An anonymous reader quotes a report from The Washington Post: 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. 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. Each participant in the study had suffered a stroke beneath the brain's outermost layer and had significant impairments in moving their arms and-or legs. 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. They suffered minimal adverse effects such as temporary headaches, nausea and vomiting. "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, the study's lead author and chair of neurosurgery at Stanford who personally performed most of the surgeries. Steinberg said that the study does not support the idea that the injected stem cells become neurons, as has been previously thought. Instead, it suggests that they seem to trigger some kind of biochemical process that enhances the brain's ability to repair itself. "Patients improved by several standard measures, and their improvement was not only statistically significant, but clinically meaningful," Steinberg said. "Their ability to move around has recovered visibly. That's unprecedented. At six months out from a stroke, you don't expect to see any further recovery."