brain, spinal cord, and nerve disorders
Progressive Supranuclear Palsy (PSP)
Introduction
Progressive supranuclear palsy is characterized by slow movements, muscle stiffness (rigidity), problems moving the eyes, and a tendency to fall backward. Progressive supranuclear palsy progresses faster and results in more severe muscle rigidity and disability than Parkinson disease. The diagnosis is based on symptoms, a doctor's evaluation, and magnetic resonance imaging. No effective treatment exists, but drugs used to treat Parkinson disease sometimes provide temporary relief. (See also Overview of Movement Disorders .) Progressive supranuclear palsy, which is much rarer than Parkinson disease, affects many parts of the brain, particularly the basal ganglia and the brain stem. The basal ganglia help initiate and smooth out intended (voluntary) movements, suppress unintended (involuntary) movements, and coordinate changes in posture. The brain stem regulates critical body functions, such as breathing, heart rate, and swallowing, and helps adjust posture. Brain cells in these areas degenerate, but why they do is usually unknown. The basal ganglia are collections of nerve cells located deep within the brain. They include the following: Caudate nucleus (a C-shaped structure that tapers to a thin tail) Putamen Globus pallidus (located next to the putamen) Subthalamic nucleus Substantia nigra The basal ganglia help initiate and smooth out muscle movements, suppress involuntary movements, and coordinate changes in posture. 