Case Studies1 September 1962Hyperkalemia Familial Periodic Paralysis (Adynamia Episodica Hereditaria)FREDERICK S. ARMSTRONG, M.D.FREDERICK S. ARMSTRONG, M.D.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-57-3-455 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptIn 1956 Gamstorp (1) of the University of Lund, Sweden, reported her observations of a hereditary disorder manifested by periodic paralysis with hyperkalemia rather than hypokalemia as seen in classical familial periodic paralysis. She called this conditionadynamia episodica hereditaria. Undoubtedly many patients who were thought previously to have classical familial periodic paralysis had, in reality,adynamia episodica hereditaria, orhyperkalemic familial periodic paralysis, the term we prefer to use. Several reports prior to Gamstorp's paper contained descriptions of cases with a striking clinical similarity to hyperkalemic familial periodic paralysis (2-10); indeed, 2 reports were about patients from the 2...