Study: Parkinson's breakthrough discovery

The implantation of deep brain stimulation (DBS) devices at an early stage of Parkinson’s disease – rather than at an advanced one – has been shown, in a breakthrough study published Thursday, to significantly reduce the tremors and other symptoms of the widespread neurodegenerative disease that begins mostly from age 60. The study, which appears in the prestigious New England Journal of Medicine, is likely to end the global practice up to now of implanting an electrical stimulating device only as a last resort, when medications are no longer effective.

The use of DBS devices, implanted under the thalamus in the brain, for Parkinson’s began in 1993 and was approved by the US Food and Drug Administration in 2001.

In 2005 the procedure was included in Israel’s basket of health services covered by the health funds, according to Dr.

Zvi Israel, a senior lecturer in neurosurgery at Hadassah University Medical Center in Jerusalem’s Ein Kerem.

Israel, who is director of its center for functional and restorative neurosurgery, is a leading Israeli physician who implants DBS devices into Parkinson’s patients.

“DBS has until now been reserved for those patients with fairly advanced disease, who have already developed complications of medical therapy. DBS turns the clock back on the disease for these patients by many years.

Sometimes the effects are very dramatic. Most patients enjoy a much better quality of life, often regaining independence and reducing their medication by an average of 50 percent,” he told The Jerusalem Post, in commenting on the new study.

“Despite the demonstration that DBS is a better option than best medical therapy for these patients, there has been a certain reluctance to send them for invasive therapy for many reasons, not all of which were in the patients’ best interests. Among others, potential complications of surgery would be stressed,” Israel continued.

The Hadassah neurosurgeon said that “occasionally, we would see a younger patient referred for surgery who could not tolerate medication, and these patients would do remarkably well.

There has been a trend, certainly in the experienced centers, to offer surgery at an earlier stage of disease. This is based on the premise that the risks of surgery are low, and that we have a responsibility to provide a better quality of life for our patients as soon as possible. This has not been an easy sell, because it involves something of a paradigm shift in the way that Parkinson’s has been managed for so many years.”

Thus, publication of the journal article is very important, as “reputable neurologists [at Christian-Albrechts University in Kiel, Germany] have compared early DBS to best medical therapy and have shown it to be significantly better for motor outcome and for multiple measures of quality of life,” Israel said.

There is no cure for Parkinson’s, which is a progressive, fatal disease that affects breathing, balance, movement and heart function and is one of the most common nervous system disorders of the elderly. Estimates in the US alone are from 500,000 to 1 million cases, while there are tens of thousands in Israel. Some cases, however, begin as early as age 40.

The disease is caused by the slow deterioration of the nerve cells in the brain that create the neurotransmitter dopamine, which helps control muscle movement throughout the body. When dopamine supplies decline, tremors and other symptoms begin, but after a few years of dopamine-replacement therapy, it loses its effect. Azilect (rasagiline), a drug developed at the Technion-Israel Institute of Technology and produced by the Israeli company Teva Neuroscience, has been found to relieve symptoms, but only in the short-term.

The German researchers, in a two-year trial, randomly assigned 251 patients with an average age of 52 who had the disease for an average of seven-and-a-half years to undergo the implantation of a DBS plus medical therapy or medical therapy alone. They concluded that neurostimulation was superior to medical therapy alone at a relatively early stage of Parkinson, before the appearance of severe disabling motor complications.

The leading producer of DBS equipment for Parkinson’s is Medtronic, based in Minnesota and the world’s largest medical technology company, with branches in 120 countries, including Israel. It is sure, on the basis of the new study, to apply for addition to Israel’s health basket