The subcortical dementia of Huntington's disease.

An effect size analysis incorporating meta-analytic principles was used to review neuropsychological findings in patients with Huntington's disease (HD). Studies dating back to 1980 were gathered and the neuropsychological test results from a total of 760 patients with HD, and 943 healthy controls were synthesized using effect size analyses. The results indicate that patients with HD are most deficient on tests of delayed recall, followed by performance on measures of memory acquisition, cognitive flexibility and abstraction, manual dexterity, attention/concentration, performance skill, and, finally, verbal skill. However, patients with HD display core deficits in fronto-subcortical circuits that give rise to a multitude of cognitive deficits. A rank-order list of specific neuropsychological tasks and test variables in order of sensitivity to HD is also provided to aid in the interpretation of the quantitative results.