Progressive supranuclear palsy with dementia: cortical pathology.

Patients with progressive supranuclear palsy (PSP) often develop dementia, and cortical pathology has been documented in PSP. However, there are no reports correlating dementia in PSP with cortical pathology. We hypothesized that cases of PSP presenting with cognitive impairment would have more severe cortical tau pathology than those without. We compared 7 cases of PSP presenting with cognitive deficits (group 1) with 4 cases of PSP that did not (group 2). The subcortical tau pathology was almost identical in both groups. The cortical tau pathology was strikingly different in group 1, in which it was on average moderate, compared with group 2, in which it was minimal. The accumulation of cortical neuronoglial tau in PSP cases with dementia suggests that neurofibrillary pathology is central to the cause of dementia in PSP.