Reviewed by Bruno Tota
Parkinson’s disease is a degenerative disorder in the central nervous system that affects motor skills, cognitive processes, and other functions pertaining to the human body. Often characterized by symptoms such as rigidity and postural instability, it may lead to tremors and difficulty in walking, movement, and coordination. Parkinson’s disease has affected over 6.3 million people throughout the world, 1.5 million of whom are American citizens. Although this is a common disorder, there is presently no treatment to permanently cure it. Several medications, such as levodopa and carbidopa, have been successful in providing symptom relief by causing nerve cells to replenish lowered levels of dopamine, a neurotransmitter necessary for the brain to function actively. Sometimes, however, the disease will not respond to any type of drug, and more serious cases may undergo an alternative therapy known as Deep Brain Stimulation, or DBS. While the use of medication on a patient may gradually wear off, scientists have found that DBS has resulted in greater success in overcoming the effects of Parkinson’s disease. This new technique in treating disorders not only prevents most common symptoms in patients but also has been proven to be both safe and scientifically advanced.
Deep Brain Stimulation is a surgical procedure used to treat disabling neurological symptoms that result from disorders like Parkinson’s disease. Currently, it is used only for patients whose symptoms cannot be treated and controlled with medication and has been shown to help reduce the severity of symptoms such as tremor, rigidity, stiffness, slowed movement, and impaired walking. Deep brain stimulation uses a neurostimulator, a surgically implanted, battery-operated device the size of a stopwatch that is similar to a pacemaker. Before the procedure of DBS begins, a neurosurgeon locates the exact area within the brain where electrical nerve signals are causing Parkinson’s disease symptoms; this is where the neurostimulator will be implanted. Once preparations are made for DBS therapy to occur, electrical impulses are sent from the neurostimulator along an extension wire leading into the patient’s brain. This electrical stimulation is applied to areas of the brain controlling movement, in turn blocking any abnormal nerve signals nearby which may cause tremors and other symptoms.
In 2008 and 2009 Frances M. Weaver, Ph.D., of Hines VA Hospital in Illinois, conducted a randomized trial with several colleagues to compare the results of DBS with those from patients undergoing medical therapy for Parkinson’s disease. A total of 255 patients diagnosed with Parkinson’s joined the trial. The participants were randomly chosen to receive either deep brain stimulation treatment or medical therapy that was monitored by movement disorder neurologists. 60 patients received DBS in the subthalamic nucleus of the brain, a central location in the basal ganglia system, which controls motor skills and learning abilities. 61 patients received DBS treatment in the globus pallidus of the brain, located within neural tissue, and 134 patients received medical therapy. After 6 months, researchers discovered that DBS patients gained an average of 4.6 more hours per day without involuntary movement, while the medical therapy group had gained an average increase of 0 hours without involuntary movement during the trial.
Interestingly enough, motor function was not only controlled but also improved significantly in deep brain stimulation patients: 71% of DBS patients experienced major improvement in motor function within 6 months, compared to only 32% of medical therapy patients. Only 3% of DBS patients had clinically worsening scores while 21% of medical therapy patients declined. Overall, patients that had undergone deep brain stimulation experienced significant improvements in regards to their quality of life and motor function skills when compared with patients in the medical therapy group.
Unlike previous surgeries known for treating Parkinson’s disease, Deep Brain Stimulation therapy does not damage healthy brain tissue by destroying nerve cells; rather, it simply blocks electric signals from targeted areas in the brain, making the procedure reversible and adjustable. This is yet another advantage to DBS, since stimulation from the neurostimulator can be easily altered if the patient’s condition changes, even without further surgery. Although most patients may still require certain medications even after undergoing DBS, they generally reduce drug consumption greatly and as a result, experience the side effects associated with Parkinson’s medications less frequently.
Overall, Deep Brain Stimulation therapy is proving to be a beneficial addition to the treatments available for Parkinson’s disease. It has recently garnered attention among research centers and organizations nationwide that are eager to explore its full potential and refine its technique. For instance, the National Institute of Neurological Disorders and Stroke (NINDS) is supporting continued research on DBS to comprehensively determine its safety, reliability, and effectiveness as a treatment for Parkinson’s disease. NINDS-supported scientists are currently trying to determine, in particular, where in the brain DBS surgery is most effective in reducing symptoms. Meanwhile, the US Food and Drug Administration has also approved of DBS for Parkinson’s disease after its potential in alleviating symptoms and reducing drug consumption was demonstrated.
Deep Brain Stimulation therapy is still new to medical technology, but it has shown its potential in becoming a great addition to the treatment of Parkinson’s disease in our society and world today. As for many other medical interventions, DBS will be further improved by development of nano-devices.
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