1163 USING WRIST-WORN ACTIGRAPHIC DEVICES TO MEASURE SLEEP IN PEOPLE WITH HUNTINGTON’S DISEASE

Abstract

Introduction:\rSleep disturbances are an early symptom of Huntington’s disease (HD), and may be linked to the cognitive, motor and psychiatric symptoms of HD. Long-term collection of HD ambulatory sleep data can show the impact of sleep disturbances as HD symptoms progress. Actigraphy provides an objective measure of sleep well suited to long-term ambulatory data collection, but is cost prohibitive for large-scale studies. Commercial actigraphy devices may be a good alternative. This study aimed to validate research and commercial actigrapy in people with HD.\rMethods:\rSeven people with the gene for Huntington’s disease (Age=54.1 ± 6.4, 6F) completed an overnight sleep study using polysomnography, research-grade (Actiwatch Spectrum Pro), and consumer-grade (Fitbit One) actigraphy to measure sleep. For each actigraph, sensitivity and specificity compared to polysomnography were calculated. Intraclass correlations (ICCs) and Bland-Altman analyses (BAA) were used to compare the actigraphs to polysomnography on total sleep time (TST), sleep efficiency (SE), sleep latency (SL), and wake after sleep onset (WASO).\rResults:\rThe sensitivity of the research-grade and consumer-grade actigraphs were 97.13% and 98.90% respectively, and specificities were 31.32% and 27.05% respectively. The only significant ICC was the correspondence between the consumer-grade actigraph and polysomnography for TST (r=0.52, p=.03). Using BAA, both actigraphs overestimated TST (Research-grade - Avg.dif=74.3 ± 54.1min; Consumer-grade - Avg.dif=94.3 ± 50.2min) and SE (Research-grade - Avg.dif=14.8 ± 11.0%; Consumer-grade - Avg.dif=17.5 ± 9.8%), and showed good agreement for SL (Research-grade - Avg.dif=-27.9 ± 28.0min; Consumer-grade - Avg.dif=-22.0 ± 24.7 min). The research-grade actigraph showed good agreement with polysomnography on WASO (Avg.dif=-20.0 ± 32.2min), whilst the consumer-grade actigraph underestimated WASO (Avg.dif=-39.0 ± 29.1min).\rConclusion:\rIn people with HD, neither actigraph showed sufficient agreement with polysomnography to be a suitable replacement for ambulatory sleep measurement, particularly considering the very low specificity values. Our research-grade actigraphy performed notably worse than what is typically seen in patient populations. The development of a HD specific actigraphy algorithm would greatly improve the agreement between actigraphy and polysomnography.\r