Magnetic resonance imaging study of basal ganglia volumes in patients with Parkinson′s disease

Objective To explore the structural changes of basal ganglia (subcortical nuclei of cerebral hemisphere) in Parkinson′s disease (PD) based on magnetic resonance imaging (MRI) and their relationship with clinical status, and to find neuroimaging biomarkers that are valuable for early diagnosis and disease progression monitoring in PD. Methods Three-dimensional-T1WI and T2WI were applied to 54 PD patients (35 in tremor-dominant PD group, 19 in akinetic-rigid-dominant PD group) and 35 healthy controls using 3.0 T MRI scanner. Voxel-based morphometry was used to investigate the volume changes of basal ganglia (subcortical nuclei of cerebral hemisphere, including caudate nucleus, putamen, and globus pallidus). Results Compared with the controls (caudate nucleus: left (6.94±1.00) mm3, right (6.93±0.88) mm3; putamen: left (5.64±0.69) mm3, right (6.03±0.86) mm3; globus pallidus: left (3.49±0.26) mm3, right (3.60±0.25) mm3, PD patients (caudate nucleus: left (5.99±1.78) mm3, right (6.11±1.65) mm3; putamen: left (4.99±1.50) mm3, right (5.56±1.68) mm3; globus pallidus: left (3.12±0.72) mm3, right (3.23±0.72) mm3) exhibited volume reduced in bilateral caudate nuclei (left t=2.871, P=0.005; right t=3.045, P=0.003), left putamen (t=2.773, P=0.007), and bilateral globus pallidus (left t=3.439, P=0.001; right t=3.493, P=0.001). Early stage of PD patients exhibited these changes. In addition, atrophy was showed mainly in left putamen (t=2.136, P=0.038) and globus pallidus (left t=2.683, P=0.010; right t=2.637, P=0.011) in the early stage, while in the later stage, caudate nucleus volume reduction (left t=3.260, P=0.002; right t=3.089, P=0.003) was also found. Moreover, no significant differences were found between tremor-dominant PD group and akinetic-rigid-dominant PD group. However, bilateral volume changes of basal ganglia in PD patients were not explicitly relevant to age, gender, Mini-Mental State Examination score, levodopa equivalent doses, disease duration, Hoehn-Yahr stages, Unified Parkinson′s Disease Rating Scale-Ⅲ score, Hamilton Rating Scale for Depression score or Hamilton Rating Scale for Anxiety score. Conclusions The phenomenon of reduced basal ganglia volume was found in patients with PD. The measurement of basal ganglia volume by MRI could be an objective way for early diagnosis of PD. Key words: Parkinson disease; Basal ganglia; Nucleus volume; Magnetic resonance imaging