The use of accelerometry as a tool to measure disturbed nocturnal sleep in Parkinson’s disease

• Published in: NPJ Parkinson's Disease 2018-01, Vol.4 (1), p.1-1, Article 1
• Main Authors: McGregor, Sarah, Churchward, Philip, Soja, Katarzyna, O’Driscoll, Denise, Braybrook, Michelle, Khodakarami, Hamid, Evans, Andrew, Farzanehfar, Parisa, Hamilton, Garun, Horne, Malcolm
• Format: Article
• Language: English
• Subjects: 692/1807/1693; 692/53/2421; 692/617/375/1718; Biomedical and Life Sciences; Biomedicine; Neurology; Neurosciences; Neurovetenskaper; Parkinson's disease; Sleep
• ISSN: 2373-8057; 2373-8057
• DOI: 10.1038/s41531-017-0038-9

Sleep disturbances are common in Parkinson’s disease (PD). We used the Parkinson’s KinetiGraph (PKG), an objective movement recording system for PD to assess night time sleep in 155 people aged over 60 and without PD (controls), 72 people with PD (PwP) and 46 subjects undergoing a Polysomnogram (PSG: 36 with sleep disorder and 10 with normal sleep). The PKG system uses a wrist worn logger to capture acceleration and derive a bradykinesia score (BKS) every 2 min over 6 days. The BKS ranges from 0–160 with higher scores associated with lesser mobility. Previously we showed that BKS > 80 were associated with day time sleep and used this to produce scores for night time sleep: Efficiency (Percent time with BKS > 80), Fragmentation (Average duration of runs of BKS > 80) and Sleep Quality (BKS > 111 as a representation of atonia). There was a fair association with BKS score and sleep level as judged by PSG. Using these PKG scores, it was possible to distinguish between normal and abnormal PSG studies with good Selectivity (86%) and Sensitivity (80%). The PKG’s sleep scores were significantly different in PD and Controls and correlated with a subject’s self-assessment (PDSS 2) of the quality, wakefulness and restlessness. Using both the PDSS 2 and the PKG, it was apparent that sleep disturbances were apparent early in disease in many PD subjects and that subjects with poor night time sleep were more likely to have day time sleepiness. This system shows promise as a quantitative score for assessing sleep in Parkinson’s disease. Health technologies: Measuring sleep disturbances A movement recording system reveals the occurrence of sleep disturbances in the early stages of Parkinson’s disease (PD). Malcolm Horne, a movement disorders expert at the University in Melbourne, and colleagues assessed night time sleep in 72 patients with PD using a wrist-worn device that captures movement patterns. The Parkinson’s KinetiGraph (PKG) system derives scores that are associated with sleep stages and correlate with patients’ self-assessment of sleep quality, wakefulness and restlessness. Significant differences between the PKG sleep scores of PD patients and age-matched healthy controls confirmed that night time sleep disturbances and day time sleepiness worsen as the disease progresses. A bnormal PKG scores were found in patients affected by the disease for only 3 years highlighting the extent to which sleep is disrupted in early-stage PD .