An autopsy case of postencephalitic parkinsonism of von Economo type: Some new observations concerning neurofibrillary tangles and astrocytic tangles

An autopsied case of postencephalitic parkinsonism of von Economo type with a 71-year duration is reported. Several cases of postencephalitic parkinsonism of von Economo type have been reported in Japan but this is the first reported case from western Japan. The patient was a Japanese man who was 74 years of age at the time of death. He developed encephalitis of unknown etiology at the age of 3 years. The first symptom was antisocial behavior, which developed at 30 years of age. At the age of 40 years, the patient showed progressive parkinsonism. Neuropathological findings disclosed marked neuronal loss with gliosis in the substantia nigra, locus ceruleus, and raphe nuclei, as well as the appearance of neurofibrillary tangles in the aforementioned areas. There were also widespread tuft-shaped astrocytes (Tu-SA) in the central nervous system, including the thalamus. Tuft-shaped astrocytes are considered to represent non-reactive astrocytes because the distributions of neurofibrillary tangles (NFT) and Tu-SA are clearly different. Therefore, the primary astrocytic lesions in postencephalitic parkinsonism of von Economo type may be more widespread. Ultrastructurally, the Tu-SA consisted of straight filaments, 15 nm in width, which formed tight bundles. Ultrastructurally, NFT in this case revealed paired helical filaments but straight filaments, 15 nm in width, which were also found in the neurons of the substantia nigra.