音楽嗜好症（musicophilia）を呈した右側優位側頭葉萎縮の1例

A Case of Musicophilia with Right Predominant Temporal Lobe Atrophy

右側頭葉萎縮と音楽嗜好症を呈する68歳の女性例を経験した。本例では2年前より，それまでなかった流行歌など特定のジャンルの過剰な音楽聴取や歌唱行動が出現した。一方で側頭葉の顕著な萎縮に比して意味記憶障害や相貌失認が目立たず，意欲低下など軽度の行動変化が存在するのみであった。本例の音楽嗜好症は音楽という刺激に特異的に情動の変容と報酬の強化が起こり，音楽関連行動が常同行動化したものと推測された。

Abstract

A 68-year-old woman exhibiting musicophilia with right predominant temporal lobe atrophy happened to visit our clinic. She had no musical background, but beginning two years ago, she acquired a strong preference for especially popular music and sometimes sang at home. She did not exhibit obvious semantic aphasia or facial agnosia, and showed only mild behavioral changes including apathy. Her musicophilia can be explained as an instance of stereotypical behavior. Her right temporal lobe atrophy may have caused changes in her emotional and reward systems, resulting in her music specific behaviors.

(Received June 9, 2015; Accepted August 3, 2015; Published November 1, 2015)