Arm levitation in progressive supranuclear palsy.

Spontaneous arm levitation (SAL) is well-recognized in cortical-basal ganglionic degeneration, but not in other neurodegenerative diseases. We report six cases of progressive supranuclear palsy (PSP) with SAL. Pathologic examination in four revealed the classic features of PSP with additional areas of focal cortical degeneration. We conclude that SAL can occur in PSP and its occurrence may be a marker of cortical degeneration.