Progressive supranuclear palsy (PSP) is a brain
disorder in which there is a loss of the ability to move
the eyes from side to side. This is known as a
paralysis of vertical gaze. Dementia occurs in
progressive supranuclear palsy as does dysarthria.
Dementia is a mental disorder characterized by a
significant loss of intellectual and cognitive abilities
without impairment of perception or consciousness.
Dysarthria is a difficulty in speech articulation that
results from an impaired ability to control the muscles
involved in speech. In PSP, the eyelids retract and
the eyes tend to turn outwards. The disorder involves
muscles that receive input from cranial nerves and
mostly affects the face, tongue, and throat.
Actor Dudley Moore had PSP.
Cranial nerves are nerves that emerge from the brain. PSP happens to people in their
60s and it gets worse over time, which is why it is called a progressive disorder. PSP is
called "supranuclear" because it is due to lesions above (which is what "supra" means in
Latin) the primary motor neurons (nerves responsible for movement). The word "nuclear"
is from the Latin word "nucleus" which means "nut" and palsy comes from the Greek word
"paralyein," which means "paralysis." Put it all together and you get "worsening paralysis
above the nut (referring to a nucleus/nerve)." Progressive supranuclear palsy is also
known as Steele-Richardson-Olszewski disease and Steele-Richardson-Olszewski