Background: We investigated the gait characteristics of patients with Parkinson's disease (PD), under free-living conditions, using a wearable device, and assessed their relationships with global cognitive function and motor abnormalities.
Methods: The study subjects comprised patients with PD aged < 80 years, with a Mini-Mental State Examination (MMSE) score of ≥20, free of any motor complications. A wearable sensor with a built-in tri-axial accelerometer was waist-mounted on each patient, and continuous, 24-h records were obtained. The mean gait cycle duration and mean gait acceleration amplitude, under free-living conditions, were computed and analyzed to determine their relationship with disease duration, MMSE score, Unified Parkinson's Disease Rating Scale (UPDRS) Part III score, and postural instability and gait difficulty (PIGD) score.
Results: The study included 106 consecutive patients with PD. The mean gait cycle duration was 1.18 ± 0.12 s, which was similar to that of the normal controls. However, the mean gait acceleration amplitude of PD patients (1.83 ± 0.36 m/s2) was significantly lower than that of the control (p < 0.001). In PD patients, the mean gait acceleration amplitude correlated with the MMSE (β = 0.197, p = 0.028), UPDRS Part III (β = - 0.327, p < 0.001), and PIGD (β = - 0.235, p = 0.008) scores.
Conclusions: The gait rhythm of PD patients is preserved at levels similar to those of normal subjects. However, the mean gait acceleration amplitude was significantly reduced in patients with PD. The results indicate that gait acceleration amplitude correlates with the severity of motor disorders and global cognitive function.
Keywords: Free-living gait; Global cognitive function; Parkinson’s disease; Portable device; Wearable sensor.