CORTICAL BALLOONED NEURONS IN PROGRESSIVE SUPRANUCLEAR PALSY

We report the presence of ballooned neurons (BNs) in the cerebral cort ex of patients with progressive supranuclear palsy (PSP) using immunoh istochemistry for phosphorylated neurofilament in addition to standard histologic staining methods. In six of the nine patients studied, BNs were seen in the cerebral cortex. In two of these six patients, BNs w ere abundant and cortical degeneration was present in the precentral c ortex. On immunohistochemistry, BNs were positive for phosphorylated n eurofilament and alpha B crystallin, and some BNs were positive for ub iquitin and tan protein. The immunohistochemical staining pattern was similar to that of the BNs seen in other diseases, such as corticobasa l degeneration. The presence of cortical BNs does not differentiate PS P from corticobasal degeneration although BNs are fewer in the patient s with PSP when cortical degeneration is not present.