Stroke patients walk again after stem cell injection

Patients with chronic stroke showed significant improvement in movement—such as walking and talking again—after receiving modified stem cells injected directly into the brain, according to a first-of-its-kind human trial reported June 2, 2016 in the journal Stroke.

“This wasn’t just, ‘They couldn’t move their thumb, and now they can.’ Patients who were in wheelchairs are walking now,” said the study's lead author Gary Steinberg, MD, PhD, Professor and Chair of Neurosurgery at Stanford University School of Medicine, in Stanford, CA.

This 2-year, open-label, single-arm trial involved 18 patients (average age of 61) with chronic motor deficits from a nonhemorrhagic stroke that had occurred at least 6 months (and up to 3 years) prior.

The study was intended largely to investigate the safety of the procedure, so researchers were surprised when patients showed significantly higher clinical scores on standard scales of stroke recovery—including a remarkable 11.4-point overall improvement on the motor-function component of the Fugl-Meyer scale, which specifically tests patients’ movement deficits.

“Their ability to move around has recovered visibly. That’s unprecedented,” Dr. Steinberg said. “At 6 months out from a stroke, you don’t expect to see any further recovery.”

“We thought those brain circuits were dead,” he said. “And we’ve learned that they’re not.”

Small pilot trials by other researchers had reported some functional benefits using transplanted neuronal cells in patients with stroke. But no current medical or surgical treatments have been proven to restore function in patients with subacute or chronic stroke.

For this study, the neurosurgeons injected the stem cells though a single craniostomy into the peri-infarct areas of the patient’s brains. These were SB623 cells, which are modified mesenchymal stem cells derived from bone marrow and designed to restore neurologic function.

“We know these cells don’t survive for more than a month or so in the brain,” Dr. Steinberg noted. “Yet we see that patients’ recovery is sustained for greater than one year and, in some cases now, more than two years.”

Improvements in patients’ clinical outcomes didn’t appear related to either stroke severity or patient age at baseline, the researchers noted.

“This was just a single trial, and a small one,” Dr. Steinberg acknowledged. But it has set the stage for a double-blinded, multicenter phase-2b trial, now getting under way.

“There are close to 7 million chronic stroke patients in the United States,” he observed. “If this treatment really works for that huge population, it has great potential.”