Thyrotoxic periodic paralysis: a peculiar case with unusual dystonic behavior and variable relations of paralysis to serum potassium levels.

This report describes a male patient, aged 49, with tyrotoxic periodic paralysis. The patient had had episodes of main d'accoucheur for eight years. Since thyrotoxicosis had affected the patient last year, he had had attacks of flaccid paralysis of the limbs associated with main d'accoucheur. While the spontaneous attack was normokalemic and responded favorably to potassium, attacks similar to the spontaneous one were provoked not only by glucose infusion, carbohydrate feeding, and NaCl infusion, but also by oral KCl administration. Transition from hypokalemic to hyperkalemic type of paralysis occurred during potassium treatment of a sodium-induced attack, and that from hyperkalemic to hypokalemic type of paralysis occurred after glucose infusion given during a potassium-induced attack. Intra-arterial epinephrine injection caused prompt paralysis of the perfused hand. A main d'accoucheur was induced in one hand by cooling it in chilled water. The spontaneous attacks of flaccid paralysis disappeared after the patient returned to the euthyroid state, but reappeared when he was treated with high doses of desiccated thyroid. Even when the patient was relieved from thyrotoxicosis, he still experienced stiffness in his hands. The administration of glucose, insulin, and KCl also provoked attacks of paralysis with main d'accoucheur or main d'accoucheur. The disease could be of the normokalemic variety of periodic paralysis with fluctations in the potassium levels depending on the provocative tests employed. It seems that the unusual dystonic behavior of this patient is due not to myotonia, but to muscle spasm resulting from metabolic abnormalities. It could also be suggested that excess thyroid hormones have adverse effects on the development and syndrome of periodic paralysis by abetting a latent hereditary abnormality.