Bad science revisited.(fetal brain tissue transplantation)(Brief Article)

NRL News readers may recall the startling news account that appeared last March, detailing the complete failure of efforts to transplant fetal brain tissue into patients with Parkinson's disease. Not only were there no improvements, but "in about 15 percent of patients, the cells apparently grew too well, churning out so much of a chemical that controls movement that the patients writhed and jerked uncontrollably," according to the March 6 New York Times.

One of the researchers involved in the study, Dr. Paul Greene, told Gina Kolata of the Times that some of the uncontrollable movements suffered by patients were "absolutely devastating."

"They chew constantly, their fingers go up and down, their wrists flex and distend," Greene said. Moreover, "the patients writhe and twist, jerk their heads, fling their arms about," Kolata wrote.

But now a researcher who helped run the Parkinson's disease fetal tissue transplant experiment that ended so dismally thinks he can explain at least part of the problem. He has reviewed the magnetic resonance imaging brain scans of the five patients who went on to develop this pattern of terrible, uncontrolled body movements (termed "dyskinesias"), and has made a discovery: the grafts were inserted in the wrong place.

"We have learned that it is possible to place grafts where they can cause mischief," said David Eidelberg, a Long Island physician who conducted the brain imaging of the patients during the study, in an interview with a New Scientist reporter published November 13.

He explained that the transplant team headed by Dr. Curt Freed of Colorado had placed the fetal cells into a deep brain nucleus called the putamen. Eidelberg now feels the putamen in these patients was still producing adequate amounts of the brain chemical dopamine, the neurotransmitter which generally runs low in Parkinson's disease which leads to muscle rigidity and slowness of movement.

The insertion of dopamine-producing fetal cells into this region resulted in an excess of dopamine, he surmised, causing the bizarre jerking movements characterized by fellow researcher Dr. Greene as "devastating."