PITTSBURGH (Ivanhoe Newswire) – Deep brain stimulation for Parkinson’s disease has been a successful treatment option for more than a decade, but only for some patients. Now a new technique is changing the game and helping thousands of more people get the treatment they so desperately need.
Toni Pais is 59 years old. He’s a hands-on restaurant owner who is often prepping for the dinner crowd by himself. However, tremors from Parkinson’s disease almost forced him to quit.
“It’s very dangerous because you are dealing with fire with hot pans, sometimes you try to shake the pan, your brain wants to move, but your muscles don’t,” Pais told Ivanhoe.
Medication was losing its affect. Pais couldn’t tolerate the traditional surgical method for implantation of deep brain stimulators, which would require him to be awake during surgery.
During DBS, surgeons implant thin electrodes at very specific targets in the brain to deliver electrical pulses. Doctors interact with the patient to ensure the electrodes are in the correct place.
“The problem is, there is a significant population of patients with Parkinson’s who are too anxious, or too symptomatic, or both to undergo awake surgery in the frame,” Mark Richardson, MD, PhD, Director of Epilepsy and Movement Disorders Surgery, UPMC, told Ivanhoe.
Now surgeons have begun performing the procedure on patients who stay “under” the whole time using customized software and an MRI machine. Surgeons attach an aiming device to the skull and the surgeon maps the trajectory of the electrode in real time.
More than one year after surgery, Pais says his tremors are minimal, so are his other symptoms.
“Now if I’m relaxing, sleeping, lying down, [or] contemplating, I’m calm as calm can be,” Pais explained.
UPMC researchers say a preliminary analysis of patient outcomes shows there is no difference in side effects or benefits for patients who undergo the procedure asleep.
BACKGROUND: Parkinson’s disease is a condition of the brain affecting approximately six million people. It is most commonly characterized by slowness of movement, stiffness, shaking, and loss of balance. Parkinson’s often develops after the age of 50. Although Parkinson’s disease is one of the most common nervous system disorders for the elderly, it can affect young people too, usually because a form of the disease runs in their family. Nerve cells use a brain chemical called dopamine to control muscles. When the nerve cells in the brain that produce dopamine are destroyed as a result of Parkinson’s, the nerve cells in that particular part of the brain will not properly send messages. The result is the loss of muscle control. The damage gets worse over time. (Source: www.ncbi.nlm.nih.gov)
SIGNS/SYMPTOMS: The first symptoms of Parkinson’s disease can be hard to diagnose, especially in older patients, and often start out mild and worsen over time. The most common signs of Parkinson’s disease are shaking, called tremors, and jerky, stiff movements. Some of the other possible signs include:
• Depression, anxiety, and memory loss
• Slowed movements, slow blinking, and slowed speech
• Difficulty swallowing and drooling
• Problems with balance and walking (www.mayoclinic.org)
NEW TECHNOLOGY: Deep brain stimulation is a technique that has been used for years now to treat conditions like Parkinson’s, dystonia, and essential tremor. The procedure to put the electrode in place usually takes place with the patient awake, because brain mapping is easier when the patient isn’t under anesthesia and so doctors can periodically check with the patient. However, now doctors can use MRI to place the electrodes needed for the neurostimulator. This means the patients can be put under general anesthesia for the surgery. The MRI helps doctors visualize in real time where the electrode needs to be placed. This is important for patients who are nervous, can’t tolerate being awake, or too dystonic to be still during a surgery. (Source: www.upmc.org)
Mark Richardson, MD, PhD, Director of Epilepsy and Movement Disorders, UPMC, talks about a new procedure for people with Parkinson’s.
Can you explain a little bit about what deep brain stimulation is?
Dr. Richardson: Deep brain stimulation is a neurosurgical technique where very thin electrodes are implanted in the brain at specific targets and electrical stimulation is delivered through a battery pack, or pulse generator, that’s implanted in the chest. And this is connected to the wire that goes into the brain and essentially the device acts like a pacemaker, and the way we think it works is to reset abnormal brain activity.
Are there any side effects to the DBS?
Dr. Richardson: There can be side effects from deep brain stimulation. The worst complication that could happen from surgery is a stroke.
What are some of the risks of DBS surgery?
Dr. Richardson: The main risk is stroke. There’s about a half percent chance per side of having a permanent deficit from a stroke. So the risks are very low but they are not nonexistent. There’s a greater risk of infection because it’s an implanted foreign object that’s in the body so there’s about a 5% risk of infection. There are some smaller risks for changes in mood or cognitive function but we screen for patients that are at high risk to develop those problems with neuropsychological testing before the operation. And then there can be side effects related to movement and sensation, which is why we have the patients awake if we use the traditional frame base method. We don’t expect to get these side effects if we use the MRI method because we can see the target in real time on the MRI.
Is medication usually the first line of defense when you have Parkinson’s?
Dr. Richardson: When someone is diagnosed with Parkinson’s disease medication is obviously the first treatment. For a lot of patient’s medication will work well for a long time, let’s say even 10 years before they start to develop unwanted side effects or before the medication can no longer keep up with the progression of the disease. But other people might have more severe form of the disease or one that progresses faster and they may be candidates for deep brain stimulation even sooner, as soon as a few years after their diagnosis. So in order to be a candidate for deep brain stimulation patients have to meet several criteria. It’s very important that there’s no question about the diagnosis of Parkinson’s disease because the brain stimulation does not treat other disorders well that might mimic Parkinson’s disease but are not truly Parkinson’s. Patients who are good candidates for deep brain stimulation are usually have been good responders to dopaminergic medicine the most common one being Sinemet. And these patients usually will have responded quite well for some time but then will have problems with unwanted side effects such as unwanted movements called dyskinesias or with increasing wearing off. So the amount of time where they feel like the medication is working over the course of the day shortens and the amount of time where they feel like they’re off medication really lengthens and that tends to be a real roller coaster ride for some of these patients.
Can you tell me a little bit about the surgery?
Dr. Richardson: The traditional way that deep brain stimulating electrodes have been implanted for over the past 15 years is a frame based surgery where the patient is the operating room fixed in a stereotactic head frame. So the location of their head and their brain remains stable for the length of the procedure. And there’s a targeting arc that’s then fixed to that frame and computer software that allows us to select a target on a preoperative MRI and plan a safe trajectory through the brain to place the electrode in the desired target. Patients are sleep for the start of this procedure when an incision is made in the scalp. A small opening in the skull is made. The covering of the brain, the dura, is then opened so that we can see a safe entry point. Then the patient is awoken and the electrodes inserted, first a recording electrode to do the brain mapping portion of the operation, to confirm that the trajectory is correct for reaching the desired target. And then when we have enough evidence that we are in the right spot from our brain recordings, we insert the stimulating electrode which is the actual DBS electrode. That’s turned on and we look for side effects to make sure that we don’t have too low of a threshold for producing unwanted changes in movement or sensation. And then we also look for benefit of stimulation as well.
How are you able to do the asleep procedure?
Dr. Richardson: The asleep procedure is able to circumvent the necessity to have the patient awake because it’s done in an MRI scanner. So we literally go into an MRI room, set the patient up in the scanner and turn that room into an operating room. So we make a sterile field, we image the patient and then there’s software that allows us to choose the target on the MRI in real time. Then we attach a customized mounting device to the skull that’s seen by the software and allows us to direct the trajectory of that device so that we can deliver the electrode to the target that’s chosen on the MRI. And we repeat the MRI several times during the procedure as we’re doing the alignment and then the opening of the covering of the brain. And this allows us to take into account brain shift, since sometimes when the covering of the brain is open the brain will shift a little bit. For DBS surgery we’re very concerned about changes in distances of a millimeter or two. These can be critical. So we really want that error to be on the order of no more than a millimeter. And the interventional MRI technique allows us to achieve that and allows us to verify that were within that millimeter of the chosen target in real time.
Is this as effective as doing it awake?
Dr. Richardson: This interventional MRI method was just FDA approved in the summer of 2010. But there is some early data, there’s data from the group that originated the procedure, which is six months outcome data that does show that stimulation from DBS electrodes placed in the MRI is just as efficacious as when they are placed in the frame. It looks like the accuracy of actual electrode placement in relation to the intended target is better in the MRI, we’re talking about literally maybe a 1 millimeter difference but certainly it’s not worse. And our own data which we’ve just analyzed, our first cohort of patients, suggests that also there’s no difference in terms of benefit or side effects for the patients who are implanted in the MRI versus the traditional micro electro guided approach.
Is there another medical reason where it would be beneficial for the patient to be asleep the whole time?
Dr. Richardson: Yes, there are medical reasons why it might be better to have the patient asleep. Those include tremor that’s so severe, especially when patients are off medication, which is the preferred state for doing awake surgery, that it would number one, be so uncomfortable for them but two, could potentially compromise the procedure because literally the head is shaking while we operate. There are other patients that can become so uncomfortable in the off state as their medication wears off that they can’t participate in the awake surgery as well which defeats the purpose of being awake in the first place. Certainly we have had some of those patients too for whom we have recommended the MRI procedure. There are Parkinson’s patients who come into clinic confined in a wheelchair because their mobility is so bad. So this is a red flag for a patient who on the one hand stands to potentially benefit a lot from deep brain stimulation and on the other hand is probably not the best candidate for being awake in the operating room. That’s the type of patient, even though in some cases they’re sicker in terms of their disease that we’ve steered towards the MRI procedure with very nice results.
The implant is permanent; this is not something that you take out?
Dr. Richardson: The implant is permanent; the battery is replaced every 2 to 5 years approximately. Now that’s a very easy surgery, it’s a same-day surgery and just so you know the surgery to implant the DBS electrodes just usually requires an overnight stay in the hospital. Patients tend to go home the next day.
Is there anything I didn’t ask you that you think people need to know?
Dr. Richardson: One thing a lot of people don’t know including physicians in the community is that DBS now is the proven gold standard treatment for medically refractory Parkinson’s disease assuming patients meet the other necessary criteria. So a lot of people don’t know that. This really is a therapy that’s been proven now in multiple clinical trials to provide much greater improvement and quality of life for these patients compared to just continuing medical management alone with relatively low risk for morbidity related to surgery.