Differential Progression of Midbrain Atrophy in Parkinsonism: Longitudinal MRI Study.
To elucidate different patterns of progression of midbrain atrophy in patients with Richardson's syndrome (RS), progressive supranuclear palsy-parkinsonism (PSP-P), and Parkinson's disease (PD) using magnetic resonance imaging (MRI)-based visual rating indexes.



We recruited 12 patients with PSP-RS, 12 with PSP-P, and 23 with PD for whom MRIs had been followed up for at least 2 years (mean ± SD, 4.9 ± 1.6 years) after the initial MRI. MRI-based visual rating indexes were used to estimate midbrain atrophy, including the ratio of the pontine to midbrain tegmental areas (P/M ratio) on a midsagittal image, the length between the interpeduncular fossa and the center of the cerebral aqueduct at the midmammillary-body level (MTEGM) on axial images, and the morning glory sign.



Initially, there were no differences in MRI-based visual rating indexes between PSP-P and PD, while PSP-RS showed a higher P/M ratio and lower MTEGM compared with PSP-P and PD. In PD, the P/M ratio and MTEGM remained stable with disease progression. However, the extent of changes between initial and follow-up indexes was similarly greater for both PSP-RS and PSP-P than for PD. Finally, PSP-P showed a higher P/M ratio and lower MTEGM compared with PD in the follow-up, while PSP-RS still exhibited the most profound changes.



Midbrain atrophy progresses differentially in patients with PSP-RS, PSP-P, and PD. Longitudinal measurements of midbrain atrophy using MRI-based visual rating indexes can help distinguish patients with PSP-P from those with PSP-RS and PD.
Department of Neurology, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
Minho
M
Hwang
Hyunwoo
H
Yang
Younsoo
Y
Kim
Jinyoung
J
Youn
Jongkyu
J
Park
Young Eun
YE
Huh
Hee-Tae
HT
Kim
Jin Whan
JW
Cho
D000368:Aged; D001284:Atrophy; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000000981:diagnostic imaging*; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging*; D011446:Prospective Studies; D012720:Severity of Illness Index; D013494:Supranuclear Palsy, Progressive / Q000000981:diagnostic imaging*