Parkinson's Disease

Deep brain stimulation (DBS) is a surgical treatment involving the implantation of a medical device called a brain pacemaker, which sends electrical impulses to specific parts of the brain. DBS in select brain regions has provided remarkable therapeutic benefits for otherwise treatment-resistant movement and affective disorders such as chronic pain, Parkinson’s disease, tremor and dystonia. Despite the long history of DBS, its underlying principles and mechanisms are still not clear. DBS directly changes brain activity in a controlled manner, its effects are reversible (unlike those of lesioning techniques) and is one of only a few neurosurgical methods that allows blinded studies.

DBS leads are placed in the brain according to the type of symptoms to be addressed. For non-Parkinsonian essential tremor the lead is placed in the ventrointermedial nucleus (VIM) of the thalamus. For dystonia and symptoms associated with Parkinson's disease (rigidity, bradykinesia /akinesia and tremor), the lead may be placed in either the globus pallidus or subthalamic nucleus. All three components are surgically implanted inside the body. The right side of the brain is stimulated to address symptoms on the left side of the body and vice versa.

Parkinson's Disease is a neurodegenerative disease whose primary symptoms are tremor, rigidity, bradykinesia and postural instability.  At present, the procedure is used only for patients whose symptoms cannot be adequately controlled with medications, or whose medications have severe side effects. By sending high frequency electrical impulses into specific areas of the brain it can mitigate symptoms and/or directly diminish the side effects induced by Parkinsonian medications, allowing a decrease in medications, or making a medication regimen more tolerable. Traditionally, the two most common sites are the subthalamic nucleus (STN) and the globus pallidus interna (GPi).