Eyelid movement abnormalities in progressive supranuclear palsy.

We systematically videotaped eyelid movements in a community-based series of 38 patients with progressive supranuclear palsy (PSP). Ten patients (26%) had blepharospasm, "apraxia" of lid opening and/or "apraxia" of lid closing. These patients as a group had more severe upgaze paresis but no greater disease duration than the patients without supranuclear lid dysfunction. Patients used a variety of synkinetic movements to overcome lid-movement abnormalities. One patient displayed "slow blinks," a phenomenon not previously described in PSP. Blink rate in PSP, 3.0/min, was markedly lower than that in patients with Parkinson's disease (PD), 12.5/min, and patients with PSP but not PD increased their blink rate during command versional eye movements.