Immunocytochemical comparison of neurofibrillary tangles in senile dementia of Alzheimer type, progressive supranuclear palsy, and postencephalitic parkinsonism.

Antiserum raised against a two-cycle-purified human brain microtubule fraction that binds specifically to tangles of senile dementia of the Alzheimer type was tested on the subthalamus, basis pontis, and midbrain sections of two patients with progressive supranuclear palsy. Tangles composed of 15 nm straight fibers in these areas showed positive immunolabeling with the antiserum. The labeling tangles appeared as a fibrous meshwork in neuronal cell bodies and occasionally in short segments of axons. Corresponding sections of brains obtained from patients with idiopathic parkinsonism, striatonigral degeneration, and olivopontocerebellar atrophy treated with the same antiserum did not display peroxidase products. Only in the elderly subjects and patients with postencephalitic parkinsonism did the periaqueductal gray and median raphe show occasional cells that reacted positively with the antiserum. Tangles in the substantia nigra of patients with postencephalitic parkinsonism were also recognized by the antiserum. The results suggest that the two morphologically distinct neurofibrillary tangles share their immunological properties with components present in microtubule fractions of normal brain.