Ruff R L, Weissmann J
Cleveland Veterans Administration Medical Center, Ohio.
Neurol Clin. 1988 Aug;6(3):575-92.
The atrophy produced by endocrine disorders is primarily due to alterations in protein and carbohydrate metabolism. Type II muscle fibers are more severely affected than are Type I fibers. Steroid myopathy and the myopathy associated with excess ACTH have a typical pattern of proximal weakness affecting the legs more than the arms. Steroid myopathy is usually not apparent until other signs of glucocorticoid excess are present. Treatments of steroid myopathy are as follows: Lower the dose of steroid, use a nonfluorinated glucocorticoid, and exercise or physical therapy. Adrenal insufficiency produces generalized weakness, muscle cramping, and fatigue in 50 per cent of patients. Some patients also develop hyperkalemic paralysis. The treatment is hormone replacement. Thyrotoxicosis produces myopathy caused by net protein catabolism, accelerated basal metabolic rate and impaired carbohydrate metabolism. Shortening of contraction time may result from accelerated myosin ATPase activity and enhanced calcium uptake by the sarcoplasmic reticulum. Depolarization of the muscle fiber and impaired Na-K activity in muscle may predispose to thyrotoxic periodic paralysis. Neuromuscular presynaptic impairment may account for the worsening of myasthenia gravis by thyrotoxicosis. In hypothyroidism, impaired energy metabolism may limit force generation. Slow contraction and relaxation reflect reduction in myosin ATPase activity and impaired calcium uptake by the sarcoplasmic reticulum. Treatment for thyroid-associated muscle disorders is restoration of a euthyroid state. Muscle weakness associated with hypopituitarism is due to loss of thyroid and adrenal cortical hormones. Children require growth hormone for muscle development. T3 and growth hormone synergize to maintain normal protein synthesis. Primary and secondary hyperparathyroidism and osteomalacia are often associated with proximal weakness and fatigability. The myopathy improves with restoration of normal PTH levels and vitamin D replacement. Hypoparathyroidism and pseudohypothyroidism are associated with tetany. Tetany is worsened by alkalosis and is treated by calcium and magnesium replacement.
内分泌紊乱所致的萎缩主要归因于蛋白质和碳水化合物代谢的改变。II型肌纤维比I型肌纤维受影响更严重。类固醇肌病以及与促肾上腺皮质激素过多相关的肌病具有典型的近端肌无力模式，对腿部的影响大于手臂。类固醇肌病通常在出现糖皮质激素过多的其他体征后才会显现。类固醇肌病的治疗方法如下：降低类固醇剂量，使用非氟化糖皮质激素，以及进行锻炼或物理治疗。肾上腺功能不全在50%的患者中会导致全身无力、肌肉痉挛和疲劳。一些患者还会发生高钾性麻痹。治疗方法是激素替代。甲状腺毒症会导致肌病，其原因是净蛋白分解代谢、基础代谢率加快以及碳水化合物代谢受损。肌球蛋白ATP酶活性加快和肌浆网钙摄取增加可能导致收缩时间缩短。肌纤维去极化以及肌肉中钠钾活性受损可能易引发甲状腺毒症性周期性麻痹。神经肌肉突触前损害可能是甲状腺毒症使重症肌无力恶化的原因。在甲状腺功能减退症中，能量代谢受损可能会限制力量的产生。收缩和舒张缓慢反映了肌球蛋白ATP酶活性降低以及肌浆网钙摄取受损。甲状腺相关肌肉疾病的治疗是恢复甲状腺功能正常状态。与垂体功能减退相关的肌肉无力是由于甲状腺和肾上腺皮质激素缺乏所致。儿童肌肉发育需要生长激素。T3和生长激素协同作用以维持正常的蛋白质合成。原发性和继发性甲状旁腺功能亢进以及骨软化症常伴有近端肌无力和易疲劳。随着甲状旁腺激素水平恢复正常和补充维生素D，肌病会有所改善。甲状旁腺功能减退症和假性甲状旁腺功能减退症与手足搐搦有关。碱中毒会使手足搐搦加重，治疗方法是补充钙和镁。
