Sleep-wake cycle and 24-h motor activity in early-mid Huntington's disease patients: An actigraphy-based study

Background: Disrupted 24-h sleep-wake and rest-activity cycles are known common features in Huntington's disease (HD) patients; however, critical periods during the 24-h cycle have been less studied. Objective: To analyze the differences between early-mid stage HD patients and healthy controls (HC) in sleep patterns and 24-h motor activity by using actigraphic monitoring. Methods: Twenty HD patients (13 females; mean age ± SD 56.45 ± 16.94) at early-mid stage of the disease and 20 HC were actigraphically monitored for a week. We applied the Functional Linear Modeling (FLM) to analyze motor activity from the actigraphic data. We analyzed parameters regarding both the time spent in bed and out of bed; get-up time (GUT); time in bed (TIB); midpoint of sleep (MS); sleep motor activity (SMA); sleep onset latency (SOL); total sleep time (TST); wake after sleep onset (WASO); sleep efficiency (SE); number and duration of awakenings (AWK); diurnal motor activity (DMA) and diurnal total sleep time (DTST). Results: Ten patients were in Stage I, 6 in Stage II and 4 in Stage III. HD patients presented lower SE and higher TIB, SOL, WASO, AWK and AWK > 5 min in comparison to HC. Moreover, higher motor activity was observed in patients with HD, in particular between 2:15 and 4:00 am, from around 40 min prior to bedtime until 20 min after bedtime, and from around 20 min prior to get-up time until 50 min after get-up time. Conclusions: Actigraphy documented a specific 24-h motor pattern in HD, potentially constituting a disease signature.