The Other Side of Deep Brain Stimulation in PARKINSON’S DISEASE
Deep Brain Stimulation (DBS) for PARKINSON’S DISEASE has now been a regular method of treatment for almost 25 years. Improvements in technique and the appliances used have also come a long ways. DBS has been used to treat symptoms that resist treatment with the available drugs with mostly excellent results. But as the recipient’s age and the disease progresses, DBS can have some negative effects.
It is estimated that over 100,000 people with PARKINSON’S DISEASE all over the world have received DBS for treatment of motor symptoms of PD. The results of long term follow up data are now becoming available. Some patients have experienced significant and recurring infections that have greatly impacted their quality of life. Often the infections stem from the generator device implanted under the skin on the chest. Batteries die and generators need to be replaced and because of repeated replacements, infection is more of a risk. Some infections have been so severe that the entire device must be removed and the patient experiences worsening symptoms of PD.
As time passes, the disease progresses and the results of the DBS become less beneficial. Cognitive decline in the patient and an inability to care for themselves properly make replacing the batteries or re-programming the generator difficult choices. Family members and caregivers often have the burden to make these difficult decisions and often the best solution is the complete removal of the device. This is not without a physical expense of worsening symptoms as well as the economic impact of the cost of more surgery.
Dystonia and dyskinesia that were once well controlled by the DBS worsen with the progression of the disease and the DBS can no longer be programmed to eliminate them. When patients reach this point, they have to be considered for nursing home care, especially if there are cognitive issues involved. There have been cases where the device was completely removed and the patients experienced relief of the dystonia or dyskinesia and were able to return to their home with a great relief of the burden to return frequently for multiple battery replacements or adjustments to the spouse/caregiver.
DBS was a great replacement for the then popular lesioning of the subthalamic nucleus or globus pallidus. Technologies have advanced, stereotactic and functional neurosurgeries have improved and lesioning may be an appropriate alternative, even after removal of the DBS device. While each carries certain risks and benefits, the benefit of pallidotomy on motor symptoms requires less exposure to the risk of infection than DBS. Unilateral pallidotomy in patients who have had the DBS hardware removed, either for infections or cognitive decline, have shown good control of motor symptoms such as tremor, rigidity and dyskinesias. Depending upon each individual’s specific situation, including symptoms, age, and ability to obtain long term care, the choice between DBS and pallidotomy should be considered. In tight economic situations, or situations where long term follow up is not easily available lesioning of the globus pallidus might be a reasonable and efficacious treatment for some people with PARKINSON’S DISEASE.
Written by Marcia McCall