Until seven years ago, Robert Ducharme had "not a worry in the world," enjoying an active life and successful civil service career. Then, at age 48, a doctor diagnosed Parkinson's disease, and the degenerative illness advanced with frightening speed.
The Ottawa resident was soon all but helpless, the disorder's characteristic tremors leaving him unable to feed himself, dress or walk any distance. Two years ago, however, surgeons implanted a tiny electrode in the part of his brain that controls movement, connected it by leads to a battery pack installed near his collarbone, and switched on the electricity. Almost instantaneously, the debilitating tremors were gone.
"This has changed my life completely," said Mr. Ducharme yesterday. "This surgery, it's just an amazing, amazing thing."
About 75,000 Parkinson's patients and others worldwide have undergone the same deep-brain stimulation (DBS) procedure, the electrical current bringing about sometimes miraculous improvements.
But as it is applied experimentally to a wider and wider range of patients -- from severely depressed people to Alzheimer's sufferers and even the morbidly obese -- questions are being raised about the technology's growing allure.
Ethicists say patients, often carried away by glowing reports of the procedure's successes, need to be carefully briefed on DBS's unusual side effects, which have included mania, personality changes, marital discord and increased rates of suicide.
There is also concern about how that little electrode is sometimes changing patients' personalities, and worry about the less scrupulous applications that might come down the road. In an eery embodiment of the 2004 sci-fimovie Eternal Sunshine of the Spotless Mind, doctors will likely be able to erase people's painful memories through DBS within 10 to 20 years, said Dr. Mark Bernstein, a University of Toronto neurosurgeon and ethicist.
Already, he has been asked to peer-review a new study from Mexico using DBS to make patients less aggressive, where it is unclear how the patients were recruited and whether informed consent was gained. In China, it has been employed to counter heroin addiction.
"The slope is pretty slippery and it's a pretty long slope. There is almost nothing that is not possible [with DBS]," said Dr. Bernstein. "[But] if we go too far in our technological manipulation of people, of the brain, we are in danger of losing identity on an individual level and on a societal level."
After years of excitement about the technology's incredible potential, the ethics around it seem to be drawing increased attention. Canadian experts led discussion of the issues at a major U.S. bioethics conference this week. Dalhousie University is planning another symposium for next month. Those asking questions stress that deep-brain stimulation has done much good and that more benefits are sure to come to light, but say caution is needed given its unique capabilities.
Underlying the discussion is neurosurgery's most shameful hour: The widespread use of lobotomies in the 1940s and 1950s, with little supporting evidence and often devastating results.
Scientists note that DBS is different in many ways, not least because it is reversible. While lobotomies actually destroyed brain tissue, the stimulator can be turned off or even removed from the brain, usually without any damage.
But getting the patient's informed consent is a crucial pillar of any invasive treatment, and that becomes complicated with DBS, because the patients are often suffering from neurological or psychiatric conditions and the technology itself can affect their judgment.
One Dutch Parkinson's patient found that the stimulator embedded in his brain stopped his tremors, but seemed to trigger manic episodes: chaotic behaviour that led to serious financial debts, according to a 2004 journal paper. When the device was turned off, the mania disappeared but the Parkinson's tremors came back, and vice versa.
He was left with the troubling choice of keeping on the stimulator but having to be committed to a psychiatric hospital for the rest of his life, or turning it off and being confined, physically disabled, to a nursing home, noted Walter Glannon, a University of Calgary health sciences professor in a paper published this summer in the Journal of Clinical Ethics. The patient chose mania over the Parkinson's symptoms.
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