What's progressive supranuclear palsy?
Progressive supranuclear palsy (PSP) is a rare degenerative neurological disorder characterized by loss of balance when walking, loss of control of voluntary eye movement and other voluntary muscle activity (akinesia), abnormal rigidity (spasticity), postural instability, speech difficulties (dysarthria), and problems related to swallowing and eating (dysphagia). Affected individuals frequently experience personality changes and cognitive impairment. For example, the ability to recognize, judge, and perceive may be affected. The exact cause of progressive supranuclear palsy is unknown. Progressive supranuclear palsy is a disease of middle age. Symptoms usually begin in the 60s, rarely before age 45 or after age 75. Men develop PSP more often than women do. It affects three to four people per million each year.