[Hypokalemic periodic paralysis. Report of two cases (author's transl)].

The familial periodic hypokalemic paralysis is an infrequent disease characterized by paralytic attacks of sudden appearance affecting the muscles of the trunk and limbs. There is a marked hypokalemia during the paralytic episodes of the disease, and a family history in 80 percent of the cases. The differential diagnosis includes hyperthyroidism with periodic paralysis, congenital paramyotony and adynamia episodica hereditaria. Two typical cases of hypokalemic periodic paralysis are presented, with biological, electrophysiological, clinical, and ultrastructural pictures characteristics of the disease. The clinical manifestations of both patients are discussed, stressing the diagnostic importance of the electrophysiological study during the insulin test, and the interest of the histologic and ultrastructural studies. The spectacular response during the acute episodes to the intravenous perfusion of potassium salts, and the usefulness of the acetazolamide administration to prevent the paralytic episodes are emphasized.