Number impairments following hypokalemia: a case study.

A case study is reported of a 55 year old female (B.B.) who complained of significant difficulty manipulating and remembering numbers. Twenty-four years prior to the present complaint, B.B. had been hospitalized for idiopathic hypokalemia and secondary hyperaldosteronism. The present study examined the nature and extent of B.B.'s cognitive impairments. On standardized and experimental tests of intelligence and general cognitive ability, she scored quite well. However, she demonstrated significant impairments in digit span, number processing and calculation, memory for biographical details involving numbers and general number knowledge. The implications of such a constellation of impairments are discussed from both cognitive and neurological perspectives.