Tauopathies: Classification, Clinical Features, and Genetics

Neurodegenerative diseases are characterized by the deposition of biochemically abnormal proteins. One such protein is the microtubule-associated protein tau. Neurodegenerative diseases, in which tau is the major, or predominant, deposited protein, are termed tauopathies. Many tauopathies are associated with movement disorders as part of the presenting syndromes. The most common tauopathies associated with movement disorders are progressive supranuclear palsy, corticobasal degeneration, and frontotemporal dementia with parkinsonism linked to chromosome 17. Less common tauopathies include postencephalic parkinsonism and globular glial tauopathy. All five tauopathies are associated with indistinct clinical syndromes that may have overlapping symptoms. However, some syndromes are more likely to be associated with certain tauopathies. Imaging patterns of abnormalities and genetic aberrations have been described for each of the tauopathies. This chapter focuses on the classification, clinical, and genetic features of these five tauopathies.