Conjoint FTLD-FUS of the neuronal intermediate filament inclusion disease type, progressive supranuclear palsy and Alzheimer's pathology presenting as parkinsonism with early falls and late hallucinations, psychosis and dementia

Abstract

Progressive supranuclear palsy (PSP) is a low-prevalence atypical parkinsonism with underlying 4R-tauopathy and a growing number of clinical phenotypes, making its differential diagnosis from other conditions such as Parkinson's disease (PD) and corticobasal degeneration particularly challenging (1,2). Neuronal intermediate filament inclusion disease (NIFID), a sporadic alpha-internexin and fused-in-sarcoma (FUS) proteinopathy, is an even rarer condition with few cases published worldwide. It is most often diagnosed at autopsy, again due to a remarkable clinical heterogeneity ranging from young-onset frontotemporal dementia to PSP-lookalike parkinsonism, among other phenotypes (3-6). This article is protected by copyright. All rights reserved.