Subthalamic and red nucleus volumes in patients with Parkinson's disease: do they change with disease progression?

To examine a possible correlation between disease progression and the volumes of the subthalamic nucleus (STN) and red nucleus (RN) in patients with Parkinson disease (PD).

Twelve patients with PD (mean time since diagnosis 10.8 +/- 2.9 years) and age-matched 12 normal control subjects were enrolled. The volumes of the STN and RN were measured using 3-dimensional volume reconstructions of stereotactic magnetic resonance images.

The PD and control groups were similar with regard to age and gender. The STN volume was 0.13 +/- 0.01 cm(3) (mean +/- SD) in PD patients and 0.27 +/- 0.01 cm(3) in controls (P < .001). The RN volume was 0.31 +/- 0.02 cm(3) in PD patients and 0.21 +/- 0.02 cm(3) in controls (P = .002). Positive correlations of RN volume with time since diagnosis (P = .004) and disease stage (P = .01) were observed. On average, the STN volumes were 48% smaller and RN volumes 32% larger in PD patients than in control subjects; the volumes of the two nuclei were negatively correlated (r = -0.46; P = .03).

Our results suggest that advanced disease stage and longer disease duration are associated with increased RN volume. STN volume was significantly smaller in Parkinson group. These findings may be useful in estimating disease status and rate of progression, and may also have implications for surgical treatment. Larger studies are needed to validate these results and determine their usefulness.