Links between frontotemporal lobar degeneration, corticobasal degeneration, progressive supranuclear palsy, and amyotrophic lateral sclerosis.

Frontotemporal lobar degeneration, corticobasal degeneration (CBD), progressive supranuclear palsy, and amyotrophic lateral sclerosis have been considered distinct clinicopathologic entities with few issues in common other than neurodegeneration being central to all. The aim of this paper is to highlight the clinical, topographic, pathologic, proteomic, and genetic similarities among these disorders and the syndromes through which each disorder is exhibited. The critical roles of tau and TAR DNA-binding protein 43 (TDP-43) dysfunction in the disorders and syndromes are emphasized. Although confusion certainly remains, and the ability to predict the underlying proteinopathy in the various neurodegenerative syndromes is far from perfect, there is optimism that insights gained over the next few years will enhance our ability to accurately identify the amyloidopathies, tauopathies, and TDP-43opathies early in the disease course, potentially improving the ability to impact these diseases once targeted therapies have been developed.