Deep brain stimulation

Deep brain stimulation (DBS) is a type of neurostimulation therapy in which an implantable pulse generator is surgically implanted below the skin of the chest and connected by leads to the brain to deliver controlled electrical impulses. These charges therapeutically disrupt and promote dysfunctional nervous system circuits bidirectionally in both ante- and retrograde directions. Though first developed for Parkinsonian tremor, the technology has since been adapted to a wide variety of chronic neurologic disorders.

The usage of electrical stimulation to treat neurologic disorders dates back thousands of years to ancient Greece and dynastic Egypt. The distinguishing feature of DBS, however, is that by taking advantage of the portability of lithium-ion battery technology, it is able to be used long term without the patient having to be hardwired to a stationary energy source. This has given it far more practical therapeutic application as compared its earlier non mobile predecessors.

The exact mechanisms of DBS are complex and not fully understood, though it is thought to mimic the effects of lesioning by disrupting pathologically elevated and oversynchronized informational flow in misfiring brain networks. As opposed to permanent ablation, the effect can be reversed by turning off the DBS device. Common targets include the globus pallidus, ventral nuclear group of the thalamus, internal capsule and subthalamic nucleus. It is one of few neurosurgical procedures that allows blinded studies, though most studies to date have not taken advantage of this discriminant.

Since its introduction in the late 1980s, DBS has become the major research hotspot for surgical treatment of tremor in Parkinson's disease, and the preferred surgical treatment for Parkinson's, essential tremor and dystonia. Its indications have since extended to include obsessive-compulsive disorder, refractory epilepsy, chronic pain, Tourette's syndrome, and cluster headache. In the past three decades, more than 244,000 patients worldwide have been implanted with DBS.

DBS has been approved by the Food and Drug Administration as a treatment for essential and Parkinsonian tremor since 1997 and for Parkinson's disease since 2002. It was approved as a humanitarian device exemption for dystonia in 2003, obsessive–compulsive disorder (OCD) in 2009 and epilepsy in 2018. DBS has been studied in clinical trials as a potential treatment for chronic pain, affective disorders, depression, Alzheimer's disease and drug addiction, amongst others.