Deep brain stimulation involves providing certain areas of the brain with electrical impulses to alleviate certain symptoms in some neurological disorders.
This is a relatively new area of research where therapeutic benefits have been noted in patients with neurological conditions such as Parkinson's disease, chronic pain, dystonia and essential tremors.
Previously, the therapy used to require the creation of permanent lesions in different brain parts to allow for their stimulation, but nowadays a removable pacemaker can be inserted. This means the procedure can be reversed and also controlled to minimize side effects.
Some of the indications for this procedure include:
Parkinson's disease is typically characterized by tremors, muscular rigidity, slowed movement and difficulty in maintaining posture or walking. The basic pathology is destruction and depletion of the dopaminergic neurons in certain areas of the brain that are associated with movement.
Although deep brain stimulation does not cure Parkinson's disease, the technique can be used to ease symptoms to a certain extent.
Patients with the condition who are non-responsive to medication or who develop severe side effects to medication are chosen as candidates for deep brain stimulation, which can improve the efficacy of medication, allow for a decrease in dosage or make a medication regimen more tolerable.
In most cases, the areas of the brain that are targeted include the subthalamic nucleus (STN) and the globus pallidus interna (GPi). Other sites include the caudal zona incerta and the pallidofugal fibers medial to the STN.
In 1997, the Food and Drug Administration (FDA) gave its approval to use deep brain stimulation for the treatment of essential tremor.
Tourette's syndrome is characterized by several movement disorders along with habitual tics, grunts and behavioral problems. Deep brain stimulation is still experimental in patients with Tourette's syndrome.
Reviewed by Sally Robertson, BSc