No relevant midbrain atrophy in Parkinson's disease.
OBJECTIVE
To investigate whether significant midbrain atrophy is present in Parkinson's disease (PD), and if so, whether it can be used as a marker of striatal dopaminergic degeneration.


METHODS
In total, 150 PD patients and 155 controls were scanned with both brain dopamine transporter (DAT) [123I]FP-CIT SPECT and 1.5T MRI. Midbrain atrophy was measured from sagittal MRIs using the midbrain-to-pons ratios. Both striatal region-of-interest-based (Brass) and striatal and extrastriatal voxel-by-voxel-based DAT binding (SPM8) were investigated in relation to midbrain atrophy.


RESULTS
The midbrain-to-pons ratios in PD patients were slightly lower than those in the controls (mean 0.59 vs 0.61, P < 0.05). The ratios did not significantly correlate with striatal or extrastriatal [123I]FP-CIT uptake in controls or patients with PD.


CONCLUSIONS
Mild midbrain atrophy is present in PD and can be detected with MRI. However, the midbrain atrophy in PD is not associated with the level of striatal dopaminergic dysfunction, and midbrain measurements therefore cannot be used as a clinically useful predictor of dopamine function.
Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland. elmama@utu.fi.
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http://orcid.org/0000-0001-7591-1990
E
Mäkinen
Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.|Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland.
J
J
Joutsa
Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.
J
J
Isotalo
Division of Clinical Neurosciences, Turku University Hospital and University of Turku, Turku, Finland.|Turku PET Centre, Turku University Hospital and University of Turku, Turku, Finland.
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V
Kaasinen
D000368:Aged; D001284:Atrophy / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000000981:diagnostic imaging*; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon
Parkinson's disease; dopamine; midbrain atrophy; progressive supranuclear palsy