Progressive Supranuclear Palsy
Progressive supranuclear palsy is a rare, degenerative CNS disorder that progressively impairs voluntary eye movements and causes bradykinesia, muscular rigidity with progressive axial dystonia, pseudobulbar palsy, and dementia. Diagnosis is clinical. Treatment focuses on relieving symptoms.
(See also Overview of Movement and Cerebellar Disorders.)
The cause of progressive supranuclear palsy is unknown.
Neurons in the basal ganglia and brain stem degenerate; neurofibrillary tangles containing an abnormally phosphorylated tau protein are also present. Multiple lacunar strokes in the basal ganglia and deep white matter can resemble progressive supranuclear palsy; however, cerebrovascular disease is nondegenerative and progresses more gradually.
Symptoms of progressive supranuclear palsy usually begin in late middle age.
The first symptom may be
Voluntary eye movements, particularly vertical, are difficult, but reflexive eye movements are unaffected.
Movements are slowed, muscles become rigid, and axial dystonia develops. Patients tend to fall backward.
Dysphagia and dysarthria with emotional lability (pseudobulbar palsy) are common. Resting tremor may develop.
Dementia eventually occurs.
Many patients become incapacitated within about 5 yr and die within about 10 yr.
Diagnosis of progressive supranuclear palsy is clinical.
MRI is usually done to exclude other disorders. In advanced cases, MRI shows a characteristic decrease in midbrain size that is best seen on midsagittal views and that causes the midbrain to be shaped like a hummingbird or emperor penguin. On axial views, the midbrain may resemble a morning glory (1).
Treatment of progressive supranuclear palsy focuses on relieving symptoms but is unsatisfactory. Occasionally, levodopa and/or amantadine partially relieve rigidity. Physical and occupational therapy may help improve mobility and function and reduce the risk of falls.
Because progressive supranuclear palsy is fatal, patients should be encouraged to prepare advance directives soon after the disorder is diagnosed. These directives should indicate what kind of medical care people want at the end of life.