BODY COMPOSITION IN HYPOKALEMIC FAMILIAL PERIODIC PARALYSIS *

Familial Periodic Paralysis is a rare disease entity probably first described in 1882 by Shakhnowitsch.' The role of potassium in this condition was not appreciated until in 1938 when Aitken et a1.2 related a lowering of serum potassium concentration to the attacks of paralysis. A voluminous literature on periodic paralysis has accumulated since then and recently, it has come to be recognized that there are three conditions in which transitory muscular paralysis may be associated with disturbed electrolyte metabolism. These include classical hypokalemic periodic p a r a l y ~ i s ~ , ~ , ~ as considered in the present communication, a form of hyperkalemic familial periodic paralysis known as adynamia episodica hereditariaaj7 and finally, a form of normokalemic periodic paralysis in which sodium ingestion acts to alleviate attacks.8 Other sporadic forms of periodic paralysis relating to aberrations in potassium metabolism have been described; however, these do not fit the classical description of this disease. Although the literature on periodic paralysis has been extensive, studies of tissue composition and of whole body composition have been