Thalamic Deep Brain Stimulation for Parkinson’s Disease

With recent advances in neuroimaging and neurosurgical techniques as well as better understanding of functional motor brain circuits, there is increasing evidence that electrical deep brain stimulation (DBS) can be a powerful and safe therapeutic option for medically intractable movement disorders and neuropsychiatric diseases. For more than half a century, the ventrolateral (VL) nucleus of the thalamus has been an anatomical target for stereotactic surgeries (e.g., ablation surgery and DBS) treating various types of tremors, including Parkinson’s disease (PD)-associated tremor. The VL nucleus comprises the nucleus ventralis intermedius (Vim) and the nucleus ventralis oralis (Vo) (Hassler, 1959). Currently, thalamic DBS is widely used because of its reversibility, adjustability, and low level of invasiveness. Thalamic DBS of the Vim nucleus can effectively alleviate parkinsonian tremor; however, it does not provide consistent improvement in parkinsonian symptoms other than tremor. Therefore, its use is limited to patients with tremorpredominant PD, in whom other motor symptoms are not disabling. In this review, we will survey the rationale and current use of thalamic DBS in the treatment of PD.