Abstract
Progressive supranuclear palsy is a disorder of tau protein aggregation. Its clinical
spectrum is now known to be wider than originally described, with a phenotype resembling
Parkinson disease accounting for a third of cases. However, at least half of the patients
with PSP exhibit the classic bradykinesia with disproportionate postural instability,
erect posture with nuchal rigidity, frontal behavioral and cognitive changes, vertical
gaze palsy, and other disabling brainstem deficits. Nonmendelian genetic risk factors
exist, but PSP is almost entirely sporadic, with a prevalence of five to six persons
per 100,000, mean onset age of 63, and median survival of 7 years. Clinical diagnostic
criteria with excellent specificity and a clinical rating scale sensitive to progression
are available. Diagnosis remains clinical, although magnetic resonance imaging and
cerebrospinal fluid measures are showing promise as early-stage screening tools. Multiple
candidate neuroprotective medications have proven ineffective to date. Treatment remains
supportive, although coenzyme Q-10 has shown preliminary symptomatic efficacy and
levodopa may provide transient, modest benefit.
Keywords
progressive supranuclear palsy - brainstem - tau - parkinsonism - frontal dementia
