Boeve, Bradley F.

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

Abstract Study Objectives Values for normative REM sleep without atonia (RSWA) remain unclear. Older age and male sex are associated with greater RSWA, and isolated elevated RSWA has been reported. We aimed to describe normative RSWA and characterize isolated RSWA frequency in adults without REM sleep behavior disorder (RBD). Methods We visually quantified phasic, “any,” and tonic RSWA in the submentalis (SM) and anterior tibialis (AT) muscles, and the automated Ferri REM Atonia Index during polysomnography in adults without RBD aged 21–88. We calculated RSWA percentiles across age and sex deciles and compared RSWA in older (≥ 65) versus younger (<65) men and women. Isolated RSWA (exceeding diagnostic RBD cutoffs, or >95th percentile) frequency was also determined. Results Overall, 95th percentile RSWA percentages were SM phasic, any, tonic = 8.6%, 9.1%, 0.99%; AT phasic and “any” = 17.0%; combined SM/AT phasic, “any” = 22.3%, 25.5%; and RAI = 0.85. Most phasic RSWA burst durations were ≤1.0 s (85th percentiles: SM = 1.07, AT = 0.86 seconds). Older men had significantly higher AT RSWA than older women and younger patients (all p < 0.04). Twenty-nine (25%, 18 men) had RSWA exceeding the cohort 95th percentile, while 17 (14%, 12 men) fulfilled diagnostic cutoffs for phasic or automated RBD RSWA thresholds. Conclusions RSWA levels are highest in older men, mirroring the demographic characteristics of RBD, suggesting that older men frequently have altered REM sleep atonia control. These data establish normative adult RSWA values and thresholds for determination of isolated RSWA elevation, potentially aiding RBD diagnosis and discussions concerning incidental RSWA in clinical sleep medicine practice.

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.

AbstractIntroductionBehavior/Comportment/Personality (BEHAV) and Language (LANG) domains were added to the Clinical Dementia Rating (CDR®) for improving evaluation of patients with frontotemporal lobar degeneration (FTLD) (CDR® plus NACC FTLD).MethodsWe analyzed the CDR® plus NACC FTLD among participants from the baseline visit of the Advancing Research and Treatment for Frontotemporal Lobar Degeneration/Longitudinal Evaluation of Familial Frontotemporal Dementia Subjects Consortium.ResultsThe CDR® plus NACC FTLD was able to detect early symptoms in the mildly impaired participants who were rated as CDR® sum of boxes (CDR®‐SB) = 0. The CDR®‐SB was not sensitive, particularly in participants with mild nonfluent/agrammatic primary progressive aphasia. Participants with familial and sporadic behavioral variant FTD exhibited similar CDR® plus NACC FTLD profiles except that language impairment was more frequent in participants with mild sporadic behavioral variant FTD. Adding the BEHAV and/or LANG domains to the CDR®‐SB significantly enhanced discriminatory power in differentiating among the FTLD spectrum disorders.DiscussionThe BEHAV and LANG domains enable the CDR® plus NACC FTLD to capture early symptomatology of FTLD.

See Gordon and Tijms (doi:10.1093/brain/awz278) for a scientific commentary on this article. Jack et al. examine relationships between the bivariate distribution of β-amyloid and tau on PET and established neurocognitive clinical syndromes. Amyloidosis appears to be required for high levels of 3R/4R tau deposition. Whereas abnormal amyloid PET is compatible with normal cognition, highly abnormal tau PET is not.