The Occurrence of "Typical" MRI Findings in Progressive Supranuclear Palsy and Multiple System Atrophy - a Retrospective Pilot Study

Objectives: Conventional MRI findings are usually normal in patients with Parkinson's disease, whereas they are believed to reveal characteristic abnormalities in patients with other parkinsonian syndromes. This difference provides a potential for using objective neuroradiological criteria in differential diagnosis. Methods: In this pilot study, MRI examinations of the brain were retrospectively assessed in 10 patients (7 females, 3 males: aged 59-71, mean 65 +/- 4.2 years) suffering from PSP (6 patients) and MSA (4 patients), confirmed through clinical, laboratory, electrophysiological and CSF findings. The areas of midbrain tegmentum and pons were inspected with particular attention and the following "typical" MRI signs were sought: "morning glory" sign, "hot cross bun" sign, "panda face" sign and "standing penguin silhouette" sign, as well as hypo- or hyperintensities in the posterolateral putamen (in 12 and FLAIR images). Results: In all the patients with PSP, the "standing penguin silhouette" appeared, while the "morning glory" sign was observed in only one patient with PSP. In contrast, all patients with MSA had hypo- and hyperintensities in the posterolateral putamen in T2 and FLAIR scans. The "hot cross bun" sign was found in one patient. Conclusion: We confirmed the presence of midbrain atrophy as a typical neuro-imaging feature ("standing penguin silhouette") in PSP. The "standing penguin silhouette" appears to be more sensitive than the "morning glory" sign. Patients with MSA manifested signal changes in the posterolateral putamen in 12 and FLAIR images instead.