Intravenous injection of bone marrow derived stem cells in patients with spinal cord injuries led to significant improvement in motor functions, researchers from Yale University and Japan have reported. For more than half of the patients studied, substantial improvements in key functions—such as ability to walk, or to use their hands—were observed within weeks of stem cell injection, the researchers report. No substantial side effects were reported. The patients had sustained non-penetrating spinal cord injuries, in many cases from falls or minor trauma, several weeks prior to implantation of the stem cells. Their symptoms involved loss of motor function and coordination, sensory loss, as well as bowel and bladder dysfunction. The stem cells were prepared from the patients’ own bone marrow, via a culture protocol that took a few weeks in a specialized cell processing center. The cells were injected intravenously in this series, with each patient serving as their own control. Results were not blinded and there were no placebo controls.