EXECUTIVE AND MNEMONIC FUNCTIONS IN EARLY HUNTINGTONS-DISEASE

Eighteen patients with early Huntington's disease were compared with a ge- and IQ-matched control volunteers on tests of executive and mnemon ic function taken from the Cambridge Neuropsychological Test Automated Battery. Tests of pattern and spatial recognition memory, spatial spa n, spatial working memory, spatial planning and visual discrimination learning/attentional set shifting were employed. These tests have prev iously been found to be sensitive to the later stages of Huntington's disease. Patients with early Huntington's disease were found to have a wide range of cognitive impairments encompassing both visuospatial me mory and executive functions, a pattern distinct from those seen in ot her basal ganglia disorders. In contrast to patients with more advance d Huntington's disease, early Huntington's disease patients were not i mpaired at simple reversal learning, but were impaired at performing a n extradimensional shift (EDS). The results will be discussed in relat ion to the hypothesized neuropathological staging of Huntington's dise ase and to the anatomical connectivity of the striatum.