While waiting for my prescription to be filled at my local Walgreens, I picked up a copy of The Merck Manual of Medical Information. Progressive Supranuclear Palsy: much rarer than Parkinson's disease, causes muscle rigidity, inability to move the eyes and weakness of the throat muscles. ...begins in late middle age with an inability to roll the eyes upward....this disease progresses to severe stiffness and disability. The disease, which destroys the brain's ganglia and brain stem, has no known cause. No completely effective treatment exists, but the drugs used for Parkinson's disease sometimes provide some relief. Sharon H