Progressive supranuclear palsy (PSP) (or the Steele-Richardson-Olszewski syndrome, after the Canadian physicians who described it in 1963) is a rare degenerative disease involving the gradual deterioration and death of specific areas of the brain. Males and females are affected approximately equally and there is no racial, geographical or occupational predilection. Approximately 6 people per 100,000 population have PSP. It has been described as a tauopathy.