MRI evaluation of progressive supranuclear palsy: differentiation from Parkinson's disease and multiple system atrophy

Objectives: To evaluate the magnetic resonance imaging (MRI)-derived parameters in differentiation of patients with progressive supranuclear palsy (PSP) from patients with Parkinson's disease (PD), multiple system atrophy (MSA), and control subjects was aimed. Methods: Thirty-three patients [mean age, 65.21 +/- 4.75 years; PSP (n = 9), MSA (n = 8), PD (n = 6), and control subjects (n = 10)] who have undergone cranial MRI were included in this retrospective study. MRI-derived parameters including areas of midbrain and pons, midbrain area-to-pons area (M/P) ratio, widths of middle cerebellar peduncle (MCP) and superior cerebellar peduncle (SCP), MCP/SCP ratio, magnetic resonance parkinsonism index (MRPI), cerebral interpeduncular angle, and length of midbrain tegmentum were compared in patients with PSP, PD, MSA, and control subjects through the analysis of variance and Kruskal-Wallis tests with Bonferroni correction and Mann-Whitney U test. Results: The length of midbrain tegmentum, midbrain area, SCP, and M/P ratio were found to be lower, while cerebral interpeduncular angle and MRPI were higher in patients with PSP. Pons area, MCP width, and MCP/SCP ratio were found to be lower in patients with MSA. For PSP, cerebral interpeduncular angle has a sensitivity of 100% and specifity of 90%, and MRPI had a sensitivity of 88.9% and specifity of 100% for PSP. Discussion: Several MRI-derived parameters can be used in differentiation of patients with PSP from patients with PD, MSA and control subjects. The cerebral interpeduncular angle and MRPI, which demonstrated higher values in patients with PSP, were more significant for PSP than the other parameters.