Extrapyramidal syndromes in frontotemporal degeneration

Abstract

Descriptions of extrapyramidal (EP) involvement in Pick's disease (renamed recently as FTD) appeared 80 years ago. CBD pathology was confirmed as a common substrate for primary progressive aphasia (PPA). We suggested that CBD and PPA should be included with frontal lobe dementia as Pick complex. PSP was prototype for "subcortical dementia", and aphasia and apraxia, considered unusual for PSP, are now seen as a rule. The overlap of PSP and CBD is considerable. We recently reviewed our cohort with EPS in FTD and identified 22 patients with the movement disorder as a first syndrome and another larger group of 48 patients who developed EPS after an initial onset with a cognitive disorder: aphasic, behavioral or both. All cognitive onset CBD/PSP patients and all but two with motor onset developed aphasia during the course of their illness. General cognitive and behavioral measures are similar for each presentation, but language scores are worse in cognitive onset cases, reflecting the frequency of aphasic presentations. Anomic patients become non-fluent, logopenic, agrammatic and mute. Using the Frontal Behavioral Inventory (FBI), a questionnaire specifically designed for the spectrum of apathy and disinhibition displayed by patients with FTD, we have documented the behavior change in CBD/PSP with motor and cognitive onsets. The significant personality changes consisted of apathy, disinhibition, perseveration and inattention, some of the core symptoms of FTD. In 18 autopsied cases, 15 had tau pathology. The overlap of CBD/PSP with PPA and bvFTD suggests a spectrum of related entities and predicts tau-positive pathology. Cross-sectional studies without significant follow-up may not observe the subsequent development language or behavior deficit, or the evolution from PPA and/or FTD-bv to CBD/PSP.