The neuropsychology of progressive supranuclear palsy

Abstract

The presence of cognitive and behavioural symptoms in progressive supranuclear palsy (PSP) was recognized even in the first descriptions of the disease. Subsequently, PSP has played an important role in the development of the concept of ‘subcortical dementia’ and in the debates concerning the role of fronto-striatal circuits in cognition and behaviour. The most characteristic neuropsychological features of PSP include general slowness of information processing, deficits in focused and divided attention, impaired initiation, as exemplified by grossly reduced verbal fluency, and a memory impairment affecting active recall to a higher degree than recognition. While all these deficits can be related to impaired ‘frontal-executive functions’, the involvement of other aspects of cognition, particularly language and visuospatial skills, remains controversial. Recent single case studies have highlighted specific linguistic deficits of great theoretical interest. Little is known about the time course of cognitive symptoms, their relation to motor and ocular-motor impairments and their impact on everyday life. Finally, although the described cases may vary significantly in their cognitive performance, as yet, no subgroups with a consistent neuropsychological profile have been identified.