Non-Alzheimer's Disease Dementias: Anatomic, Clinical, and Molecular Correlates

Objective: To review the clinical and molecular features of non-Alzheimer's disease (non-AD) dementias, focusing on disorders associated with tau pathology (that is, frontotemporal lobar degeneration [FTLD], corticobasal ganglionic degeneration [CBD], and progressive supranuclear palsy [PSP]) or on disorders with synuclein pathology (that is, dementia with Lewy bodies [DLB] and multisystem atrophy [MSA]). We also discuss the pharmacologic treatment of these disorders. Methods: We report a selective review of the literature on FTLD, CBD, PSP, DLB, and MSA. Results: The non-AD dementias can present with a wide variety of cognitive and behavioural symptoms. Through common clinical features and shared molecular etiologies, neurodegenerative disorders previously thought to be distinct are now classified into tauopathies and synucleinopathies. Conclusions: The unique cognitive and behavioural manifestations of the non-AD dementias can be mistaken for psychiatric disorders. Improved detection of tauopathies and synucleinopathies and their differentiation from AD is possible.