Deep brain stimulation

Deep brain stimulation (DBS) is a neurosurgical procedure involving the placement of a medical device called a neurostimulator, which sends electrical impulses, through implanted electrodes, to specific targets in the brain (the brain nucleus) for the treatment of movement disorders, including Parkinson's disease, essential tremor, dystonia, and other conditions such as obsessive-compulsive disorder (OCD) and epilepsy. While its underlying principles and mechanisms are not fully understood, DBS directly changes brain activity in a controlled manner. DBS has been approved by the Food and Drug Administration as a treatment for essential tremor and Parkinson's disease (PD) since 1997. DBS was approved 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 for various affective disorders, including major depression. It is one of few neurosurgical procedures that allow blinded studies. DBS is used to manage some of the symptoms of Parkinson's disease that cannot be adequately controlled with medications. PD is treated by applying high-frequency (> 100 Hz) stimulation to three target structures, namely to the ventrolateral thalamus, internal pallidum, and subthalamic nucleus (STN) to mimic the clinical effects of lesioning. It is recommended for people who have PD with motor fluctuations and tremors inadequately controlled by medication, or to those who are intolerant to medication, as long as they do not have severe neuropsychiatric problems. Four areas of the brain have been treated with neural stimulators in PD. These are the globus pallidus internus, thalamus, subthalamic nucleus and the pedunculopontine nucleus. However, most DBS surgeries in routine practice target either the globus pallidus internus or the Subthalamic nucleus. DBS of the globus pallidus internus reduces uncontrollable shaking movements called dyskinesias. This enables a patient to take adequate quantities of medications (especially levodopa), thus leading to better control of symptoms.