Diagnosis and Management of Progressive Supranuclear Palsy

Abstract

SUMMARY Progressive supranuclear palsy is one of the rare ‘atypical parkinsonian’ disorders. It is distinguished by its disproportionate postural instability and multiple supranuclear gaze defects emphasizing downgaze limitation. Frontal dementia, bradykinesia, greater rigidity in axial compared with limb muscles, dysarthria and dysphagia also produce major disability, with death after an average of 7 years post-onset. Focal midbrain atrophy, basal ganglia gliosis and iron deposition on MRI assist diagnosis, but present formal diagnostic criteria rely on the history and physical examination of the patient. Experimental biomarkers utilizing cerebrospinal fluid, tau and novel imaging techniques are promising but remain unproven. Unlike Parkinson’s disease, supranuclear palsy usually responds poorly to dopaminergic medication. However, a trial of up to 1200 mg of levodopa per day (with carbidopa) is justified in patients with rigidity and bradykinesia. Amantadine and coenzyme Q-10 may also provide minor symptomatic benefits. Physical measures such as gait assistance and alteration of diet or swallowing technique address the two principal causes of morbidity and mortality in PSP.