Delirium as the predominant manifestation of hyperparathyroidism: reversal after parathyroidectomy

A 67-year-old woman who had primary hyperparathyroidism presented with delirium rather than dementia as the predominant psychologic manifestation. After surgical removal of a parathyroid adenoma, there was a dramatic improvement in mental status. Psychologic retesting at six weeks after discharge showed her to be well oriented to time, place, and person, with no impairment of cognitive capacity.