William J. Weiner, MD
William J. Weiner, MD, professor and chairman, department of neurology, University of Maryland School of Medicine, Baltimore.
Parkinson’s Disease (PD) has been in the news of late, and not only because actor and PD patient Michael J. Fox has given it a high profile. On several research fronts, there’s exciting news. For people who have the debilitating disease, none of this can happen quickly enough.
Devastating for the million or so Americans suffering from PD is the fact that not only is there no cure but medication is only somewhat effective — true even of the one most commonly used, levodopa/carbidopa (brand name Sinemet). Finding the right drug often involves trial and error and these drugs have numerous side effects including digestive distress, headaches, fatigue and — ironically, even more uncontrollable movement.
The frustration on the part of patients and doctors alike has been replaced by cautious optimism in recent months, thanks to a gene therapy experiment involving just 12 patients at Weill Cornell Medical College in New York City. Doctors injected copies of a synthesized gene associated with production of a chemical GABA, deficient in PD patients. The hope is that increasing GABA levels might help calm the overactive brain circuitry that triggers some PD symptoms — and indeed within three months of the gene insertion procedure, patients’ symptoms, especially tremors, stiffness and walking problems, began to improve, and the benefit remained at least stable throughout the one-year study.
For insight on this and other recent PD research, I called neurologist William Weiner, MD, director of the Maryland Parkinson’s Disease and Movement Disorder Center at the University of Maryland School of Medicine in Baltimore. While acknowledging these gene therapy study results are encouraging, Dr. Weiner stresses that this new and innovative research is preliminary, noting that caution is warranted since there’s a long history of research on PD with lots of promising developments and discoveries that went nowhere. Dr. Weiner adds that even though study patients showed continuous symptom improvement, there’s not yet actual proof that the gene therapy caused a specific biological change. Certainly it’s an exciting development, but the possibility that it will turn into a treatment option for PD patients is still, unfortunately, a long way off, he says.
Researchers are also studying two other areas — the first is a possible association of PD with narcolepsy, a disorder that causes sudden onset of daytime sleep and nighttime sleeplessness. By examining human cadaver brains, a UCLA and Veterans Affairs Department research team discovered that PD patients lack sufficient quantities of a brain peptide called hypocretin. This was of great interest because the same group had previously identified lack of hypocretin as the cause of narcolepsy. Dr. Weiner’s take on the study: Although sleep problems — including insomnia, frequent sleep waking and REM sleep disorder — are common among people with PD, this research, too, is in an early stage.
Finally, there is new research on the use of Co-enzyme Q10 (commonly called CoQ10), a powerful antioxidant. Dr. Weiner says that the Parkinson’s Disease patient community has been enthusiastic about CoQ10, based on the rumor that it slows disease progression — but in reality, the research has been equivocal. A large National Institutes of Health (NIH) study investigated the effects of 1,200 mg of CoQ10 a day for PD patients: Its stated conclusion was that CoQ10 might slow functional decline. Another study, based on double that amount, will soon be undertaken by NIH to investigate how 2,400 mg/day of the antioxidant affects symptoms. Until we have those results, which could take years, Dr. Weiner is unwilling to advise patients to take CoQ10, feeling that there’s not yet sufficient proof to warrant its substantial monthly cost ($150 to $300), which insurance does not cover — not to mention the little, if any, research on how it affects people with Parkinson’s, most particularly in mega-doses.
Dr. Weiner did tell me about one other new technique that he believes holds promise, though not many people are using it — deep brain stimulation (DBS). This involves surgically implanting a battery-operated device in the brain that is then manipulated to alter brain activity through low-voltage stimulation. It has proved to be very helpful, especially for patients with advanced PD whose medications have started to falter. It can prolong the length of time PD drugs are effective and enable patients to take smaller dosages, which results in fewer drug side effects. Dr. Weiner is surprised that not many PD patients have taken advantage of DBS, which he attributes in part to a lack of awareness. It’s also possible, and understandable, that they find the prospect of such an invasive procedure frightening. He noted that there are some risks: DBS is associated with a small risk of bleeding-induced stroke (approximately 1% to 3%), infection and breakage or malfunction of the equipment. For those who are interested in DBS, it is crucial to seek out a Parkinson’s Disease center or major teaching hospital where there is a fully trained team experienced in all aspects of DBS care. For more information, go to www.parkinsons.org or www.apdaparkinsons.org.
As to the future, Dr. Weiner reports that there is much hope for new developments with many trials currently in progress. Scientists continue to be baffled by what causes PD, but Dr. Weiner says that current thinking now focuses on certain genes that combine in strange ways or interact with as yet unknown environmental factors. Understanding what causes PD can lead to earlier intervention and perhaps one day even prevention. Though he doesn’t think the problem will get solved soon, Dr. Weiner says he believes this is the most promising direction thus far. In the meantime, he cautions PD patients to be careful about headlines that promise too much, but at the same time to pay close attention to research news because real progress will definitely come.