Overnight Monitoring of Turnover Movements in Parkinson’s Disease Using A Wearable Three-Axis Accelerometer

Background: In patients with Parkinson's disease (PD), the impairment of voluntary and involuntary movement during sleep might affect their natural sleep and quality of life; however, there is no reliable method to evaluate turnover movements during sleep. We aimed to clarify whether overnight monitoring of turnover movements in bed using a wearable three-axis accelerometer is a feasible and reliable tool for evaluating the impact of motor complications during sleep in PD. Methods: The number of turnover movements in bed was counted based on the graphic pattern in the X, Y, and Z axis using threshold values in each axis to discriminate turnover movements from other movements mainly associated with respiration or cough. These threshold values were defined by the recordings of various turnover movements in normal volunteers. Overnight monitoring of turnover movements in bed from 9:00 pm to 7:00 am was performed in 7 normal volunteers and 5 patients (mean age, 76.4 ± 4.6 yrs, Hoehn-Yahr stage, 3.6 ± 0.5; duration of disease, 8.8 ± 5.6 yrs). In patients with PD, monitoring was performed before and after adjustment of anti-Parkinson medications. Results: The number of turnover movements was significantly more restricted in PD before drug control than in control subjects (p=0.005). The median number of overnight turnover movements increased from 0 to 5 times after drug control in patients with PD. The number of overnight turnover movements increased significantly in all 5 patients after adjusting their anti-Parkinson medications (p=0.041). Conclusion: Overnight monitoring of turnover movements in bed using a wearable three-axis accelerometer is feasible. Further studies are warranted to evaluate the impact of movement disorders during sleep on patients with PD.