Treating Parkinson's disease medically, surgically—and optimistically.
The earliest signs of Parkinson's disease sneak up almost imperceptibly. There may be a slight tremor, or perhaps a change in handwriting, a shift in personality, or a loss of the sense of smell. But as the brain produces less dopamine, an important chemical that contributes to mood and movement, and as healthy brain cells die, the disease progresses and the symptoms more typically associated with Parkinson's disease—pronounced tremors, shuffling steps, an unsteady gait, stiffness, and slowness—can become debilitating.
Many patients respond well to levodopa and other medications, which help to manage the symptoms of Parkinson's disease. "Medication may not be sufficient for everybody, though," says neurologist Roger Kurlan, MD, Medical Director of the Movement Disorders Program at Overlook Medical Center. When medication has failed due to an intolerance to side effects or is no longer effective ("It gets to be hard to find the right dosage after a while," he says), certain patients are candidates for deep brain stimulation (DBS), a surgical intervention that uses a pacemaker-like device implanted in the chest to control the electrical impulses of electrodes implanted in the brain.
Managing Parkinson's disease with DBS requires a cross-disciplinary approach between neurologists and neurosurgeons. It is the neurologist who must determine whether it is time to consider DBS, and in doing so must exclude those who are unlikely to respond well to surgery. "People who have responded well to medication seem to be better candidates for surgery," says Kurlan. Conditions such as depression or anxiety tend to impede the success of DBS, and for that reason, many patients with more than mild mood problems are not candidates for
If a patient is determined to be a candidate for DBS, he or she is referred to one of Atlantic Neuroscience Institute's neurosurgeons, who conducts an additional evaluation. Edward Zampella, MD, FACS, of Atlantic NeuroSurgical Specialists, one of the two neurosurgeons associated with the program, explains that DBS is used not only for Parkinson's but also for dystonia (a neurological movement disorder in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures), essential tremor (a nervous-system disorder that causes rhythmic shaking, usually in the hands), or tremor due to multiple sclerosis.
In preparation for DBS, the patient's brain is imaged with MRI and CT scans, and those images are fused together by a computer to generate reference points to be used to guide the placement of electrodes in the brain. During this part of the surgery, the neurologist and neurosurgeon work in tandem to ensure that the electrodes are placed properly, listening to nerve cells as they fire. "It sounds like static, or like snap-crackle-pop," Zampella reports. "We can assess different subsets of the nervous system by listening and visualizing with a scope." During the third stage of DBS surgery a week or so later, a pacemaker-like pulse generator is implanted in the chest, usually just behind the collarbone; it is this generator that sends the electrodes electrical stimulation that can be tailored to the needs of each patient.
Zampella points out that the original treatment for Parkinson's disease was surgery, though those original procedures destroyed brain tissue and created irreversible results. "It was only with the development of medication that surgery for Parkinson's disease fell by the wayside," he reports. "We found out over time that medications themselves were not without risk and didn't work for every patient, and 15 years ago the pendulum began to swing back to surgery. With DBS, we're not destroying any part of the brain—we're augmenting the signals in the brain." He acknowledges that DBS may sound risky, but says the procedure "is not so risky that patients should be afraid of the risk—there is usually long-term responsiveness."
Following the completion of the final stage of surgery, patients return to their neurologist two weeks later to start programing the stimulator. "Patients almost immediately feel better due to changes in their brain from having the electrodes in," reports movement disorders specialist Marcie Rabin, MD. "Then the stimulator takes over, and we can ease symptoms that way. We can stimulate different contacts or increase or decrease the intensity of the stimulation, and we often can decrease medication. It usually takes a number of programming sessions to produce the best results. It's an art and a science."
In fact, she explains that neurologists constantly adjust the parameters of the stimulators (there are more than 4,000 possible adjustments) as each patient's individual needs change over time. The fine-tuning is well worth it: "The results we see can be truly amazing," Rabin says. "We're giving patients back their quality of life."
Kurlan adds, too, that as an added benefit to DBS, there is evidence to suggest that the surgery may help to stave off the death of healthy brain cells: "The thinking is that when we normalize some circuitry in the brain, the damaged circuitry doesn't have to work as hard. The healthy cells may live longer."
For 84-year-old Michael Frascella, DBS surgery nearly a year ago certainly has helped to restore quality of life. He had been diagnosed with essential tremor 30 years ago. The tremor in his right hand had had been quite severe for years, and when he started having similar problems in his left hand, he knew he had to do something.
"It was difficult for me to function," he says. "I had difficulty eating. I couldn't hold a glass of water. I couldn't write—forget it." For a man as busy as Frascella, who spends his days working around the house and volunteering his time to organizations that assist people with physical, intellectual, and developmental disabilities, the limitations were especially frustrating.
He met with Kurlan, who, having ruled out other treatments, asked if Frascella had ever thought about having surgery for his condition. "I had never even heard of it," Frascella admits, "but Dr. Kurlan told me that even at my age, I was probably a candidate." A surgical consultation with Zampella confirmed that Frascella was indeed a candidate for DBS surgery. Though admittedly skeptical, Frascella didn't hesitate to schedule the surgery.
It was, without question, a success. "My right hand is as steady as can be," says Frascella. "I can eat without worrying about spilling all over the place. I can do all the things I want to do. It's changed my life."
The Movement Disorders Program at Atlantic Neuroscience Institute is a multidisciplinary program specializing in the diagnosis and treatment of such conditions as Parkinson's disease, essential tremor, dystonia, Tourette's syndrome, and restless leg syndrome. For more information or to schedule an appointment, call (908) 522-6144.