Reversible dementia in idiopathic hypoparathyroidism associated with normocalcemia

Dementia in idiopathic hypoparathyroidism is generally ascribed to hypocalcemia and improves following normalization of the serum calcium level.We report a 51-year-old man with severe dementia and hypoparathyroidism, but without serum hypocalcemia and without clinical signs of hypocalcemia. There was rapid and sustained improvement and normalization of symptoms after therapy with 1,25-dihydroxy-cholecalciferol. We conclude that hypocalcemia is not the sole cause of dementia in idiopathic hypoparathyroidism. NEUROLOGY 1996;47: 474-476