漢字の失読と語義失語を伴った筋萎縮性側索硬化症の1例

Amyotrophic Lateral Sclerosis Presented with Alexia of Kanji and Word Meaning Aphasia

　側頭葉の萎縮を伴った筋萎縮性側索硬化症（ALS）の1例を報告した。症例は63歳男性，右手利き。約1年半の経過で漢字の失読，構音障害が進行し入院した。高次脳機能では漢字の失読と呼称の障害が主で，語彙の喪失（意味記憶障害）もみられたため，語義失語と考えた。ALSの症状は球麻痺症状が主で，四肢の筋力低下は目立たなかったが，筋電図では全身に神経原性パターンを認めた。頭部CT，MRI画像では左優位の両側側頭葉の萎縮を認め，SPECTでも側頭葉の血流低下を認めた。本症例は運動ニューロン疾患に側頭葉萎縮を伴い，広い意味でのfrontotemporal lobar degeneration（FTLD）に属すると考えられる。漢字の失読と語義失語を呈した症例の報告はなく，貴重な症例と思われた。

We report a 63-year-old right-handed Japanese man with progressive bulbar dysfunction and alexia of kanji (Japanese morphograms) . He was well until his 62 years of age, when he noted difficulty of reading kanji , which was followed by disturbances in his speech. Reading of kana (Japanese phonograms) was preserved. He also showed naming difficulties with se-mantic memory loss for words, which were character-ized for word meaning aphasia or semantic dementia. He showed dysarthria and mild dysphagia with atro-phy and fasciculations of the tongue.