特異な筋強直を呈した1症例

A CASE OF RECURRENT MUSCLE CRAMPS

I．はじめに

　筋肉の強直性痙攣をきたす疾患としては，強直性筋ジストロフィー症，Tetanyなどが古くから知られており，最近では，Stiff-man syndrome^1），McArdle病^2）などのほか，Forssman^3），Isaacs^4）5），McQuillenら^7），里吉ら^8），八幡ら^9）により，各種の間歇性筋強直をきたす疾患が，つぎつぎと報告されている。しかし，いずれもその本態ははつきりはつかめていない。最近，われわれもこれらのいずれの報告例とも異なる所見を有する症例を経験したので，文献的考察を加えつつ報告する。

A case of recurrent muscle cramps is reported. A 16-year-old girl has suffered from painful muscle cramps of her fingers, wrists or calves for ten years. The symptom occurred in cold weather or while working. She revealed frontal baldness, cataract, ichthyosis simplex without realizing herself, weak-ness of the sternocleidomastoids and atrophy of the eft triceps muscle (caput laterale) in which low voltage discharge was proved electromyographically. No myotonic phenomena were observed either mechanically or electromyographically. The Trous-seau's sign was negative. The EEG showd a normal record. The EMG during muscle cramp revealed two or three-phasic giant spikes of 4 mV. in amplitude and 20 msec. in duration with a frequency of 25 c/sec., which continued for a few minutes. The evoked EMG showed a normal record. The serum CPK activity was not elevated. The parathyroid function was within normal limits. The serum calcium was 5. 6 mEq/l and the serum inorganic phosphor was 4. 1 mg/dl. The blood lactate was elevated normally by ischemic muscle exercise.

The etiology of this syndrome is not known. This case seems to have similarities with recurrent muscle spasm cases reported by Isaacs (1961) and Satoyoshi (1968) and other related diseases. It seems, however, to he also related to myotonic dystrophy in that it shows frontal baldness and cataract but is different in having no myotonic reactions.