Motor Improvement in Patients with DBS Sustained for up to 10 years
In August, researchers from Toronto, Canada, published a paper in Archives of Neurology following up with Parkinson's disease (PD) patients who had undergone Deep Brain Stimulation (DBS) surgery 10 years earlier. The study found that motor improvement, on the whole, was sustained 10 years following the procedure, although overall benefit was less than patients had experienced in the immediate aftermath of the procedure.
The Michael J. Fox Foundation (MJFF) spoke with Scientific Advisory Board member, DBS pioneer, and study author Andres Lozano, MD, PhD, on the meaning of these results to people with PD, especially those who are considering DBS as a treatment option.
MJFF also spoke about the findings with two patients: Ian Pearson, of Toronto, Canada, who underwent DBS 10 years ago, and Anthony Farinella, of Monroe, New Jersey, who plans to begin the process next week.
(For a basic description of DBS surgery, please visit Parkinson's 101 on our Living with Parkinson's page.)
MJFF: Dr. Lozano, Let's begin with the basics. Why might an individual with PD opt to have DBS?
AL: For those who are disabled by the motor aspects of PD, DBS can be a highly effective and reasonably safe therapy, and based on our recent findings, the benefits can be expected to last over the long term. For the right candidates, DBS is one of our best options to help people with PD feel better and experience greater quality of life.
Still, in any conversation about DBS, it is important to remember that this procedure is a symptomatic treatment of PD, not a cure. While DBS provides an important symptomatic benefit, the patient's Parkinson's will continue to progress over time.
MJFF: Who are the right candidates for DBS?
AL: Patients who are experiencing difficulties with the drugs they are taking, and in particular with unpredictability of response as related to motor fluctuations throughout the day, are good candidates for DBS. They tend to continue to have a good response to levodopa, but with motor fluctuations.
The minimum goal of the surgery is to ensure that each individual's best response to therapy is maintained, and we've seen that the procedure is particularly good at smoothing out these peaks and valleys experienced by patients taking levodopa.
The procedure is performed at almost all major centers in the world, and 8,000 to 10,000 patients now undergo DBS each year.
MJFF: Tell us more about your new findings.
AL: We found that the motor symptoms associated with PD -- tremor, rigidity, and bradykinesia, or slowness of movement -- were improved after the procedure. Moreover, the benefit to these symptoms was sustained up to ten years.
However, we found that in some aspects, in particular posture and gait, the patients were worse. Non-motor symptoms, such as cognitive impairment, fatigue and digestion issues, unfortunately also continued along their natural course without much influence from the surgery.
MJFF: You were a pioneer in developing DBS to treat Parkinson's disease. How has the field changed in the past 10 years?
AL: It used to be that when you had PD, you could not move. In the past 45 years, we've developed levodopa and other drugs capable of manipulating dopamine production in the brain. Patients on these drugs could move and they seemed to be better off. But over time we also learned about the limitations of these drugs and realized we had a lot more work to do to meet patients' needs.
When DBS use for PD first started becoming more widespread about 20 years ago, it extended the period of good function in many patients for several years beyond the drugs' effective window. It may sound like the tail wagging the dog, but in my mind the surgery has actually provided a much broader knowledge of the disease itself. As we knocked some of the motor symptoms down to size, we started to realize the importance of other aspects of the illness, which used to be overshadowed by the movement aspects. We now realize we are dealing with a multi-system disorder. In this way, PD is a conceptually different illness from what it was 10 years ago.
MJFF: How do you expect DBS to be used moving forward?
AL: We are now moving forward with research into DBS treatments that might begin to treat non-motor symptoms of the disease. Traditionally, these symptoms are unresponsive to surgery. But there are different circuits in the brain, and each has its own unique job to do. Some are for tremor, some deal with rigidity, for example. Others regulate cognition and depression. We now believe that if we focus on specific circuits, we can isolate treatment for more specific symptoms. It's like if you took your car in to get repaired -- just because you need a new muffler doesn't mean you also need to fix the engine. And even if you did, you wouldn't expect the same procedure to fix both parts of the car.
We are now analyzing areas of the brain which are involved in generating non-motor symptoms. Traditionally, DBS targets the subthalamic nucleus. One of these new targets is the pedunculopontine nucleus (PPN), which could specifically address posture and balance, symptoms that traditionally do not respond to DBS. As of this conversation, 100 patients in the world have undergone this procedure, and many centers are investigating the safety and efficacy of stimulating these areas of the brain.
Additionally, there's reasonable evidence that the earlier you intervene with DBS with Parkinson's the more effective it can be. There is now interest in not paying the opportunity costs of being ill for so long and introducing DBS earlier in the course of the illness with the view of keeping people functioning at a higher level. We suspect that these benefits will be long lasting. We have data for 5 years and 10 years, but we suspect these benefits will continue over the long term.
Ian Pearson, of Toronto, Canada, underwent DBS 10 years ago. He says that his quality of life has significantly changed for the better since then.
MJFF: Ian, tell us about your experience with PD. How did you feel before and after DBS surgery, and how have things progressed up to today?
IP: It's going to be 11 years this coming May. I was 50 years old. I remember that, at that point in my life, the medication wasn't working anymore. I found that I would either freeze up completely, or I was moving around all over the place like a rag doll. I had no quality of life.
For me, medication had become the problem, and when I came to my decision to have DBS, I figured that things really couldn't get any worse.
Immediately after DBS, it was like night and day. I didn't take any medication at all for a year and a half following the procedure, and I felt tremendous. Slowly, I had to add medication back into my daily routine, but I still felt so much better than I had prior to DBS.
Ten years later, I can still do most things. My motor skills are still very good -- I can run up and down the stairs, or walk a couple of miles, even do an exercise routine. My speech is a little off, and my memory isn't so good, but DBS made me normal again.
I realize that my best days are probably in the past, but I am optimistic because the changes in how my PD is now progressing are very gradual. I still will have a good quality of life into the future. I feel very lucky.
Anthony Farinella began the month-long process of undergoing DBS on September 28.
MJFF: Anthony, why did you decide to undergo DBS, and what are your expectations?
AF: I'm 62 years old, and was diagnosed with PD 13 years ago. Since then, my quality has really deteriorated. This past April, I fell and hit my head on a wall, and ended up in the hospital. We've sold our house with stairs to move into a ranch since then.
I now take levodopa every three hours, and notice that very often, it takes an hour to kick in, I'm good for an hour, then I can't move. Bad time has increased and is more than good time for me. I'm pretty much homebound all the time, and can only walk very sporadically. I can't live with the fact that I can't walk.
When my doctor recommended DBS, I immediately thought that I'd like to be a candidate. I then went to see a neurologist and a neuropsychologist to verify that I was indeed qualified.
Honestly, I'm afraid of having the surgery. I have to have four surgical procedures in the course of a month. But my quality of life is so bad now. I am a burden to my wife. I need help going into the shower. I need help putting on my clothes.
But I am positive about how this surgery will turn out. My goal is to go to Disneyworld after the procedure. I'm hopeful that I will be able to make my own breakfast or even play tennis or basketball. Mostly, I look forward to being independent again. To bringing back some quality of life.
NOTE: The medical information contained in this article is for general information purposes only. The Michael J. Fox Foundation has a policy of refraining from advocating, endorsing or promoting any drug therapy, course of treatment, or specific company or institution. It is crucial that care and treatment decisions related to Parkinson's disease and any other medical condition be made in consultation with a physician or other qualified medical professional. Every patient is different, and responses to treatments like DBS may vary.