Background: Progressive supranuclear palsy (PSP) is the commonest atypical parkinsonian (“Parkinson-plus”) syndrome and a 4-repeat tauopathy that is frequently misdiagnosed as idiopathic Parkinson disease early in its course. MRI of the brainstem demonstrates a group of highly specific morphological and planimetric signs that reflect the midbrain-predominant atrophy of PSP.

Objective: To illustrate the characteristic MRI features of PSP in a patient carrying a non-specific clinical label of atypical parkinsonism, and to review the systematic imaging approach used to differentiate PSP from multiple system atrophy (MSA) and corticobasal degeneration (CBD).

Case summary: A 60-year-old hypertensive man presented with acute dysphagia and dysarthria of two days’ duration on a background of an eighteen-month history of progressive gait disturbance and a prior clinical diagnosis of atypical parkinsonism. MRI of the brain demonstrated midbrain tegmental atrophy producing the hummingbird (penguin) sign on midsagittal T1, the morning-glory / Mickey-Mouse configuration of the midbrain on axial images, thinning of the superior cerebellar peduncles and third-ventricular widening, with a preserved pons.