NEURODEGENERATIVE DISORDERS WITH EXTENSIVE TAU-PATHOLOGY - A COMPARATIVE-STUDY AND REVIEW

Many neurodegenerative disorders with onset in mid to late adult life present diagnostic challenges to clinicians and pathologists alike. A distinguishing neuropathological feature has traditionally been the pr esence or absence of neurofibrillary tangles. Recent biochemical and m olecular biological studies have identified the microtubule-binding pr otein tau as the predominant component of these and related inclusions , and have provided powerful new reagents for the study of neurodegene rative diseases. Several diseases previously considered distinct patho physiological entities contain similar tau-immunoreactive lesions, but qualitative and regional anatomical differences in vulnerability can differentiate the disorders. Comparison of tau-immunoreactive lesions in three relatively uncommon neurodegenerative diseases-progressive su pranuclear palsy, Pick's disease, and corticobasal degeneration-illust rates the types of analyses that demonstrate unexpected pathological s imilarities, but also fundamental differences between these disorders. These results have important implications for the differential diagno sis of disorders containing tau-immunoreactive lesions, including Alzh eimer's disease.