Karimi M et al. (2008) Subthalamic nucleus stimulation-induced regional blood flow responses correlate with improvement of motor signs in Parkinson disease. Brain [doi: 10.1093/brain/awn179]

Deep brain stimulation (DBS) of the subthalamic nucleus has been shown to improve motor symptoms associated with Parkinson disease (PD), but the mechanism of this action is unclear. Previous studies have demonstrated that DBS of the subthalamic nucleus alters regional cerebral blood flow (rCBF) throughout the brain. In a new study, Karimi et al. investigated whether changes in blood flow in specific regions of the brain leads to improvements in different motor functions in PD.

Data were assessed from 31 patients with PD (average age 61 ± 10 years, average duration since diagnosis 14 ± 8 years) who underwent PET scans to measure rCBF responses to bilateral DBS of the subthalamic nucleus. The scans revealed that, after DBS, rCBF was increased in the bilateral thalami and right midbrain and decreased in the right premotor cortex. Improvement in motor symptoms occurred in all patients after administration of DBS. Rigidity improved by 62% and bradykinesia by 44%, and these effects correlated with decreased rCBF in the supplementary motor area, and increased rCBF in the thalamus, respectively. Postural stability improved by 56%, an effect that was correlated with decreased rCBF in the pedunculopontine nucleus region.

The authors suggest that the relationship between changes in rCBF in specific regions of the brain and improvements in selected motor functions supports the use of targeted treatments in PD.