In this full-length doctor's interview, Dennis Bourdette, M.D., explains how the use of Ginkgo may improve the cognitive disabilities suffered by many multiple sclerosis patients
March 15, 2004
Transcript with Dennis Bourdette, M.D., Neurologist, Oregon Health & Science University, Portland, Oregon
Ivanhoe Broadcast News
What prompted you to start this study with Ginkgo and multiple sclerosis patients?
Dr. Bourdette: The number one reason was we have no treatments for cognitive impairment in multiple sclerosis. This is a major problem for people with MS, and we were interested in trying anything that offered a reasonable hope of providing benefit. There is evidence that Ginkgo can help a modest degree of people who are suffering from Alzheimer's disease. The memory problems of MS are different from those with Alzheimer's, but we reason that if it benefits Alzheimer's patients, it may also benefit MS patients with cognitive difficulties.
Wasn't there also a smaller study with MS patients and Ginkgo that produced good results?
Dr. Bourdette: There was a smaller trial that came out of the University of California, San Diego, in people with MS suggesting Ginkgo would provide some benefit. This gave us added encouragement to proceed with designing this larger trial.
Do you know what the results were of the earlier study? How many patients were in that study, and how well were their cognitive abilities improved?
Dr. Bourdette: There were approximately 20 people with MS that were enrolled, and they noted about a 15-percent improvement when the patients were on Ginkgo.
What does improvement entail? Does that mean that they have better memories, or that they're better at completing tasks?
Dr. Bourdette: What we're hoping to see is improvement in the areas where people with MS commonly have difficulties. These areas are problems with their short-term memory, problems doing multiple tasks at once, and problems with attention and concentration. These are the source of problems that patients encounter with their day-to-day lives. We have objective psychological testing that can measure these different functions. We hope to see an improvement in functions of patients that are taking Ginkgo compared to those taking placebo.
Most people think of MS patients as people who have trouble walking, or someone who might be in a wheelchair. How many of these MS patients are actually affected with these cognitive difficulties?
Dr. Bourdette: Sixty percent of people with MS develop significant cognitive problems. This is often one of the more troubling symptoms. It is the number one reason that these people are unable to be employed. We'll see people, for instance, who have terrible MS affecting just their spinal cord. They are paralyzed and in a wheelchair, but it hasn't affected their brain, and so they have normal cognitive functions. Those people are very often employed and have no major disruption in their social activities. We see others that have a lot of MS affecting their brain but not their spinal cord. They walk normally, but they have significant cognitive difficulties. These people are actually more disabled in that they can't work, and there is disruption in their family and social life. It's a major problem, and neurologists just recently recognized this as a significant problem.
So it doesn't necessarily follow that if you have MS you are eventually going to have cognitive difficulties?
Dr. Bourdette: Absolutely. The best predictor of cognitive impairment in MS is how much of the brain is involved with MS. This prediction is based upon looking at an magnetic resonance imaging scan of the brain. It allows us to visualize the brain and helps assess how much damage MS has caused.
What is actually happening to the brain? What is MS doing to the brain to affect those cognitive abilities?
Dr. Bourdette: The brain and the spinal cord operate by neurons interacting with one another, and they do so by sending electrical wires between each other. The electrical wires are coated with an insulating-type material called myelin. The myelin has electrical wires themselves, which become damaged in bits in the spinal cord. It is that destruction that leads to disability. And we are actually able to visualize these spots in the brain where this destruction has occurred.
Seems like the patient is having the myelin and nerve impulses eaten away so that there's no connection?
Dr. Bourdette: It's like a very complex electrical system; if the electrical wires are being destroyed this can block electrical impulses going down the electrical wire. The electrical wires themselves can be severed, which, of course, permanently blocks the ability to conduct electricity.
Have you seen any preliminary results from this where patients were actually experiencing better cognitive abilities because of taking the Ginkgo?
Dr. Bourdette: This study is a double-blind placebo-controlled trial. Half the patients are given placebo, and the other half is given Ginkgo. All of us that are evaluating the patients are blind as to which patients received what. So we really don't know at this point. I have had some patients with cognitive difficulties, outside of this study, take Ginkgo and report that its provided them benefit. But we really need to complete this study to determine whether or not that's true.
What is it in the Ginkgo that is supposedly improving cognitive ability? And how did someone figure out that you could take these leaves from a Ginkgo tree and help improve your mind?
Dr. Bourdette: Ginkgo has been used for about 1,000 years to improve cognitive performance. There are ancient medical reports of that. It has been used in a number of trials in Alzheimer's disease, particularly in Europe, suggesting benefit. Ginkgo's composed of a large number of different chemicals, and it's not really clear which of those chemicals is the active agent. One big class of those agents, however, is antioxidants. Oxidative injury is important in MS and some of the products that cause oxidative injury can also interrupt electrical activity among the nerves. It's quite possible that the Ginkgo works by dampening down and blocking these chemicals that are interfering with the electrical transmission, and therefore improves electrical transmission and performance.
How long is this study?
Dr. Bourdette: We should have results within a year. If this was a drug and we were doing an FDA- approved trial, then this would be classified as a phase two trial. If we get positive results we'll seek funding to do a much larger multi-center trial to firmly establish that its effective.
How many patients are in the trial?
Dr. Bourdette: There are 60 patients -- 30 patients taking Ginkgo, and 30 patients taking placebo. They are on treatment for three months, and we are studying them for four months. The patients get tested on their cognitive functions on three separate occasions.
Are there any harmful effects of Ginkgo?
Dr. Bourdette: In general no. The one concern or potential side effect is that another set of the chemicals in the Ginkgo leaf interferes with platelet function. Platelets are involved in blood clotting. So there have been reports in a few elderly patients taking Ginkgo of bleeding problems in the brain. That has not been demonstrated in younger individuals. Thus far, we have not seen any evidence of side effects in our study, or evidence of platelet dysfunction.
Some MS patients who hear this might go out and get Ginkgo. Is that something that you would suggest at this point considering it's not regulated? Is it something that is worth a try?
Dr. Bourdette: At this point we really don't have good data to be advocating the use of Ginkgo.
When your patients come in and they're not on the study, do you tell them that the use of Ginkgo is something that's worth a try or do you dissuade them? What is your advice to your own patients?
Dr. Bourdette: We've done a survey here in Oregon, which indicates 20 percent to 25 percent of Oregonians with MS are taking Ginkgo, with or without their physicians recommending it. If I were asked about trying it, I would tell my patients it is safe. I don't have any objection as a physician to anyone trying it. But I would also tell them that it is still being studied.
You stated that there is nothing on the market for the improvement of cognitive abilities in MS patients, so are you encouraged that this might be something? Is there any evidence you have right now that you could say this is encouraging news?
Dr. Bourdette: The only evidence I have are a few of my patients who've taken Ginkgo on their own and have said it helped them. We have the small trial from UC San Diego suggesting some benefit. In terms of our own scientific data, we won't know until we've analyzed it. To show that those individuals taking Ginkgo were doing better than those on placebo will take another year.
How many patients in the United States have MS?
Dr. Bourdette: Three hundred thousand to 500,000 patients.
What are the other symptoms that you might see in an MS patient besides the cognitive disabilities?
Dr. Bourdette: These patients can lose vision in one or both eyes; they can have problems with double vision, problems walking due to poor balance or leg weakness, and problems with bladder control, or use of their hands.
What led you to the point that you wanted to invest so much time and energy in this study?
Dr. Bourdette: This is an important problem and we have nothing
to offer patients with MS that are suffering from cognitive impairment
to help improve their performance. It's very important that we pursue any
avenue for which there is a reason to believe that it might be beneficial.
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc., or any medical professional interviewed. Ivanhoe Broadcast News, Inc., assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
If you would like more information, please contact:
The Multiple Sclerosis Center of Oregon
Oregon Health & Science University
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