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Distinct progression pattern of susceptibility MRI in the substantia nigra of Parkinson's patients
Author(s) -
Du Guangwei,
Lewis Mechelle M.,
Sica Christopher,
He Lu,
Connor James R.,
Kong Lan,
Mailman Richard B.,
Huang Xuemei
Publication year - 2018
Publication title -
movement disorders
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.352
H-Index - 198
eISSN - 1531-8257
pISSN - 0885-3185
DOI - 10.1002/mds.27318
Subject(s) - substantia nigra , pars compacta , pars reticulata , parkinson's disease , medicine , pathology , psychology , disease
Background: Susceptibility MRI may capture Parkinson's disease‐related pathology. This study delineated longitudinal changes in different substantia nigra regions. Methods: Seventy‐two PD patients and 62 controls were studied at both baseline and after 18 months with MRI. R2* and quantitative susceptibility mapping values from the substantia nigra pars compacta and substantia nigra pars reticulata were calculated. Mixed‐effects models compared controls with PD or PD subgroups having different disease durations: early (<1 year), middle (<5 years, middle‐stage PD), and late (>5 years, late‐stage PD). Pearson's correlation assessed associations between imaging and clinical measures. Results: At baseline, R2* and quantitative susceptibility mapping were higher in both the substantia nigra pars compacta and substantia nigra pars reticulata in all PD patients (group effect, P ≤ 0.003). Longitudinally, the substantia nigra pars compacta R2* showed a faster increase in PD compared with controls (time × group, P = 0.002), whereas quantitative susceptibility mapping did not ( P = 0.668). The substantia nigra pars reticulata R2* and quantitative susceptibility mapping did not differ between PD and controls (time × group, P ≥ 0.084), although both decreased longitudinally (time effect, P ≤ 0.004). Baseline substantia nigra pars compacta R2* was higher in all PD subgroups (group, P ≤ 0.006), but showed a significantly faster increase only in later‐stage PD (time × group, P < 0.0001) that correlated with changes in nonmotor symptoms ( r = 0.746, P = 0.002). Baseline substantia nigra pars reticulata quantitative susceptibility mapping was higher in middle‐stage PD and later‐stage PD (group, P ≤ 0.002), but showed a longitudinal decrease (time × group, P = 0.004) only in later‐stage PD that correlated with changes in motor signs ( r = 0.837, P < 0.001). Conclusion: Susceptibility MRI revealed distinct patterns of PD progression in the substantia nigra pars compacta and substantia nigra pars reticulata. The different patterns are particularly clear in later‐stage patients. These findings may resolve past controversies and have implications in the pathophysiological processes during PD progression. © 2018 International Parkinson and Movement Disorder Society