Impaired ability to turn in bed in parkinson's disease as a potential rare cause of positional asphyxia: a...

Nocturnal hypokinesia commonly affects Parkinson's disease (PD) patients, manifesting primarily as an impaired ability to turn in bed and sleeping in specific positions, such as prone that potentially poses the risk of positional asphyxia.

To objectively evaluate, using axial inertial sensors (the NIGHT-Recorder), the ability of PD patients and controls to turn in bed from prone to supine position and to correlate these parameters with disease severity scores.

Turning in bed from prone to supine position was assessed in 16 PD patients with a moderate disease stage and 16 age-matched controls using the NIGHT-Recorder. Successful turning was defined as a full 180 ° turn from prone to supine position as evidenced by the NIGHT-Recorder. Objective parameters included duration, velocity, and acceleration of turn. The ability to turn in bed was determined by torque per kilogram body weight (T/kg).

Two out of 16 PD patients (12.5%) could not initiate their turns. PD patients turned with a significant longer duration (p = 0.04), slower velocity (p = 0.04), and acceleration (p = 0.04) compared to controls. Although PD patients had lower T/kg than controls, the difference was not significant. Several significant correlations were demonstrated between turning parameters and clinical rating scales (Duration vs. UPDRS axial: r=0.51, p = 0.04; T/kg vs. PDSS-2: r=0.53, p = 0.03; T/kg vs. NHQ: r=0.52, p = 0.03).

Our study provides objective evidence of impaired turning in bed from prone to supine position in PD patients with nocturnal hypokinesia. Appropriate measures should be taken to improve nocturnal mobility in those at risk.