長期間にわたって認知機能障害の改善が続いた慢性髄膜炎後二次性水頭症の1例—展望記憶の改善に着目して

Long-term improvement of cognitive dysfunction focusing on prospective memory deficit caused by secondary hydrocephalus following chronic meningitis: A case study

　慢性髄膜炎後の二次性水頭症により全般的認知機能障害を呈し，約4年間で言語機能，回想記憶，全般的知能に続いて展望記憶の改善に至った症例を報告した．臨床的観察より，注意機能や情報処理能力の持続的な改善が，言語，記憶，遂行機能など高次の機能の改善の支えとなり，最終的に展望記憶の改善に至ったと考えられた．そして，展望記憶には「計画」「監視」「自発性」の部分が共通している遂行機能が主に関与しており，展望記憶の改善には遂行機能・メタ認知・自発性の改善が重要であることが考察された．また，経過中に「他者とのコミュニケーション」が段階的に変化した．認知機能障害の回復には「他者とのコミュニケーション」という視点も重要であることを示唆していると考えられた．

　We report a patient with general cognitive dysfunction resulting from secondary hydrocephalus following chronic meningitis.　Over the period of four years, he showed improvement in various cognitive functions.　It was observed that the amelioration of attention and information-processing led to the improvement of higher brain functions, such as language, retrospective memory, executive function, and finally prospective memory.　Prospective memory shares some features with executive function such as planning, monitoring, and initiation.　It is suggested that the recovery of executive function, meta-cognition, and self-initiation contributed to the amelioration of prospective memory.　The patient's communication behavior also gradually recovered and was thought to have contributed to the improvement of the cognitive functions.