純粋失読1例に対するモバイル端末の活用効果—文字認識・音声読み上げアプリケーションの臨床応用

Clinical application of a mobile device with Optical Character Recognition/Reader Applications for a case of pure alexia

　純粋失読を呈した1症例に対し，モバイル端末の文字認識・音声読み上げアプリケーション(以下，アプリ)を用いて読字の代償手段としての有効性を検証した．対象は70歳代の右利き男性で，約20年前に左脳内出血を発症し，後遺症として純粋失読，記憶障害，右同名半盲を認め，長文の読字が困難であった．アプリを使用した条件と非使用条件で，A4用紙に印刷された長文(平均353文字)の読解課題を8題実施し，所要時間と正答率を比較した．この結果，アプリ使用条件では非使用条件に比べて，読解成績は維持しながらも，所要時間は約3分の2程度に有意に短縮した．この結果から，モバイル端末の文字認識・音声読み上げアプリは本例のような読字障害に対して，有効な支援ツールとなることが示唆された．

　In this study, we investigated the effectiveness of rehabilitating a patient with pure alexia using character recognition and reading applications installed in a mobile device. We examined a right-handed man in his 70s, who had experienced left cerebral hemorrhage 20 years ago. He exhibited selective and severe reading impairments, moderate amnesia, and right homonymous hemianopsia. We recorded and compared his reading performance under two conditions. A reading device was used in the first condition, but not in the second. The response times under the two conditions were significantly different. Although the correct answer rates were equivalent, the response time obtained in the first condition was shorter, approximately two-thirds of that obtained in the second condition. These results reveal that character recognition and reading applications in a mobile device are effective for helping patients with pure alexia.