Preliminary Nature, Public Misconceptions of DBS Raise Ethical Challenges

by Aalok Mehta

November 17, 2008

Neurologists exploring deep brain stimulation (DBS) treatment face serious ethical challenges because of the technique’s preliminary nature and widespread public misconceptions, experts said at a Nov. 13 public forum on the technique.

In DBS therapy, surgeons implant a pacemaker-like device in the brain that can send out electronic impulses on command. Though the Food and Drug Administration has cleared DBS devices for the treatment of Parkinson’s disease and other movement disorders, some of the technique’s most-touted uses—such as treatment of severe depression and of people in vegetative states—remain in early stages of testing.

One problem, said Helen Mayberg, a professor of psychiatry and neurology at Emory University, is that many in the general public have already come to view DBS as an established procedure. Mayberg was speaking at a panel titled “Mind and Matter: Ethical Challenges of Deep Brain Stimulation,” sponsored by the Dana Alliance for Brain Initiatives and the Neuroethics Society in conjunction with the society’s inaugural annual meeting.

Treating depression “is a tremendous application of this technique,” Mayberg said. “But we are at a beginning, and we should act as such.”

This raises particular hurdles when dealing with patients who see DBS as their last resort, especially since many of them will not qualify for DBS trials. “Depression is a serious illness … if they’re not being treated, they will die—usually at their own hand,” she said. “How do we communicate to desperate patients and their families that we don’t know what we’re doing yet?”

Clearly outlining the significant risks of DBS is also important, she said. “There is no such thing as minor brain surgery, no matter what the surgeon tells you.”

Jonathan Moreno, a professor of medical ethics at the University of Pennsylvania, pointed out that new surgeries also are not as well-regulated as drugs and medical devices.

“There is no FDA for surgeries,” Moreno said, which leads to disagreements about what constitutes a surgical experiment versus what falls under routine procedure. “We think this is bad for patients and risky for surgeons,” he said.

Moreno and his colleagues decided to survey surgeons, and found that almost all favored regulatory reviews for experimental surgeries and a majority thought institutional review boards should clear procedures.

The potential of DBS to treat people in vegetative and minimally conscious states raises unique ethical issues, added Joseph Fins, chief of medical ethics at Weill Cornell Medical College and co-author of a landmark 2007 Nature paper showing improvement in a minimally conscious patient.

“We could not have done that trial without an ethical framework,” he said. But difficult questions popped up, such as what to do if a person improves enough to make decisions on his own again. Directly addressing how and when to reconsider consent was vital but controversial, Fins said.

Scientists might find it useful to communicate to the public two things about DBS, he added. For one, the technique might be best used for exploring the basic nature of neurological diseases, he said, “not just as a therapeutic tool.” And second, it’s on probation—“it’s not yet a vetted therapy.”

Philip Campbell, editor in chief of Nature and Nature Publications, shed some additional light on the problem of communication. “DBS is still a very crude, rudimentary intervention,” he said. “But it’s happening in the context of profound scientific illiteracy.”

Before problems and misconceptions about DBS can be solved, he added, scientists must build trust with the public. He suggested some ideas: The controversy over whether cell phones might cause cancer points out the importance of clearly communicating the risks and safeguards of experimental medical treatment, while climate change bloggers illustrate the power of directly addressing the public via the Internet.