Stem Cells Show Promise for Stroke Recovery
Early study found they can be safely transplanted into the brain; 2 patients showed significant improvement
In animal studies, stem cells have shown great potential to help heal the brain damage caused by strokes.
The new research is one of the first tests of the treatment in humans, the researchers said.
Participants in the new study ranged in age from 33 to 75. Each had experienced a stroke caused by a blood clot at least six months before their procedures. And each had been left with some weakness or paralysis in a limb.
The stem cells used in the study came from bone marrow donated by two people who were unrelated to the study participants. Special cells called mesenchymal stem cells were isolated from the marrow and grown in a lab, where they were treated with a gene that's thought to enhance their healing abilities.
Study participants were tested to make sure their bodies wouldn't reject the stem cells, but they weren't given any immune-suppressing medications.
Surgeons used a computer to sync images from MRI and CT scans, to form a three-dimensional picture of the stroke-damaged areas within the brain.
Patients were awake, but sedated, when surgeons drilled a nickel-sized hole in their skulls. Doctors used three passes with long needles to place 15 deposits of stem cells around the border of the damaged tissue. Six patients got a dose of 2 million cells, another six got 5 million, and the last six got 10 million cells, according to the report.
In animal studies, research has suggested that stem cells injected into the brain don't regrow damaged tissue.
"What these cells seem to do instead is to modulate repair processes. They don't replace the damaged brain so much as massaging the bits that are left, to get maximum function out of them," Cramer explained.
The study was primarily designed to evaluate the safety of this kind of stem cell transplant. Researchers said they were pleased with the results on that score.
Three patients suffered adverse events that were related to the brain surgery. One developed bleeding between the brain and skull. Another patient suffered a seizure, while a third developed pneumonia. All recovered after treatment.