MRI measures predict progressive supranuclear palsy

Abstract

Parkinsonism can be caused by idiopathic Parkinson disease (PD), multisystem atrophy (MSA), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and other less common conditions. In the early phases of illness, clinical features may substantially overlap, making accurate diagnosis difficult. To further confound this clinical conundrum, pathologically proven PSP may manifest as 3 distinct clinical phenotypes: PSP–pure akinesia with gait freezing (PSP-PAGF), Richardson syndrome (RS), and PSP parkinsonism (PSP-P).1 Patients with PSP-PAGF have pure akinesia with gait freezing. People with RS have a classic presentation with supranuclear gaze palsy as well as falls and dementia early in the course of the disorder. Those with PSP-P, however, have asymmetric onset, tremor, and moderate initial response to levodopa that may include dopa-induced dyskinesia. Given these overlapping features it is not surprising that early stages of PSP-P can be mistaken for PD, MSA, or even CBD. Standardized clinical diagnostic criteria for PSP known as the National Institute of Neurological Disorders and Stroke (NINDS)–SPSP criteria define probable and possible PSP, with definite PSP requiring histopathology.2 Vertical supranuclear gaze palsy and falls in the first year of disease onset are consistent with probable PSP while supranuclear gaze palsy alone or falls with slowness of vertical saccades are consistent with possible PSP. …