Record Detail

In people with Parkinson’s disease (PD), anticipatory postural adjustments may be prolonged, reduced in amplitude, or absent,
contributing to impaired gait initiation. In addition to motor symptoms, disturbance of the circadian rhythm (CR) is one of
the common non-motor symptoms of PD. The purpose of this study was to investigate whether time of day modulates the
magnitude of gait initiation impairment, and furthermore, if there is any relationship between CR dysfunction and impaired
postural control in PD. Seven consecutive 24-h periods of wrist actigraphy (as a measure of CR), and then gait initiation
studies (at two different times, 9:00 a.m. and 2:30 p.m., of the same day) were conducted in two cohorts of ten subjects each:
people with PD, and age-matched control subjects. We found that in the PD group, the amplitude of medial/lateral center
of pressure (CoP) excursions were significantly reduced in the afternoon as compared with the morning session across all
trials (p < 0.05). Actigraphy results showed that CR amplitude was significantly decreased (p< 0.05) in the PD group, which
suggests that the PD group suffered from CR disruption. More importantly, changes in medial/lateral CoP displacement were
correlated with abnormal CR amplitude in the PD group. These findings provide novel evidence that diurnal fluctuations in
treatment-resistant motor symptoms of PD, such as postural and gait initiation deficits, are associated with CR dysfunction.
This study supports the idea that therapeutic correction of circadian misalignment should be considered in combination with
pharmaceutical and rehabilitation treatments of motor symptoms in PD.