Fenocópias de demência frontotemporal: revisão sistemática

Abstract

Background: The phenocopy syndrome frontotemporal dementia (phFTD) refers to patients who mimic behavioral variant of frontotemporal dementia (bvFTD), but lack frontotemporal atrophy on neuroimaging and do not progress to frank dementia during the follow-up. It is important to recognize phFTD for clinical and research purposes. Objective: The aim of this study was to perform a systematic review of available literature about phFTD, considering its clinical, cognitive, imaging, genetic and pathological aspects. Methods: We searched for the following terms on two electronic databases (PubMed and Scopus): frontotemporal dementia and slowly progressive, frontotemporal dementia and phenocopy, frontotemporal dementia and non-progressive, frontotemporal dementia and benign progression and frontotemporal dementia and benign. We did not include review articles; no chronological limits were adopted. Results: A total of 235 studies were retrieved on the initial search. A total of 31 studies composed the final selection. Patients with phFTD are generally male and have no major cognitive deficits, with globally preserved executive functions and episodic memory. Some cases of slowly progressive FTD have been associated to C9orf72 genetic expansion. There are only four studies reporting pathological data on phFTD, with two cases with no neurodegenerative findings and two with frontotemporal lobar degeneration. Conclusion: The neurobiological underpinnings of phFTD remain unknown. It is controversial whether phFTD belong to the FTD spectrum. More studies with biomarkers and pathological data may help to disentangle the question.