多彩な所見と下垂体性甲状腺機能低下症を伴った慢性進行性外眼筋麻痺の1例

A Case of Chronic Progressive External Ophthalmoplegia with Pituitary Hypothyroidism

　慢性進行性外眼筋麻痺で，下垂体性甲状腺機能低下症など多彩な所見を有した1例を報告した。症例は34歳，女性。14歳の時，難聴を訴え，諸医を受診したが次第に進行し，全聾となった。既に16歳で眼瞼下垂が始まっていたのが，今にして昔のアルバムで確認できるが，33歳でようやく他人から眼瞼下垂を，また34歳で異常眼球運動を指摘され，さらに言語障害も自覚し始めてきたため受診。筋生検でragged-redfiberとcytochrome c oxidaseの部分欠損とミトコンドリアDNAの欠失を認め，慢性の進行性外眼筋麻痺に感音性難聴と，異常なCT, MRI，脳波および脳幹誘発電位のほか，TRH負荷試験でTSH分泌が低下し，脳下垂体性の甲状腺機能低下症を呈した。これらのことから，Kearns-Sayre症候群は古典的3徴候がそろわなくても多臓器障害を有する可能性を示唆した。

We report a case of chronic progressive external ophthalmoplegia with pituitary hypothyroidism. This patient had complained of hearing-loss at the age of fourteen and loss of body weight at fifteen. She was examined by otorhinolaryngologists at large hospitals yearly over a period of 5-6 years, but hearing-loss remained unknown. As her ophthalmo-plegia progressed (as is evident from family photo-graphs from the age of sixteen onward) , with hind-sight it should have been recognized.

When examined on October 11, 1991, she com-plained of ptosis, speech disturbance and dysphagia at the age of thirty-four. Neurological examination revealed limitation of ocular movement, bilateral ophthalmoplegia, facial muscle atrophy, and weak gag reflex. She showed muscle atrophy in her neck including both sternocleidomastoid, major and minor rhomboid, girdle and distal parts of upper and lower extremities. Muscle biopsy of her biceps demonstrated ragged-red fibers, cytochrome c oxidase (CCO) deficien fibers and deletion of mito-chondrial DNA. A plain CT scan revealed bilateral periventricular lucency, and a brain MR image showed a normal sized pituitary gland but diffuse high-signal intensities in the both periventricular white matter with proton density weighted and T2-weighted axial MR image. And also her electroen-cephalogram showed diffuse 7 Hz slow waves in all areas and increased slow waves by hyperventila-tion, and all waves from I to V of the auditory brain stem response disappeared. The effect of TRH on serum TSH secretion was not evident in this patient. This case was ascertained to be chronic progressive external ophthalmoplegia with pitui-tary hypothyroid function.