Magnetic resonance imaging-based volumetric analyses of basal ganglia nuclei and substantia nigra in patients with Parkinson's disease

OBJECTIVE: Parkinson's disease (PD) is associated with well-documented morphological changes in substantia nigra and basal ganglia nuclei. This study evaluates the ability of magnetic resonance imaging to detect these changes and investigates the relationship between severity of clinical findings and degree of morphological change. This correlation may provide valuable information in early diagnosis of PD. METHODS: Sixteen patients with early stage PD, eight patients with advanced PD, and eight normal controls were studied by 3T magnetic resonance imaging. The whole brain volume and the volumes of the caudate, putamen, globus palliclus, and substantia nigra were calculated on three-dimensional reconstructed images. RESULTS: Putamen volume was significantly diminished in patients with early PD and advanced PD compared with that in controls (P < 0.05), and the percentage of atrophy was 12.5 and 26.5%, respectively. The putamen volume was negatively correlated with Hoehn and Yahr staging (r = -0.720, P < 0.001). Pallidal volume was reduced only in advanced PD (P = 0.023). There were no significant differences in total brain, caudate, or substantia nigra among these three groups CONCLUSION: Magnetic resonance imaging-based volumetric measurement is a sensitive method in the assessment of morphological changes of PD in vivo. The putamen atrophy was correlated with the severity of clinical findings. The volumetric measurement of putamen could potentially be a useful indicator of PD in the early stage.