Subcortical neurofibrillary tangles, neuropil threads, and argentophilic glial inclusions in corticobasal degeneration

This report concerns an autopsy case of corticobasal degeneration (CBD). The patient was a 64-year-old woman with slowly progressing clumsiness and gait disturbance who died approximately 7 years after the onset of symptoms. The salient neuropathological findings were focal loss of neurons of the cerebral cortex, ballooned neurons and gliosis of the subcortical white matter, thalamus, and basal ganglia. In addition, there were marked neuronal loss and gliosis in the substantia nigra. The ballooned neurons were positively immunostained for phosphorylated neurofilament, αB-crystallin and synaptophysin; staining for the latter was intraneuronal. The examination of silver impregnated and Tau immunostained preparations revealed numerous basal neurofibrillary tangles, neuropil threads, and glial inclusions; their presence was most pronounced in the brainstem tegmentum, basal ganglia, and thalamus. Neurofibrillary tangles consisting of straight tubules with a diameter of approximately 13 - 15 nm and constricted tubules were identified in the substantia nigra. The results of the present study indicate that the cytopathology of the subcortical gray matter and brainstem in CBD patients resembles that of progressive supranuclear palsy.