MEDICINE / HUNTINGTON’S DISEASE : Controversial Brain Graft Performed
The Mexican neurologist who was the first to use brain grafting to treat Parkinson’s disease has come up with another controversial first in the world of neurology.
Dr. Ignacio Madrazo of the Instituto Mexicano del Seguro Social in Mexico City will report today at a meeting of the Society for Neuroscience in New Orleans that he has transplanted fetal cells into the brain of a victim of Huntington’s disease, a debilitating, inherited disorder that is normally fatal by age 50.
Madrazo performed the transplant just over a year ago, using brain cells from a 13-week-old fetus that had aborted spontaneously. Madrazo was also the first to use cells from aborted fetuses for the grafting for Parkinson’s.
Recent neurological testing of the 37-year-old woman who received the transplant, as well as subjective accounts of her performance by her family, “reveal slight improvements in gait, facial movements, spasmodic and uncoordinated movements,” Madrazo said Monday in a telephone interview. “Her speech and intellectual function have also shown some improvement. We believe that if the graft remains viable, the neurological condition of this patient can be expected to improve in the course of the next three years.”
Although experiments in animals have suggested that brain grafting should be beneficial in Huntington’s, other researchers argued that Madrazo’s attempt is premature. Neurologist John Sladek of the Chicago Medical School was particularly critical. “I believe that this experiment was performed too soon and (should have been preceded by) appropriate pre-clinical testing,” he said.
Nonetheless, researchers will follow the patient’s progress closely because many experts say such grafting represents the best hope yet for treating Huntington’s patients. No other form of therapy exists.
About 25,000 Americans have Huntington’s and another 150,000 have a 50% chance of developing the disorder because one of their parents had it. Researchers have developed a genetic test that identifies individuals who will develop the disorder, but have not yet identified the defective gene that causes it.
Tests in animals have shown promise that brain grafting will be successful in treating Huntington’s. At the New Orleans meeting, for example, neuroscientist Ole Isacson and his colleagues at the Harvard Medical School reported that grafting fetal nerve cells into the brains of primates with the movement disorder associated with Huntington’s produced marked improvement in the animals’ conditions.
When the graft was removed, Isacson found, the movement disorder returned, indicating that the fetal cells themselves were the source of the improvement, rather than some generalized effect associated with the surgical procedure.
Such successes in animals, combined with the demonstrated effectiveness of brain grafting in Parkinson’s victims and the importance of even minor improvements in the symptoms of Huntington’s patients, “clearly motivate the application of the transplantation approach to patients with Huntington’s,” said neurologist Olle Lindvall of the University of Lund in Sweden.
But Lindvall, Sladek and others found much to fault in Madrazo’s procedure. Among other problems, he did not inject the fetal cells into the precise site in the patient’s brain where they could do the most good, nor did he show that the fetal cells were alive before he transplanted them. And he only implanted them on one side of the brain, whereas Huntington’s affects both sides.
Madrazo countered that he had used the same surgical procedure he had adopted in previous brain grafts and that he is sure the cells were alive at the time of the graft. And by grafting the cells to only one side of the brain, he added, he is able to study differences in response by those areas of the brain receiving chemicals from the graft and those which do not.
