ビデオ画像注視課題における半側空間無視の異常眼球運動パターンの検討

Abnormal eye movement patterns on a 2-point alternate fixation task and a routes finding task in unilateral spatial neglect

要旨：本研究の目的は，半側空間無視(USN)患者におけるビデオ画像注視中の異常眼球運動パターンの特徴を調べることである．対象者(USN群10名，右片麻痺群10名，健常群10名)の2点交互注視課題と道順課題での眼球運動をアイカメラで測定した(TKK2920)．USN群は2点交互注視課題では注視軌跡が左上方に逸脱し，2点間距離が短いと右点注視時間は左点注視時間より長くなった．道順課題の視線角度は左折時では他群に比較し右方にあり，左空間での探索が不十分なことが示された．道順課題で観察された視覚探索の右偏位の有無は，2点交互注視課題で観察された他の眼球運動異常パターンよりもADLへの影響が大きいことが予測された．

　The purpose of this study was to investigate characteristics of eye-fixation patterns and abnormal eye-movement patterns of unilateral spatial neglect patients during the visual tasks presented on video display. Subjects were 30 individuals including 10 stroke patients with USN, 10 stroke patients with right-hemiplegia, and 10 healthy controls. Tracking of eye movement on tasks, which were a 2-point alternate fixation task and a routes finding task, was recorded by the eye camera, and vision angle and fixation period were analyzed by computer software (Takei, TKK2920). In the 2-point alternate fixation task, USN eye-fixation patterns deviated from horizontal midline to upper left. The right fixation period was longer than the left when distance between 2 target points was short. In the routes finding task, the vision angle pattern of USN showed insufficiency of leftward exploring. This right deviation, more so than other abnormal patterns, might have a strong effect on the activities of daily living.