BIT線分二等分試験と抹消試験でみられる上下方向の無視の特徴

Characteristics of neglect observed in line bisection and cancellation tasks of the Behavioral Inattention Test

要旨：無視空間の特徴を知る目的で，USN患者202名のBIT線分二等分試験と線分抹消試験，文字抹消試験，星印抹消試験を上・中・下段で比較した．結果は線分二等分試験のみが特徴的な左下の無視空間を呈した．他の抹消試験は上・中・下段の左側無視に差がなく，上下方向の空間認知が可能なことを明らかにした．損傷部位の比較では前頭葉損傷群が線分二等分試験の上・下段の差でUSNを捉えられることが新たに認められた．このような特徴から空間認知要因が強い課題は上下左右の標的を近接させ，視覚探索要因が強い課題は上下方向へ誘導することが無視空間への気づきを促すと考えられ，これらを考慮すると効率的な作業療法につながると思われた．

　This study investigated 202 patients with USN (unilateral spatial neglect) due to cerebral infarction and hemorrhage. The line bisection, line cancellation, letter cancellation, and star cancellation tasks of the Behavioral Inattention Test were examined by placing the task sheets involved into upper, middle, and lower rows. It was found that only the line bisection task was associated with a neglect of the lower left side. Other cancellation tasks with visual search content evoked no difference in the neglect of the left sides of the upper, middle, and lower rows in patients, and showed that spatial recognition in a vertical direction was possible. It was noted that the frontal lobe lesion group could overcome USN by identifying the differences between the upper and lower rows on the line bisection task. Based on these findings, bringing a target closer to a task that has intense visual search features, such as the line bisection task, and guiding the target in a vertical direction in the search for content on a cancellation task may promote an awareness of the neglected space.