Altered diffusion in the frontal lobe in Parkinson disease.
OBJECTIVE
Parkinson disease (PD) is characterized by basal ganglia abnormalities. However, there are neurodegenerative changes in PD that extend beyond the basal ganglia and that are not sufficiently evaluated with standard MR imaging. The aim of this study was to characterize whole-brain gray matter (GM) and white matter (WM) changes in PD by using diffusion tensor imaging (DTI).


METHODS
Thirteen control and 12 subjects with nondemented PD were examined by using DTI and 3D anatomic T1-weighted images. Statistical parametric mapping analyses of DTI and anatomic images were performed. Patients were evaluated with a variety of neurocognitive measures and the Unified Parkinson's Disease Rating Scale (UPDRS) OFF (cessation of medication) and ON (taking medications as normal) their antiparkinsonian medications.


RESULTS
The PD participants had dopa-responsive features as ascertained by the UPDRS OFF versus ON medications and had no cognitive impairment. Decreased fractional anisotropy (FA) was observed in subjects with PD bilaterally in the frontal lobes, including the supplementary motor area, the presupplementary motor area, and the cingulum. There were no significant differences in mean diffusivity or GM/WM attenuation between PD subjects and controls.


CONCLUSIONS
Statistical parametric mapping analysis of DTI showed changes in FA in frontal areas without volume loss. These results confirm that the neurodegenerative process extends beyond the basal ganglia in PD.
Karagulle Kendi
A T
AT
Department of Radiology, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minn., USA.
Lehericy
S
S
Luciana
M
M
Ugurbil
K
K
Tuite
P
P
D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005625:Frontal Lobe / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D009474:Neurons / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity