Arimura Kimiyoshi, Arimura Yumiko, Ng Arlene R, Sakoda Shun-Ichi, Higuchi Itsuro
Department of Neurology and Geriatrics, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan.
Muscle Nerve. 2007 Dec;36(6):784-8. doi: 10.1002/mus.20865.
We evaluated whether the paralytic attacks in thyrotoxic periodic paralysis (TPP) are primarily due to the abnormal excitability of the muscle membrane caused by a preexisting latent abnormality or to the effects of thyroid hormone. The prolonged exercise (PE) test was used to evaluate muscle membrane excitability in 21 patients with TPP and 11 patients with thyrotoxicosis without paralytic attacks (Tw/oPP) in the hyperthyroid state. The PE tests were compared between the hyperthyroid and euthyroid states in five of the TPP and three of the Tw/oPP patients. Compared to 20 healthy subjects, a significant increase in compound muscle action potential (CMAP) amplitudes immediately after exercise and a significant time-dependent gradual decline in CMAP amplitudes starting from 20 min after exercise were observed in the TPP patients. A significant decline in CMAP amplitudes was also observed in the Tw/oPP patients but only at 50 min after exercise. All of the TPP and Tw/oPP patients had a tendency to improve in the euthyroid state; the PE tests remained abnormal only in the TPP patients. Paralytic attacks in TPP patients are due primarily to a preexisting latent abnormal excitability of the muscle membrane, possibly genetic in origin.
我们评估了甲状腺毒症性周期性麻痹（TPP）中的麻痹发作主要是由于先前存在的潜在异常导致的肌膜兴奋性异常，还是甲状腺激素的作用。采用长时间运动（PE）试验评估了21例TPP患者和11例甲状腺毒症但无麻痹发作（Tw/oPP）的甲亢患者的肌膜兴奋性。对5例TPP患者和3例Tw/oPP患者在甲亢和甲功正常状态下的PE试验进行了比较。与20名健康受试者相比，TPP患者运动后立即出现复合肌肉动作电位（CMAP）波幅显著增加，且从运动后20分钟开始CMAP波幅出现显著的时间依赖性逐渐下降。Tw/oPP患者在运动后50分钟时CMAP波幅也出现显著下降。所有TPP和Tw/oPP患者在甲功正常状态下均有改善的趋势；PE试验仅在TPP患者中仍异常。TPP患者的麻痹发作主要是由于先前存在的潜在肌膜异常兴奋性，可能起源于遗传。
