Deep brain stimulation can aid Parkinson's sufferers

Deep brain stimulation can aid Parkinson's sufferers

Sending small pulses of electricity to the brain can relieve the symptoms of Parkinson's disease and other neurological conditions, writes David Tan

Monday, 08 July, 2013 [Updated: 9:35AM]

David Tan life@scmp.com

 

Wires inserted into the brain delivering jolts of electricity able to alter movement and behaviour may sound like the stuff of a sci-fi movie. But for people suffering from certain neurological conditions, this scenario is real and offers a much-needed source of relief.

Deep brain stimulation uses a surgically implanted medical device, similar to a pacemaker, to deliver mild electrical pulses to precisely targeted areas of the brain.

Over the past two decades, doctors have turned to deep brain stimulation (DBS) to help people with Parkinson's disease, and movement disorders like essential tremor and primary dystonia, a debilitating condition that causes painful, twisting muscle spasms.

It's already an established treatment for advanced stages of Parkinson's that medication alone can no longer treat. Although it's not a cure, and doesn't halt disease progression, for certain patients it can vastly improve symptoms such as tremors and muscle rigidity that could make the patient dependent on a caregiver.

But the therapy is no longer seen as a last resort. It's also being applied to earlier stages of Parkinson's. Scientists are also exploring other applications for the therapy: to treat obesity, Alzheimer's disease and psychiatric conditions such as depression and obsessive-compulsive disorder.

Chronic stimulation of sub-cortical structures was first used in the early 1950s, but the modern form of DBS, developed in 1987, can be attributed to Alim-Louis Benabid and Pierre Pollak of the University of Grenoble's department of neurosurgery and neurology in France.

The surgery evolved out of the surgeries in which doctors used heat probes to burn and permanently damage small regions of the brain that are known to trigger certain neurological conditions.

In DBS, instead of destroying tissue, a neurosurgeon implants slender millimetre-thick electrodes that pump steady electrical pulses via a battery-powered device - a "brain pacemaker" - that's implanted in the chest.

The device is programmed externally with a remote, hand-held controller to fine-tune the electrical stimulation for individual patients.

The US Food and Drug Administration approved the surgery for "essential tremor" in 1997 and for tremors associated with Parkinson's disease in 2002.

DBS was first introduced in Hong Kong in 2007 at the Prince of Wales Hospital. The first patient benefited from the treatment for more than 16 years and had to undergo battery changes only twice at six-year intervals, according to Professor Poon Wai-sang, chief of neurosurgery at Chinese University.

Benefits vary among patients according to the severity of their condition. "Our initial selection of patients was conservative - choosing the most disabled patients. [But] it turned out that the moderately disabled patients benefited most," Poon says.

A recent two-year clinical trial found it might improve overall quality of life and social functioning in patients in earlier stages of Parkinson's, too. In the past, doctors have relied solely on drugs in this period.

The study, published in February in the New England Journal of Medicine, showed that DBS was more effective than other medical treatment in patients with Parkinson's disease and early motor complications. The study's lead investigator, Dr Günther Deuschl, a professor of neurology at Christian-Albrechts-University in Kiel, Germany, says: "These results signal a shift in the way patients with Parkinson's disease can be treated."

In Singapore, about one or two cases of DBS are performed each month at the National Neuroscience Institute, according to Professor Ng Wai-hoe, head of the institute's neurosurgery department. "At present, we normally offer DBS to [Parkinson's] patients with moderate disease severity; that is, when patients begin to experience problems with their motor system or when they develop adverse effects from medication," Ng says.

DBS could rapidly become a treatment for people with obesity

Dr Casey Halpern

"The surgery takes two to three hours but can vary depending on the technique used by the functional neurosurgeon. At the National Neuroscience Institute, we make use of both anatomical targeting and microelectrode recording to place the electrode."

A new, safer way to perform the surgery, detailed in an article last month in the Journal of Neurosurgery, could expand significantly the number of patients who might be candidates for DBS surgery. Using advances in brain imaging, the new technique - tested in 60 patients - allows for extremely accurate electrode placement. Implanting them is painstaking: it starts with boring a hole through the skull and threading the electrodes deep into the brain, aiming for a spot that's a fraction of the size of a pea.

"Patients don't need to be awake during this surgery - which will mean many more patients who can be helped by this surgery will now be willing to consider it," says Dr Kim Burchiel, chair of neurological surgery at Oregon Health & Science University and lead author of the study.

Apart from Parkinson's, DBS is now also being tested for Alzheimer's, another form of dementia that also has no cure and is not easily managed.

Dr Douglas Scharre, from the Ohio State Wexner Medical Centre in the US, says the disease is progressively disabling, with loss of memory, cognition and worsening behavioural function.

His team enrols patients with mild or early-stage Alzheimer's to determine whether DBS treatment can improve brain function involved in cognition and behaviour.

DBS could also help people with conditions such as intractable depression, refractory epilepsy, obsessive compulsive disorders and drug addiction.

Addiction can take many forms, including binge eating and alcohol dependence - both of which are being targeted with DBS therapy. In mice and people who overeat compulsively, scientists have pinpointed an abnormality in the regulation of the brain's reward system. Through tests on obesity-prone mice, researchers at the University of Pennsylvania in the US reported in April that DBS reduces binge eating.

"Once replicated in human clinical trials, DBS could rapidly become a treatment for people with obesity due to the extensive groundwork already established in other disease areas," says study lead author Dr Casey Halpern.

For alcoholism, lab tests on rats have shown that DBS consistently reduced alcohol consumption in the rodents. Tests on human alcoholics show that DBS treatment produced less risky and more controlled behaviour accompanied by reduced drinking.

Intriguingly, while the effects of DBS are reportedly reversible, doctors have been surprised to find patients who continued to enjoy symptom relief even after their devices were switched off.

A recent study reported that two patients being treated for dystonia had their DBS devices accidentally switched off for months, but they only noticed it when mild symptoms returned.

Dr Michele Tagliati, director of the movement disorders programme at Cedars-Sinai Department of Neurology in the US, says: "Current thought is that symptoms will worsen within hours or days of device shut-off, but these two young men continued to have clinical benefit despite interruption of DBS therapy for several months.

"To our knowledge, these two cases represent the longest duration of retained benefit in primary generalised dystonia."

Moreover, when these patients' symptoms did return, the severity was far milder than it was before DBS, Tagliati says.

life@scmp.com

http://www.scmp.com/lifestyle/health/article/1276130/deep-brain-stimulation-can-aid-parkinsons-sufferers

Large study of deep brain stimulation underway for Alzheimer's disease treatment

Published on June 10, 2013 at 12:54 AM ·      

Together, Butler Hospital and Rhode Island Hospital are participating in The ADvance Study, a clinical trial investigating the use of deep brain stimulation (DBS) as a treatment for patients with Alzheimer's disease. The collaborative study between the two hospitals is part of a multisite clinical trial investigating the safety and efficacy of DBS in slowing the loss of memory and cognition in patients with Alzheimer's disease, a disease which currently afflicts more than 5 million people in the US and for which there is no cure.

A device currently used to treat other brain-related conditions, DBS is often described as a 'pacemaker for the brain,' as it uses an implanted device to electronically stimulate the brain. In the ADvance Study, a pacemaker-like device is implanted beneath the skin in the patient's chest to deliver electrical pulses directly to the fornix- a part of the brain that plays a central role in memory. DBS is currently FDA approved to treat Parkinson's disease, Tourette's syndrome and resistant Obsessive Compulsive Disorder.

"Alzheimer's researchers from around the world, including those at Butler and Rhode Island Hospital, are committed to developing safe and effective treatments for Alzheimer's disease," said Stephen Salloway, MD, principal investigator for the study and director of the Memory and Aging Program at Butler Hospital. "DBS has helped transform the treatment of Parkinson's disease and we hope that stimulation of memory circuits can have a similar benefit in treating Alzheimer's disease." Salloway notes that the approach in this study differs from medications and vaccines that are being investigated for Alzheimer's disease. DBS uses a device that has already been safety-checked and FDA approved for treating other conditions and has been shown to be safe in early studies with Alzheimer's patients.
This clinical trial stems from a preliminary DBS study in six patients with Alzheimer's disease in Canada. That study found that patients with mild forms of the disease showed sustained increases in glucose metabolism, an indicator of neuronal activity, over a 13-month period. Most patients with Alzheimer's disease show decreases in glucose metabolism over the same time period.

In the double-blind clinical trial being conducted at Butler and Rhode Island Hospital, all participants will have the device implanted. Half of the participants will have the device activated in the first year, and all participants will receive active stimulation in the second year of the study. Following an initial evaluation at Butler, participants will have the device implanted at Rhode Island Hospital under the direction of Garth Rees Cosgrove, MD, chief of neurosurgery at Rhode Island Hospital, Chairman of the Department of Neurosurgery at Warren Alpert Medical School of Brown University, and Director of the Norman Prince Neuroscience Institute at Rhode Island Hospital.

"The results of the preliminary trial are very encouraging," said Dr. Cosgrove. "We have seen tremendous success in using deep brain stimulation on many of our patients with other neurological illnesses such as Parkinson's disease, and it has truly been a life-changing treatment. If we can achieve a similar response with our Alzheimer's patients then we will have the opportunity to improve millions of lives."

After the device is implanted, participants will visit Butler to have the device programmed by Victoria Chang, MD, a neurologist with expertise in DBS programming. Researchers at Butler will monitor safety outcomes and changes in memory, cognition and daily functioning with brain scans performed at Rhode Island Hospital. "This study is an example of a true collaborative effort between our two hospitals and health care systems to make progress against a devastating illness," said Dr. Salloway.

Source: Lifespan

http://www.news-medical.net/news/20130610/Large-study-of-deep-brain-stimulation-underway-for-Alzheimers-disease-treatment.aspx

New technique for deep brain stimulation surgery proves accurate and safe

New technique for deep brain stimulation surgery proves accurate and safe

June 5th, 2013 in Neuroscience

The surgeon who more than two decades ago pioneered deep brain stimulation surgery in the United States to treat people with Parkinson's disease and other movement disorders has now developed a new way to perform the surgery—which allows for more accurate placement of the brain electrodes and likely is safer for patients.

The success and safety of the new surgical technique could have broad implications for deep brain stimulation, or DBS, surgery into the future, as it may increasingly be used to help with a wide range of medical issues beyond Parkinson's disease and familial tremors.

The new surgery also offers another distinct advantage: patients are asleep during the surgery, rather than being awake under local anesthesia to help surgeons determine placement of the electrodes as happens with the traditional DBS surgery.

A study detailing the new surgical technique is being published in the June 2013 edition of the Journal of Neurosurgery, and has been published online at the journal's website.

"I think this will be how DBS surgery will be done in most cases going forward," said Kim Burchiel, M.D., F.A.C.S., chair of neurological surgery at Oregon Health & Science University and the lead author of the Journal of Neurosurgery article. "This surgery allows for extremely accurate placement of the electrodes and it's safer. Plus patients don't need to be awake during this surgery—which will mean many more patients who can be helped by this surgery will now be willing to consider it."

DBS surgery was first developed in France in 1987. Burchiel was the first surgeon in North America to perform the surgery, as part of a Food and Drug Administration-approved clinical trial in 1991.

The FDA approved the surgery for "essential tremor" in 1997 and for tremors associated with Parkinson's disease in 2002. The surgery has been performed tens of thousands of times over the last decade or so in the United States, most often for familial tremor and Parkinson's disease. Burchiel and his team at OHSU have performed the surgery more than 750 times.

The surgery involves implanting very thin wire electrodes in the brain, connected to something like a pacemaker implanted in the chest. The system then stimulates the brain to often significantly reduce the tremors.

For most of the last two decades, the DBS patient was required to be awake during surgery, to allow surgeons to determine through monitoring the patient's symptoms and getting other conscious patient feedback whether the electrodes were placed in the right spots in the brain.

But the traditional form of the surgery had drawbacks. Many patients who might have benefitted weren't willing to undergo the sometimes 4 to 6 hour surgery while awake. There also is a small chance of hemorrhaging in the brain as the surgeon places or moves the electrodes to the right spot in the brain.

The new technique uses advances in brain imaging in recent years to place the electrodes more safely, and more accurately, than in traditional DBS surgery. The surgical team uses CT scanning during the surgery itself, along with an MRI of the patient's brain before the surgery, to precisely place the electrodes in the brain, while better ensuring no hemorrhaging or complications from the insertion of the electrode.

The Journal of Neurosurgery article reported on 60 patients who had the surgery at OHSU over an 18-month period beginning in early 2011.

"What our results say is that it's safe, that we had no hemorrhaging or complications at all—and the accuracy of the electrode placement is the best ever reported," Burchiel said.

Burchiel and his team have done another 140 or so surgeries with the new procedure since enrollment in the study ended. OHSU was the first center to pioneer the new DBS procedure, but other surgical teams across the U.S. are learning the technique at OHSU, and bringing it back to their own centers.
The positive results with the new DBS technique could have ramifications as medical researchers nationwide continue to explore possible new uses for DBS surgery. DBS surgery has shown promising results in clinical trials with some Alzheimer's patients, with some forms of depression and even with obesity.

If the early promising results for these conditions are confirmed, the number of people who might be candidates for DBS surgery could expand greatly, Burchiel said.

The length of the new surgery for the 60 patients involved in the study was slightly longer than traditional DBS surgery. But as Burchiel and his team have developed the new surgical technique, the new DBS surgeries are usually much shorter, often taking half the time of the more traditional approach. Given that, and that the electrodes are placed more accurately and the surgery is cheaper to perform, the new DBS surgery likely will be the technique most surgeons will use in coming years, Burchiel said.

DBS surgery often helps significantly reduce tremors in patients with familial tremor and tremors and other symptoms in Parkinson's disease. A parallel study is ongoing at OHSU to assess how symptoms of the patients have improved since their DBS surgery using this new method.

Provided by Oregon Health & Science University

"New technique for deep brain stimulation surgery proves accurate and safe." June 5th, 2013.

http://medicalxpress.com/news/2013-06-technique-deep-brain-surgery-accurate.html