Stem Cells Show Promise for Stroke Recovery
Early study found they can be safely transplanted into the brain; 2 patients showed significant improvement
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.
None of the patients showed any signs that their bodies were rejecting the foreign cells.
In addition to safety, researchers looked for signs that the cells had improved stroke symptoms. Most patients made gradual progress. By six months, all the patients demonstrated improvement in their weakness or paralysis on three different tests of post-stroke function, the researchers said.
But two patients in particular piqued researchers' interest.
"We had two patients who had remarkable recoveries," said study author Dr. Gary Steinberg, chairman of neurosurgery at Stanford University.
Both were women. One was 71, while the other was 33.
"They were very disabled. The 71-year-old could only move her left thumb. She couldn't move the arm or hand and could barely get her leg off the bed," he said.
"The day after surgery, she was lifting her arm over her head, and lifting her leg off the bed. She's walking now. She was wheelchair-bound before," Steinberg added.
Similarly, the 33-year-old had a severe speech deficit and had trouble holding her arm up. Steinberg said the day after surgery she was lifting her arm over her head. A year later, her gait and speech have improved.
Steinberg cautioned that these "miracle-type" recoveries are not typical. And because there was no control group in the study, it's impossible to say whether it was the stem cells or something else about the procedure that helped the women.
"We never would have expected two years or more out that patients could recover from a stroke," said Steinberg. "We thought the circuits were dead. Now we know they're still viable. We just have to know how to activate them."