Dantroleneが有効であった遅発性ジストニアの1例

A Case of the Antipsychotics-induced Tardive Dystonia Treated Successfully with Dantrolene

　【抄録】　dantroleneが有効であった抗精神病薬による遅発性ジストニアの1例を報告した。症例は25歳の精神分裂病患者で，抗精神病薬の投与を開始して3年7カ月後に頸部に限局した持続性の遅発性ジストニア（retrocollis）を併発した。carbamazepine，抗精神病薬の中止，tiapride，sulpirideは効果なく，clonazepamに若干の効果を認めたものの，dantroleneのみ有効であった。dantroleneの薬理機序より，本症例における遅発性ジストニアの発症には末梢神経神経終末の筋小胞体または中枢神経神経終末のCa^2＋貯蔵部位からのCa^2＋の異常遊離が関与していることが示唆された。

　We reported a case of the antipsychotics-induced tardive dystonia which was treated successfully with dantrolene. The case was that of a 25-year-old schizophrenic patient, who had been prescribed antipsychotics over three years and seven months. There was no family history of dystonia, and laboratory studies showed no abnormalities. He had suffered from posterior neck stiffness and retrocollis for over seven months. Treatment with carbamazepine, and discontinuation of the antipsychotics, tiapride or sulpiride, was without benefit. Clonazepam provided some relief of the posterior neck stiffness. A daily dose of 150 mg dantrolene, p. o. definitely improved both posterior neck stiffness and retrocollis. The efficacy of dantrolene implies that tardive dystonia is probably associated with abnormal calcium release from the sarcoplasmic reticulum in skeletal muscles, or from calcium store in the presynaptic terminals of the central nervous system.