Tauopathies

Tauopathies The term “tauopathy” defines a group of heterogeneous pathological disorders that are defined by the deposition of the microtubule-associated protein tau. A number of specific tauopathies have been described, which differ from one another by the distribution and morphological appearance of the protein-containing inclusions [1]. The most common tauopathies include progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), Pick’s disease (PiD), and those cases where tau deposition is associated with mutations in the microtubule-associated protein tau (<italic>MAPT</italic>) gene on chromosome 17. Over 44 different pathogenic mutations in the tau gene have been identified in over 100 families, and include missense mutations, silent mutations, single codon deletions, and intronic mutations. Rarer tauopathies include argyrophilic grain disease, globular glial tauopathy, Niemann–Pick type C, postencephalitic parkinsonism (PEP), subacute sclerosing panencephalitis (SSPE), and tangle-dominant dementia. Clinical syndromes associated with tauopathies It was traditionally thought that each tauopathy was associated with a specific clinical syndrome, although recent clinicopathological studies have demonstrated that this is not the case, and that, in fact, the clinical syndromes associated with these pathologically defined disorders are heterogeneous [2]. The tauopathies that are typically associated with motor syndromes, and hence will be the focus of this chapter, are PSP, CBD, and MAPT mutations (see Table 12.1 for pathological characteristics).