Preserved cognitive skills in dementia of the Alzheimer type.

OBJECTIVE To describe preserved cognitive skills in patients with dementia. DESIGN Case series. SETTING Community clinic. PATIENTS Five patients who met National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for probable Alzheimer's disease and were claimed to retain a cognitive skill. INTERVENTIONS None. MAIN OUTCOME MEASURES Standard neuropsychological tests and individualized measures of patient's skilled behaviors. For patients who remained skilled at games, performance was compared with that of normal controls in direct competition. For the patient-trombonist, raters compared premorbid and postmorbid recordings of his play. RESULTS One patient continued to play the trombone in a Dixieland band, although he could not name well-known numbers that he played. Another continued to solve adult jigsaw puzzles. A third patient retained skill at canasta, the fourth at dominoes. The fifth patient remained a skillful contract bridge player, although he could not name the suits or articulate simple bidding rules. Four patients had impaired performance on standard anterograde and remote memory and naming tests but performed normally on pursuit rotor and letter fluency tests. Mini-Mental State Examination scores for these patients ranged from 10 to 22. One patient refused neuropsychological testing but displayed his skill. CONCLUSIONS Together with previous studies of preserved piano playing or painting skills, our findings indicate that a broad range of complex cognitive abilities may be preserved in patients with dementia of the Alzheimer type who cannot perform simpler actions.