Cognitive functioning in neurologically symptomatic and asymptomatic forms of Wilson's disease.

We sought to determine the pattern of cognitive deficits in patients with Wilson's disease (WD) with different type and degree of neurological involvement, and to interpret the findings in relation to the underlying pathology. A total of 67 WD patients were examined with a neuropsychological test battery assessing different aspects of cognitive processing. The patients were subdivided into three groups: neurologically asymptomatic, neurological with pure basal ganglia lesions, and neurological with more extensive pathology. The results were compared with 50 matched healthy controls. Patients with a neurological form of WD showed a mild but definitive impairment in all cognitive functions. In contrast, the neurologically asymptomatic patients showed no deficits when compared with normal controls. Multifocal pathology was associated with more severe cognitive deficits than selective basal ganglia lesions but did not contribute significantly to memory impairment. A range of cognitive functions, including frontal-executive ability, aspects of memory and visuospatial processing, are affected in the neurologically symptomatic WD patients. In contrast, no subliminal deficits were observed in the asymptomatic patients. The lesions of the basal ganglia seem to be of central importance in explaining the symptomatology.