Program in Physical Therapy, Washington University in St. Louis, MO, USA.
J Parkinsons Dis. 2011;1(1):109-18. doi: 10.3233/JPD-2011-11019.
Persons with Parkinson disease (PD) experience difficulty turning, leading to freezing of gait and falls. We hypothesized that saccade dysfunction may relate to turning impairments, as turns are normally initiated with a saccade.
Determine whether saccades are impaired during turns in PD and if characteristics of the turn-initiating saccade are predictive of ensuing turn performance.
23 persons with PD off medication and 19 controls performed 90 and 180 degree in-place turns to the right and left. Body segment rotations were measured using 3-D motion capture and oculomotor data were captured using a head-mounted eye tracking system and electrooculography. Total number of saccades and the amplitude, velocity, and timing of the first saccade were determined.
Turn performance (turn duration, number of steps to turn) was impaired in PD (p<0.05). PD performed more saccades, and the velocity and timing of the first saccade was impaired for both turn amplitudes (p<0.05). Amplitude of the first saccade was decreased in PD during 180 degree turns. Turn duration correlated with oculomotor function. Characteristics of the first saccade explained 48% and 58% of the variance in turn duration for 90 and 180 degree turns, respectively.
Turning performance is impaired in PD and may be influenced by saccade dysfunction. An association between saccade function and turning performance may be indicative of the key role of saccades in initiating proper turning kinematics. Future work should focus on improving saccade performance during functional tasks and testing the effects of therapeutic interventions on related outcomes.
帕金森病（PD）患者转身困难，导致步态冻结和跌倒。我们假设扫视功能障碍可能与转身障碍有关，因为转身通常是通过扫视来启动的。
确定 PD 患者在转身时是否存在扫视障碍，以及起始扫视的特征是否可以预测随后的转身表现。
23 名未服用药物的 PD 患者和 19 名对照者分别向右侧和左侧进行 90 和 180 度原地转身。使用三维运动捕捉测量身体节段的旋转，使用头戴式眼动跟踪系统和眼电图记录眼动数据。确定扫视的总数以及第一个扫视的幅度、速度和时间。
PD 患者的转身表现（转身持续时间、转身所需步数）受损（p<0.05）。PD 患者进行了更多的扫视，且两个转角幅度的第一个扫视的速度和时间均受损（p<0.05）。180 度转身时，PD 患者的第一个扫视幅度减小。转身持续时间与眼动功能相关。第一个扫视的特征分别解释了 90 度和 180 度转身持续时间的 48%和 58%的方差。
PD 患者的转身表现受损，可能与扫视功能障碍有关。扫视功能与转身表现之间的关联可能表明扫视在启动适当的转身运动学方面起着关键作用。未来的工作应侧重于在功能性任务中改善扫视性能，并测试治疗干预对相关结果的影响。
