While new tools have emerged to help rehabilitation along, the road back to a healthy life after suffering a stroke can be a long and challenging one. In research that could one day significantly cut recovery times for victims of these debilitating brain injuries, scientists have injected modified stem cells into the brains of patients and brought about substantial improvements to motor function, with one even regaining control of her limbs and leaving her wheelchair behind.
Around 15 million people suffer a stroke each year, according to the World Stroke Organization. The majority of these are classed as ischemic, which means that a clot has formed in a vessel carrying blood to a section of the brain to cut of its supply.
Immediate treatment to dissolve the clot in an ischemic stroke will boost the chances of a full recovery, but with only three or four hours to get to a hospital to have the clot-busting drugs administered, many victims miss this critical window and wind up sustaining lifelong disabilities.
In search of a way to improve the lives of these sufferers, scientists at Stanford University conducted a trial involving 18 stroke victims and mesenchymal stem cells, which are natural precursors to muscle fat, bone and tendon tissues, and can mature into multiple types of specialized cells in the body. These cells were modified to boost their ability to restore brain function.
The average age of the patients was 61 and all had experienced their first strokes between six months and three years earlier. They were conscious throughout the process but placed under light anesthesia, with the scientists drilling a small hole through their skulls and injecting the stem cells into different locations at the periphery of the affected areas. The patients were sent home the next day, but were monitored with blood tests, clinical assessments and brain imaging thereafter.
These observations found that the patients showed significant improvements, which continued even up to 12 months after the procedure. The team says this is likely a result of the factor secreted by the cells soon after the injections into the stroke site, which brought about lasting regeneration of nearby tissue.
"We know these cells don't survive for more than a month or so in the brain," says Gary Steinberg, chair of neurosurgery at Stanford Medicine. "Yet we see that patients' recovery is sustained for greater than one year and, in some cases now, more than two years."
Improvements made by the patients are described as substantial, but particularly impressive were those made by Sonia Olea Coontz, who had lost function completely of her right arm and partially of her right leg. This left her walking with a limp and often using a wheelchair to get around, but the treatment led to her regaining mobility in her limbs and leaving her wheelchair behind.
"After my surgery, they woke up," she said.
The patients scores on common metrics of stroke recovery were vastly improved, with one making an 11.4-point gain on the Fugl-Meyer test, which is designed to measure ones' movement deficits. Aside from passing headaches after the surgery, no patients showed side effects that could be attributed to the stem cells.
"This was just a single trial, and a small one," says Steinberg. "It was designed primarily to test the procedure's safety. But patients improved by several standard measures, and their improvement was not only statistically significant, but clinically meaningful. 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."
The team says that the promising results indicate that other neurodegenerative conditions and brain injuries could benefit from the approach. Steinberg is now setting up a randomized, double-blinded trial that will involve 156 chronic stroke patients to further explore its effectiveness.
The research was published in the journal Stroke.
Source: Stanford University
