Pattern of intellectual impairment in Huntington's chorea.

Cognitive function was evaluated in 11 patients with Huntington's chorea, using eight subtests of the WAIS, and their performance was compared with that previously reported for a normal aged population. The pattern of impairment was similar in the two groups. Tests of immediate memory were given to nine of these patients, and to 10 healthy but aged subjects. In both groups, there was a significant correlation between the performance of individuals in these tests and their IQ, suggesting that the choreic patients had no selective impairment of immediate memory. The clinical and psychological records of the 11 patients revealed no evidence of focal deficits, and the majority of patients were fully orientated and retained insight to their condition. These observations are discussed in relation to the pattern of intellectual impairment seen in other presenile dementias.