Surgery for Parkinson’s Sparks Debate
Burning a small hole in patients’ brains can eliminate the most serious symptoms of Parkinson’s disease in 85% of patients receiving the disputed treatment, a controversial Southern California surgeon reports today.
The experimental procedure, known as a pallidotomy, is being widely adopted as a surgical approach to the disabling disorder that afflicts as many as 1 million Americans. Dr. Robert P. Iacono of Loma Linda University Medical Center is one of its most high-profile proponents, having performed pallidotomies on more than 500 Parkinson’s patients.
Critics have charged that Iacono’s version of the surgery has an unacceptably high rate of complications and that he has failed to publish his procedures and results. Today’s paper by Iacono in the journal Neurosurgery is his first answer to those critics, detailing the outcome of the surgery in his initial 126 patients.
He reports that pallidotomies greatly reduced the tremors, erratic movements and impaired motion associated with Parkinson’s in the vast majority of the patients, and that the rate of complications, mostly from bleeding in the brain, was only 6.3%.
However, other researchers charge that the complication rate is still too high, that Iacono’s patients have not been studied long enough to evaluate the procedure’s long-term effectiveness and that their conditions should have been evaluated independently by other neurologists.
“Dr. Iacono and colleagues have undoubtedly overestimated their surgical success and underestimated their surgical complication rate,” said Dr. Roy A. E. Bakay of Emory University, where controlled trials of the technique are in progress.
Such independent evaluation is crucial, said Dr. Patrick J. Kelly of the New York University Medical Center, because “as we have learned before, surgery in Parkinson’s disease patients has a marked placebo value for both patients and surgeons.”
But, Iacono said, “a placebo effect won’t give you an 18-month result.”
The doubts about pallidotomies were highlighted by a second report in the same journal from Dr. Cheryl H. Waters and her colleagues at USC Medical School. Only one of five patients they treated received any benefit from the procedure, Waters said, and her team has revised its surgical procedures. Nonetheless, she said in an interview, “the surgery definitely has a role in the armamentarium of treatment. . . . It’s not for everyone, however.”
Kim Seidman, West Coast director of the American Parkinson’s Disease Assn., said, “Pallidotomies have the potential to be a truly helpful procedure for some patients.” But, she said, the group does not refer Parkinson’s patients to Iacono for surgery “on the advice of our national medical advisory board.”
Parkinson’s strikes as many as 100,000 Americans each year, most over 55. The disorder, whose cause is unknown, is characterized by severe tremors and rigidity in the limbs and loss of muscle control. As many as one-third of Parkinson’s patients also develop dementia.
The disorder results from the death of brain cells that produce a neurotransmitter called dopamine, which plays a key role in transmitting commands from the muscle control centers. The disorder is treated with a drug called L-dopa, which alleviates symptoms by producing dopamine in the brain.
Although L-dopa is an effective therapy for Parkinson’s, many patients become hypersensitive to it over time. The drug accentuates their herky-jerky movements and other symptoms during the so-called “off” periods, when symptoms are at their worst.
