Glial abnormalities in progressive supranuclear palsy and corticobasal degeneration

Objective To study pathologic features of glial cells in progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD) and to explore their pathologic significance. Methods Brain tissues from 2 cases with PSP and 3 cases with CBD, all confirmed by autopsies, were examined by routine neuropathologic methods, Gallyas-Braak staining and tau immunostaining. Brain tissues from 6 Alzheimer's disease cases, 4 cases with Parkinson's disease and 6 elderly with no neurologic abnormality were used as controls. Results Gallyas-Braak staining demonstrated tuft-shaped astrocytes and coiled-body oligodendroglial cells in the brain tissues of 2 cases with PSP and 3 cases with CBD. The tuft-shaped astrocytes appeared prominently in the frontal and parietal cortex, basal ganglia and grey matter of the brainstem. The coiled-body oligodendroglial cells were distributed widely in the white matter of the frontal and parietal lobes, basal ganglia, brainstem and cerebellum. However, astrocytic plaques, composed of degenerative stubby processes with radiating arrangement, only appeared in the frontal, parietal and cingular cortex, as well as in the striatum of 3 cases with CBD. The astrocytic plaques and tuft-shaped astrocytes coexisted in the same areas, including parietal and cingular cortex and striatum, in CBD. All these glial abnormalities showed tau-positive immunoreaction not found in control cases. Conclusions The tuft-shaped astrocytes and coiled-body oligodendroglial cells are common glial morphologic features of both PSP and CBD. Astrocytic plaques are also characteristically seen in CBD.