Movement-related symptoms of Parkinson's disease and other neurological conditions are caused by faulty electrical signals in the areas of the brain that control movement. The deep brain stimulation (DBS) therapy is a new "high-tech" treatment for a number of neurologic disorders. DBS in select brain regions can provide remarkable therapeutic benefits for otherwise treatment-resistant movement disorders such as PD, tremor and dystonia.
The surgery involves a thin electrode being implanted within a specific area of the brain and connected to a battery- operated neurostimulator (similar to a pacemaker). The neurostimulator is surgically placed in the chest wall usually one to two weeks after electrode placement.Once in place, the device is programmed to deliver a mild electrical pulse to the area of the brain that controls the abnormal movements associated with their disorder. By adjusting the stimulation, patients can experience relieved or decreased symptoms of tremor, rigidity, slowness of movement, stiffness, and balance.
The surgery is most beneficial for two types of Parkinson's disease (PD) patients: (1) patients with uncontrollable tremor for which medications have not been effective and (2) patients with symptoms that are well treated with medications but who experience severe motor fluctuations, including wearing off and dyskinesias, despite attempts to control such fluctuations with changes in medications.
Unlike previous surgeries for PD, DBS does not damage healthy brain tissue by destroying nerve cells. Instead, the procedure blocks electrical signals from targeted areas in the brain. Thus, if newer, more promising treatments develop in the future, the DBS procedure can be reversed. Also, stimulation from the neurostimulator is easily adjustable-without further surgery-if the patient's condition changes.
Although most patients still need to take medication after undergoing DBS, many PD symptoms improve after DBS and many times daily dose of anti-parkinson's medications is reduced. The amount of reduction varies from patient to patient but can be noticeably reduced in most patients. The reduction in dose of medication leads to a significant improvement in side effects like dyskinesias. In some cases, the stimulation itself can suppress dyskinesias without a reduction in medication.
DBS is also used to treat Essential Tremor. In many cases, the tremor is mild enough to be effectively treated with medication. However, in severe cases medications may not be effective and tremor can become profoundly disabling. DBS reduces essential tremor and improves patients' ability to perform daily activities.
DBS can be performed for both generalized and focal dystonia. Dystonia can be very disabling due to impairment of motor skills as well as significant pain. There are multiple medications along with botulinum toxin that can be effective to treat dystonia. When medications or other non-surgical therapies are not successful deep brain stimulation can be a very effective treatment.