抄録
The present study compared the effect of eye movements on postural control in 13 Parkinson’s disease (PD) patients (Hoehn-Yahr stage 2-3) and 13 age-matched healthy adults. Participants viewed, from a distance of 1 m, a computer display of an oscillating object that continuously changed shape and reported the number of times the shape changed over each 60 s trial. Four oscillation rates (0, 0.5, 0.8, and 1.2Hz) were presented. Postural sway data (mean position, standard deviation, and range of the excursions in the anterior-posterior and medio-lateral directions) were obtained using a wireless motion tracking system via sensors attached to each participant’s head, neck, and cervical spine. The effect of eye movement frequency on postural sway was minimal in the healthy adults, consistent with the view that postural control and suprapostural task (eye movement control) are functionally integrated to facilitate the performance of suprapostural control tasks. By contrast, PD patients’ showed greater and more variable postural sway, particularly in the anterior-posterior direction. It appears that PD patients’ impaired postural control systems are no longer integrated functionally with their eye movement control. This result suggests an additional factor to consider in PD patients who are susceptible to falls due to postural instability.
