Summary

Evidence suggests that most hyperthyroid patients have a proximal myopathy. The more severe this is the more frequently are distal muscles, and ultimately, bulbar muscles involved. Probably acute thyrotoxic myopathy or encepha-lopathy supervenes on a previous chronic back-ground or occurs concurrently with skeletal muscle involvement. Using careful electromyographic techniques evidence of myopathy may be found in most thyrotoxics; it disappears with adequate treatment of the primary disease. Myasthenia gravis and periodic paralysis are also associated with thyrotoxicosis and their differentiation is discussed. Infiltrative ophthalmo-pathy is not related to the effects of excess thyroid hormone, but is possibly due to EPS working in conjunction with LATS