分類困難な家族性筋萎縮症の1例

A CASE OF UNCLASSIFIED FAMILIAR MUSCULAR ATROPHY

I．緒言

　筋萎縮を主徴とする疾患は，従来神経原性，筋原性の2群に大別され^6）12），発病年令・遺伝歴・筋萎縮の分布様式・経過等を基準にして診断。分類がなされていたが，近年筋生検・筋電図検査・血清中諸酵素活性値の測定・内分泌学的検査等によりさらに細かい分類が可能かつ容易になつた。また筋萎縮を随伴症状とする疾患も各科領域でみいだされている。いつぽう日常臨床上非定型例に遭遇し診断に迷うことも依然多いが，上記の2群のいずれに属せしめるべきかで困惑することは非常に稀と思われる。

　われわれは筋病様の筋萎縮・深部反射亢進・完全尿閉を主症状とする22歳男子例を経験したが両親は血族結婚で姉に類似の症状を認める。各種検索を試みたが神経原性・筋原性のいずれに属するかも決めかねるような症例なのでここに報告し御教示を得たく思う。

A 22-year-man came to the Clinic in Septem-ber, with the chief complaints of urinary reten-tion for one year and weight loss for three years.

On admission he aparently had symmetric muscular atrophy of trunk and extremities (especially proximal group). Deep reflexes were markedly hyperactive, but no other py-ramidal symptoms were discovered at any time. Abdominal reflexes were absent bilaterally. No fibrillation was found. There were neither pains, cutaneous eruptions, nor any other neu-rological abnormalities. Results of general ex-amination were not remarkable. Electromyo-gram of light biceps brachialis muscle revealed low amplitude NMU voltage at voluntary con-traction but non the other. Biopsy suggested dystrophic changes in the deltoid muscle. Uri-nary creatine was 246mg per day, creatinine 500mg per day. Serum aldolase was 10 U. The results of X ray examination were as follows: skull, negative; cervical thoracic and lumbar spinal columns, negative; stomach, chronic gastritis; myelogram, negative ; urethro-cys-togram revealed spasm of external urinary sphincter. In spite of therapeutic trials, no im-provement could be attained. His sister also had similar symptomes except for urinary ret-ention.

We discussed differential diagnosis of this case, but question as to what of muscular atrophy takes place from these findings cannot esasily answered.