Are We Missing Early-onset Frontotemporal Dementia as Late-onset Primary Psychiatric Disorder? A Case Series

Abstract

Abstract Frontotemporal dementia (FTD) presents with a wide variability in clinical progressive syndromes, genetic etiologies, and underlying pathologies. Early diagnosis of combined features of behavioral and language variants of FTD poses a clinical challenge due to its complex heterogeneous clinical presentations, phenotypical overlap, and frequent normal neuroimaging during the initial phase. This masquerading nature has often led to unintended “misdiagnoses,” as typical dementia features evolve late. The enigmatic resemblance of early-onset (<65 years of age) FTD with a range of late-onset (>45 years of age) primary psychiatric disorders emphasizes the need for high index of clinical suspicion, thorough family history for neurocognitive disorders, and regular follow-up of such individuals. We describe the clinical profile and management of four cases of combined variant FTD (cvFTD) that clinically mimicked late-onset psychiatric disorders such as catatonia, depressive disorder, psychosis, and personality changes. Parkinsonian-like features and mid-brain atrophy in FTD may indicate phenotypical overlap and shared neuropathology with progressive supranuclear palsy.