Five Questions Brain surgeon Michael Schulder, MD, . |
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| Q | What do we really know about deep brain stimulating implants? |
In neurosurgery, if we waited until all the chemistry and biology were sorted out, we’d never do anything. As a specialty, it’s been around for 100 years and there may come a time in the future when the ideas behind some of the things we do will seem incredibly barbaric. In the 1950s, a couple of neurosurgeons found that they could relieve symptoms of Parkinson’s by making holes in the brain. But the beneficial effects would wear off in time. Then, in the 1990s, a French neurosurgeon had a lightbulb moment — before making a hole in someone’s brain, you stimulate the brain to make sure you are in the right spot and to avoid creating side effects. After doing this enough times, he thought, “Why don’t I just stimulate?” This led to the current industry of deep brain stimulation (DBS) for certain conditions — but no one knows for sure how it works. With DBS, an implanted device delivers a mild electrical impulse to a specific area of the brain. Does the electrical
stimulation augment brain signals or block them? Does it block abnormal tremors or activate other pathways that somehow extinguish the tremor?
| Q | Along with Parkinson’s disease, what other conditions can be helped by DBS? |
Essential tremor (a benign but disabling condition), arm tremor from multiple sclerosis, and possibly epilepsy. Researchers are also looking at Tourette’s syndrome, which inhabits a borderline area in medicine between neurology and psychiatry because it is often linked with obsessive compulsive disorder (OCD). In the future, DBS might even be considered for Alzheimer’s disease.
| Q | Why is brain surgery for mental illness controversial? |
Using neurosurgery for psychiatric problems like depression, schizophrenia, OCD, or anything that was once associated with the kind of psychosurgery we saw in movies like One Flew Over the Cuckoo’s Nest, is extremely controversial. But keep in mind that those psychosurgical techniques were developed at a time when there were no other treatments for very sick, sometimes violent, patients. Yes, there may have been abuses but the surgery was considered a great advance then because it freed many people from nasty mental institutions. It wasn’t until the 1950s that medications came along to control psychiatric symptoms. Then, in the 1980s, the wheel turned yet again when the beneficial long-term effects of some drug therapies turned out to be not foolproof, and the side effects of these medications became increasingly apparent. Psychologists and psychiatrists who are not biologically oriented are very much against the use of DBS for treating patients with psychiatric disorders because they see these mental difficulties as psychological, functional disorders not amenable to physical solutions. So in these cases — let’s say depression, which is debilitating and resistant to drugs — DBS has to be done with really great care and the lead should be taken by a psychiatrist, not a neurosurgeon.
| Q | What’s on the horizon for the science of brain implants? |
When you start talking about the interface between the brain and machine, you can see some amazing things in the future. There are two or three research groups in this country who are looking at ways to have the mind control physical space.
I organized a symposium at a neurosurgery meeting last year on this topic. Let’s say you want to generate virtual arm movement for someone who is severely paralyzed, someone prevented from moving, maybe even speaking. One method involves implanting tiny electrodes into the brain in the primary motor area that physically controls arm movement. The patient would simply be able to think: “Move right arm.” And, a cursor on a computer screen would move to the right. Over time, a person can learn to use the cursor to generate speech and do a variety of complicated tasks. Other methods are completely noninvasive and amplify brain signals that are detected on the scalp to accomplish the same thing. As this technology matures, it’s conceivable that someone who has had a stroke could use it to move a limb or walk. Obviously, we’re only at the infancy stage now, however, but the potential is awesome.
| Q | What’s the most important tool in your professional life? |
A telephone. This is what I always tell my residents who assume my answer is going to be an MRI or a computerized surgical navigation tool. As a neurosurgeon in training, but even after years in practice, you should never take too much upon yourself. When you are faced with a complicated problem, don’t hesitate to ask for advice or help if this will benefit your patient.