Reversibility of cognitive impairment in medical inpatients.

To determine outcomes of patients admitted to the hospital with global cognitive impairment and to identify factors that might predict improvement, we screened all medical ward admissions over a one-month period with Folstein's Mini-Mental State Examination. Of 115 patients, 23 (20%) scored less than 24, indicating that they were cognitively impaired. Nineteen patients survived to discharge and were followed up for three months; three additional patients died in this period. Nine (47%) of the 19 patients significantly improved their Mini-Mental State scores. Five (26%) of the 19 improved to normal. They scored better on the initial Mini-Mental State Examination and lower (less dementia) on Blessed's Dementia Rating Scale. Age, severity and stability of medical illness, presence of neurologic abnormalities, clinical course, extensiveness of medical evaluation, and psychiatric criteria for delirium did not predict improvement.