慢性甲状腺机能亢进性肌病(附19例临床、肌电图与病理观察)

Chronic thyrotoxic myopathy-clinical electromyographic and pathological studies on 19 cases

对19例慢性甲状腺机能亢进性肌病,进行了回顾性研究。全部有典型甲亢症状和甲状腺摄^(131)碘率或T_3、T_4值高于正常。先后或同时出现了对称性肢体近端为主肌无力及肌萎缩。6例并发低钾性周期性麻痹。本文对临床特点、诊断、发病机理、EMG和肌活检病理所见,进行了讨论。

19 Cases of chronic thyrotoxic myopathy (CTM) are reported. All of them showed typical clinical features of hyperthyroidism and indices of abnormal thyroid function including ^(131)I absorption, T_3 and T_4 levels. Patients usually develop proximal weakness assieuated with muscle atrophy before, simualtaneously, or shortly after onset of other symptoms of hyperthyroidism. Myalgia Was complained of in 7 cases. Tendon reflexes were either brisk or normal. Hypokalemic periodic paralysis was present in 6 cases.In 10 of 17 cases EMG showed myogenic changes. Muscle biopsies in 8 cases revealed atrophy of muscle fibres and increase in number of nuclei with displacement of nuclei centrally. The ultrastructural abnormalities as revealed by the electron microscope were increase in the number and degeneration of mitochondria, increase in the number of fat droplets, associated with focal myofibrillary degeneration close to Z discs,papillary infolding of the surface membrance.The literature was reviewed, the characteristic features of CTM, it's diagnosis, pathogenesis, EMG and pathological findings are discussed.