Parkinson's Disease Tremor Detection in the Wild Using Wearable Accelerometers.

Continuous in-home monitoring of Parkinson's Disease (PD) symptoms might allow improvements in assessment of disease progression and treatment effects. As a first step towards this goal, we evaluate the feasibility of a wrist-worn wearable accelerometer system to detect PD tremor in the wild (uncontrolled scenarios). We evaluate the performance of several feature sets and classification algorithms for robust PD tremor detection in laboratory and wild settings. We report results for both laboratory data with accurate labels and wild data with weak labels. The best performance was obtained using a combination of a pre-processing module to extract information from the tremor spectrum (based on non-negative factorization) and a deep neural network for learning relevant features and detecting tremor segments. We show how the proposed method is able to predict patient self-report measures, and we propose a new metric for monitoring PD tremor (i.e., percentage of tremor over long periods of time), which may be easier to estimate the start and end time points of each tremor event while still providing clinically useful information.

Neuroimaging correlates of lateral postural control in older ambulatory adults.

BACKGROUND: In older adults, impaired postural control contributes to falls, a major source of morbidity. Understanding central mechanisms may help identify individuals at risk for impaired postural control. AIMS: To determine the relationship between gray matter volume (GMV), white matter hyperintensities (WMH), mean diffusivity (MD), and fractional anisotropy (FA) with lateral postural control. METHODS: Neuroimaging and postural control were assessed in 193 community-dwelling older adults (mean age 82, 55.4% female, 44.6% black). GMV, WMH, and diffusion tensor-derived markers of microstructure (MD and FA) were quantified for total brain and regions of interest. Lateral postural control was defined as the root mean square error (RMSE) of lateral sway during a visual feedback test. Associations were assessed with linear regression, adjusted for total brain atrophy and risk factors for impaired postural control. RESULTS: RMSE was higher for women than men (p < 0.001) and inversely correlated with gait speed (r = - 0.20, p = 0.01), modified mini-mental state (r = - 0.27, p < 0.001), digit symbol substitution test (r = - 0.20, p = 0.01) and quadriceps strength (r = - 0.18, p = 0.01). RMSE was inversely associated with GMV of bilateral precuneus (r = - 0.26, p = 0.01) and FA of corpus callosum and selected tracts in the right hemisphere (anterior thalamic radiation, cingulum, inferior longitudinal and fronto-occipital fasciculi), independent of covariates (r = - 0.34 to - 0.18, p ≤ 0.04). DISCUSSION: Lower GMV and microstructural white matter integrity in selected networks can explain worse lateral postural control in older ambulatory adults without neurologic diseases. CONCLUSION: Neuroimaging markers of poor postural control in healthy aging may help identify increased fall risk and design preventative fall strategies.

Association between perioperative stroke and 30-day mortality in carotid endarterectomy: A meta-analysis.

OBJECTIVES: Perioperative stroke is a known complication of carotid endarterectomy (CEA) for patients with symptomatic and asymptomatic carotid stenosis. The Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) has shown that stroke following CEA is associated with nearly a 3-fold increase in the 4-year mortality compared to patients without such an event. However, no studies to date can establish whether the stroke was the cause of the short term mortality. Thus, our objective is to evaluate if perioperative stroke after CEA increases the risk of 30-day mortality. PATIENTS AND METHODS: We performed a meta-analysis of the literature from PubMed and the World Science Database on studies reporting perioperative strokes and 30-day mortality in symptomatic and asymptomatic CEA patients. 3400 articles were retrieved, and abstracts were further screened using the inclusion criteria to obtain a final set of 83 randomized controlled trials and retrospective/prospective studies. RESULTS: A total of 123,507 CEA procedures were included among the 83 studies. The 30-day perioperative stroke rate for all included studies was 2.15%. The 30-day all-cause mortality rate was 0.93%. In patients with perioperative strokes, the 30-day mortality rate was found to be 17.01%. Among patients without perioperative strokes, the 30-day mortality rate was much lower at 0.57%. The summary odds ratio of perioperative stroke and 30-day mortality was 39.86 (95% CI, 29.30-54.23, p < 0.001). CONCLUSION: Patients with perioperative stroke have an almost 40 times increased risk of 30-day stroke-related mortality. This study highlights the importance of developing a preoperative risk assessment and neuroprotective treatment trial for perioperative stroke.