Stanford researchers studying the effect of stem cells injected directly into the brains of stroke patients said Thursday that they were "stunned" by the extent to which the experimental treatment restored motor function in some of the patients. While the research involved only 18 patients and was designed primarily to look at the safety of such a procedure and not its effectiveness, it is creating significant buzz in the neuroscience community because the results appear to contradict a core belief about brain damage that it is permanent and irreversible.
The results, published in the journal Stroke, could have implications for our understanding of an array of disorders including traumatic brain injury, spinal cord injury and Alzheimer's if confirmed in larger-scale testing.
The work involved patients who had passed the critical six-month mark when recoveries generally plateau and there are rarely further improvements. This is the point at which therapies are typically stopped as brain circuits are thought to be dead and unable to be repaired. Each participant in the study had suffered a stroke beneath the brains outermost layer and had significant impairments in moving their arms and-or legs. Some participants in the study had had a stroke as long as three to five years before the experimental treatment.
The one-time therapy involved surgeons drilling a hole into the study participants' skulls and injecting stem cells in several locations around the area damaged by the stroke. These stem cells were harvested from the bone marrow of adult donors. While the procedure sounds dramatic, it is considered relatively simple as far as brain surgery goes. The patients were conscious the whole time and went home the same day.
They suffered minimal adverse effects such as temporary headaches, nausea and vomiting. One patient experienced some fluid buildup from the procedure that had to be drained but recovered fully from the issue. The volunteers were then tested at one month, six and 12 months after surgery using brain imaging and several standard scales that look at speech, vision, motor ability and other aspects of daily functioning.
Gary Steinberg, the study's lead author and chair of neurosurgery at Stanford, said in an interview that while he is cautious about "overselling" the results of such a small study, his team has been "stunned" that seven of the 18 patients experienced significant improvement in their abilities following treatment.
"Their recovery was not just a minimal recovery like someone who couldn't move a thumb now being able to wiggle it. It was much more meaningful. One 71-year-old wheelchair-bound patient was walking again," said Steinberg, who personally performed most of the surgeries.
He also recounted the progress of a much younger patient, age 39, who was two years post-stroke and had had such problems walking and speaking that she "did not want to get married to her boyfriend." "She was embarrassed about walking down the aisle," he explained. But after treatment, Steinberg said, "She's now walking much better and talking much better and she's married and pregnant."
