Eye movement especially vertical oculomotor impairment as an aid to assess Parkinson's disease.

Aims: To detect abnormal eye movements in Parkinson's disease and explore its correlation with clinical characteristics and their value for diagnosis. Methods: We recruited forty-nine Parkinson's disease patients, including 35 early Parkinson's disease patients (Hoehn-Yahr: 1 to 2 stage) and 14 advanced Parkinson's disease patients (Hoehn-Yahr: 3 to 5 stage) and 23 healthy controls. Clinical manifestations in Parkinson's disease patients were recorded. Oculomotor performances including fixation, gaze, saccade in horizontal and vertical direction, and smooth pursuit in horizontal and vertical direction were measured by video-oculography. Results: We found that five oculomotor parameters, namely square wave jerk frequency, latency of downward saccade, latency of upward saccade, accuracy of upward saccade, and gain of horizontal smooth pursuit were significantly different in Parkinson's disease patients and controls. When combining all these five parameters, we got the diagnostic sensitivity of 78.3% and specificity of 95.2%. More deficits in upward saccade than in other directions were associated with disease duration and progression of Parkinson's disease. Conclusion: Our primary study suggests that oculomotor examination might serve as an aid in the clinical assessment of Parkinson's disease patients and differentiating between early Parkinson's disease and normal controls. [ABSTRACT FROM AUTHOR]