activity was highly sensitive (70–77%) and specific (95–100%) in distinguishing synucleinopathy from tauopathy. In contrast, anterior tibialis synucleinopathy discrimination was poor. Our results suggest that elevated submentalis REM sleep without atonia appears to be a potentially useful biomarker for presumed synucleinopathy etiologies in parkinsonism. ANN NEUROL 2019;86:969–974

Background: Few studies have investigated the incidence of PSP and CBS in the population. Objective: To examine the incidence of and trends in progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) in a population-based cohort of residents of Olmsted County, MN. Methods: We used the 1991-2005 population-based, Olmsted County Parkinsonism-cohort study, defined via the Rochester Epidemiology Project. A movement-disorder specialist reviewed medical records, to confirm PSP and CBS diagnoses. Results: We identified 21 patients with these diagnoses 1991-2005 : 18 (85.7%), PSP; 3 (14.3%), CBS. The median diagnosis age was 78 (range: 66-88). 13/21 (62.0%) were male. MRI was performed pre-diagnosis in 11 patients (8 PSP and 3 CBD); 10 showed atrophy consistent with clinical diagnoses. We observed concordance between clinical and pathological diagnoses in two PSP patients who underwent autopsy. Combined incidence for PSP and CBS in Olmsted County was 3.1 per 100,000 person-years (2.6 per 100,000 person-years, PSP; 0.4 per 100,000 person-years, CBS). Incidence was higher in men (4.5, 95% CI, 2.0-7.0) than women (1.8, 95% CI, 0.5-2.9). A combined, significant trend of increasing incidence was observed between 1991 and 2005 (B=0.69, 95% CI 0.42, 0.96, p<0.001). Median time from symptom onset to death among both groups was 6 years (range PSP, 1-10 years; range CBS, 3-8 years). Conclusions: The combined incidence for PSP and CBS was 3.1 per 100,000 person-years, higher in men than women. We observed a significant increase in both PSP and CBS, likely due to advancing imaging technology and improved diagnostic ability among physicians.

The specific effect of TDP-43 pathology on grey matter volume in individuals without frontotemporal lobar degeneration is unclear. Bejanin et al. reveal a major and independent contribution of TDP-43 to neurodegeneration and shed light on the regional distribution of TDP-43-related atrophy in older adults.

Abstract Background Progressive supranuclear palsy (PSP) is a neurodegenerative disorder characterized by neuronal loss in the extrapyramidal system with pathologic accumulation of tau in neurons and glia. The most common clinical presentation of PSP, referred to as Richardson syndrome, is that of atypical parkinsonism with vertical gaze palsy, axial rigidity, and frequent falls. Although cognitive deficits in PSP are often ascribed to subcortical dysfunction, a subset of patients has dementia with behavioral features similar to the behavioral variant of frontotemporal dementia. In this study we aimed to identify the clinical and pathological characteristics of PSP presenting with frontotemporal dementia. Methods In this study, we compared clinical and pathologic characteristics of 31 patients with PSP with Richardson syndrome with 15 patients with PSP with frontotemporal dementia. For pathological analysis, we used semiquantitative methods to assess neuronal and glial lesions with tau immunohistochemistry, as well image analysis of tau burden using digital microscopic methods. Results We found greater frontal and temporal neocortical neuronal tau pathology in PSP with frontotemporal dementia compared with PSP with Richardson syndrome. White matter tau pathology was also greater in PSP with frontotemporal dementia than PSP with Richardson syndrome. Genetic and demographic factors were not associated with atypical distribution of tau pathology in PSP with frontotemporal dementia. Conclusions The results confirm the subset of cognitive‐predominant PSP mimicking frontotemporal dementia in PSP. PSP with frontotemporal dementia has distinct clinical features that differ from PSP with Richardson syndrome, as well as differences in distribution and density of tau pathology. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Abstract Introduction The corticobasal syndrome (CBS) is associated with several neuropathologic disorders, including corticobasal degeneration and Alzheimer's disease (AD). Method In this report, we studied 43 AD patients with CBS (AD‐CBS) and compared them with 42 AD patients with typical amnestic syndrome (AD‐AS), as well as 15 cases of corticobasal degeneration and CBS pathology. Results Unlike AD‐AS, AD‐CBS had prominent motor problems, including limb apraxia (90%), myoclonus (81%), and gait disorders (70%). Alien limb phenomenon was reported in 26% and cortical sensory loss in 14%. Language problems were also more frequent in AD‐CBS, and memory impairment was less frequent. AD‐CBS had more tau pathology in perirolandic cortices but less in superior temporal cortex than AD‐AS. In addition, AD‐CBS had greater neuronal loss in the substantia nigra. Discussion AD‐CBS is a clinicopathological subtype of AD with an atypical distribution of Alzheimer‐type tau pathology. Greater neuronal loss in the substantia nigra may contribute to Parkinsonism which is not a feature of typical AD.