視覚認知障害が移動能力に及ぼす影響とその支援についての新知見—2症例からの検討

New findings on the effect of visual cognitive dysfunctions on mobility and support for these impairments: A review of two cases

要旨：視覚認知障害が移動能力に及ぼす影響，ならびに支援・対応について，既存の報告へ追加の知見を加えることを目的に症例検討を行った．1例目は，視覚性注意障害により，ランドマークを見落とし道に迷う様子や，道路横断に際した判断の遅れを認めた．2例目は，変形視，距離判断障害，オプティックフローの知覚障害といった視知覚の異常から，移動時の距離感や階段・風景の見え方に異常を認めた．2症例とも，従来の視覚情報（地図・目印）を用いた代償手段では，移動能力の改善を認めなかった．脳損傷後の移動能力を精査・支援する際には，多彩な視覚認知機能障害を考慮する必要性が示唆された．

　This case report aims to add additional knowledge to existing reports on the effect of visual cognitive dysfunction on mobility, and support for mobility through case reports and literature review. In the first case, the patient experienced visual inattention, which led the patient to miss landmarks, get lost, and experience delayed judgment when crossing roads. The other patient had metamorphopsia and abnormalities in distance judgment and optic flow, which resulted in abnormalities in distance perception during movement and climbing stairs and in landscape vision. Neither patient showed improvement in mobility with compensatory strategies using conventional visual information, such as maps and landmarks. These findings underscore the importance of considering a range of visual cognitive dysfunctions when assessing and supporting mobility after brain injury.