DEEP BRAIN STIMULATION IN INDIA
What is Deep Brain Stimulation for Parkinson’s disease ?
Deep brain stimulation (DBS) is a surgical procedure used to treat a variety of disabling neurological symptoms-most commonly the debilitating symptoms of Parkinson’s disease (PD), such as tremor, rigidity, stiffness, slowed movement, and walking problems. The procedure is also used to treat essential tremor, a common neurological movement disorder. At present, the procedure is used only for patients whose symptoms cannot be adequately controlled with medications.
DBS uses a surgically implanted, battery-operated medical device called a neurostimulator-similar to a heart pacemaker and approximately the size of a stopwatch-to deliver electrical stimulation to targeted areas in the brain that control movement, blocking the abnormal nerve signals that cause tremor and PD symptoms.
Before the procedure, a neurosurgeon uses magnetic resonance imaging (MRI) or computed tomography (CT) scanning to identify and locate the exact target within the brain where electrical nerve signals generate the PD symptoms. Some surgeons may use microelectrode recording-which involves a small wire that monitors the activity of nerve cells in the target area-to more specifically identify the precise brain target that will be stimulated. Generally, these targets are the thalamus, subthalamic nucleus, and globus pallidus.
Is there any treatment ?
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. Some people describe the stimulator adjustments as “programming.”
In deep brain stimulation electrodes are connected by wires to a type of pacemaker device (called an impulse generator, or IPG) implanted under the skin of the chest, below the collarbone. Once activated, the device sends continuous electrical pulses to the target areas in the brain, blocking the impulses that cause tremors. This has the same effect as thalamotomy or pallidotomy surgeries without actually destroying parts of the brain.
The IPG can easily be programmed using a computer that sends radio signals to the device. Patients are given special magnets so they can externally turn the IPG on or off.
Depending on use, the stimulators may last three to five years. IPG replacement procedure is relatively simple. The stimulation can be turned on or off by the patient with a hand-held magnet or an access control device.
The procedure is lengthy, and the patient will require a short hospital stay afterward to recover from the surgery. Following the procedure itself, the patient meets several times with the neurologist to adjust the stimulation. The pulse generator is programmable, and can be fine-tuned to the patient’s particular needs. This can provide a higher degree of symptom relief than lesioning surgeries, but requires repeated visits to the neurologist. Pulse generator batteries must be replaced every three to five years. This is done with a small incision as an outpatient procedure. Since the generator is in the chest area, no additional brain surgery is required.
The patient’s medications are adjusted after surgery, with a reduction in levodopa likely in most patients who receive DBS of the subthalamic nucleus.