慢性期前頭葉損傷者を対象とした発動性障害の認知リハビリテーション―実験心理学的課題を用いた反復訓練によるアプローチ

Repetitive practice of psychological tasks in cognitive rehabilitation for loss of psychic self-activation in a patient with frontal lobe lesions

　脳血管障害などを原因として上内側前頭前野が損傷されると，発動性障害と呼ばれる臨床像がしばしば観察される．本研究は，慢性期の前頭葉損傷者を対象に2年間の発動性障害の認知リハビリテーションを実施し，その訓練効果について検討した．標的刺激に対する患者の自発反応を促すために，標的検出課題と視覚探索課題を訓練課題に用いた4つの治療的介入を行った．なお，介入1と介入3ではGo課題，介入2と介入4ではGo/NoGo課題を使用し，反応様式については，介入1，2がボタン押し反応，介入3，4がポインティング反応であった．その結果，発動性障害者に特徴的な反応遅延傾向については訓練効果が明らかでなかったものの，標的刺激に対する自発反応の生起や，刺激の種類に応じた選択的な自発反応の形成が反復訓練によって促進されうることが示唆された．また，遂行機能や空間的注意，日常生活行動の各領域で訓練後に良好な変化が観察された．

　Loss of psychic self-activation or apathy occurs frequently after damage to the superior medial prefrontal cortex. The current study investigated the effectiveness of a 2-year cognitive rehabilitation for the loss of psychic self-activation in a chronic stroke male patient with frontal lobe lesions. The patient received 4 therapeutic interventions consisting of 2 training tasks (target detection task and visual search task) designed to improve his spontaneous response to target stimuli. During the training, Go (Intervention 1, 3) and Go/No-go (Intervention 2, 4) tasks, involving pressing a response button (Intervention 1, 2) or pointing to targets on a screen (Intervention 3, 4) were used. Although there was no noticeable training effect with respect to reaction times, the patient's spontaneous response to the target stimuli (Intervention 1, 3) and his spontaneous selective response according to types of stimuli (Intervention 2) improved with repetitive practice of the training tasks. In addition, he also showed improvement in several tests of executive function and spatial attention, as well as daily life activities, after the cognitive rehabilitation.