Manual MRI morphometry in Parkinsonian syndromes.

BACKGROUND: Several morphometric magnetic resonance imaging parameters may serve for differential diagnosis of parkinsonism. The objective of this study was to identify which performs best in clinical routine.

METHODS: We acquired multicentric magnetization-prepared rapid gradient echo sequences in patients with Parkinson's disease (n=204), progressive supranuclear palsy (n=106), multiple system atrophy-cerebellar, (n = 21); multiple system atrophy-parkinsonian (n = 60), and healthy controls (n = 73), performed manual planimetric measurements, and calculated receiver operator characteristics with leave-one-out cross-validation to propose cutoff values.

RESULTS: The midsagittal midbrain area was reduced in PSP versus all other groups (P < 0.001). The midsagittal pons area was reduced in MSA-cerebellar, MSA-parkinsonian, and PSP versus PD patients and healthy controls (P < 0.001). The midbrain/pons area ratio was lower in PSP (P < 0.001) and higher in MSA-cerebellar and MSA-parkinsonian versus PD and PSP (P < 0.001).

CONCLUSIONS: The midsagittal midbrain area most reliably identified PSP, the midsagittal pons area MSA-cerebellar. The midbrain/pons area ratio differentiated MSA-cerebellar and PSP better than the magnetic resonance-Parkinson index. © 2017 International Parkinson and Movement Disorder Society.