Brain Circuits Thought Long Dead After Stroke Might Just Be Dormant

Nov 30, 2017
Originally published on November 30, 2017 2:42 pm

Doctors involved in a study using adult stem cells to treat stroke patients were shocked at how successful the therapy was in some cases. While patients generally show very little improvement after six months, a few regained movement and speech years later.

Here & Now‘s Robin Young talks with Dr. Gary Steinberg, professor and chair of neurosurgery at Stanford University and the lead researcher on the project.

Interview Highlights

On how adult stem cells work

“There are many types of stem cells, of course. Adult stem cells are one particular type. And they have the ability to turn into certain kinds of cells in the body. But the interesting thing in terms of what we did is that these cells don’t actually integrate into the brain long term and become neurons to reconstitute circuits. What they do is to pump out very powerful growth factors, molecules and proteins that enhance native mechanisms of recovery, such as new synapses of neurons that are there, new blood vessels, and they have a very profound effect on modulating the immune system. And in that way, what we believe they do is to turn the adult brain into a neonatal or infant brain, which has a lot of ability to recover after injury.”

On the study revealing that what wasn’t functioning in some stroke patients’ brains was actually dormant, rather than dead

“That was something we didn’t expect. We were very pleased to see that the study, in 18 patients, showed that the transplant of these stem cells into the brain in chronic stroke patients was safe and feasible, but we were stunned to find that the patients improved. Overall, three-quarters of the patient showed a, what’s called ‘meaningful recovery’ over a course of six months, sustained at 12 months and now we know it’s sustained at 24 months. That means their life was made better, and we had a couple of miracle patients who showed very, very dramatic recovery.”

On the process of injecting the stem cells

“So what we do is to attach a, what’s called the stereotactic frame, to the head. It’s like a GPS system of guidance for the brain, and that allows us to implant the cells around the stroke with submillimeter accuracy. Then we make a little hole about the size of a nickel in the bone, and using a very fine needle, we transplant the cells into the area just surrounding the stroke — not directly in the stroke, because that’s a very inhospitable environment. But the cells survive just outside the stroke, and they somehow do their thing to resurrect the circuits.”

On how stem cells helped Sonia Coontz, who suffered a stroke in 2011

“Sonia, it was two years out from a stroke that affected her left brain, so she was unable to move her arm or hand at all. She could walk with great difficulty, she didn’t wanna get married because she felt she’d be embarrassed walking down the aisle, and you couldn’t understand her speech. After we transplanted the cells, she made a dramatic and near-miraculous recovery, to the point she’s walking well, she got married, she had a baby boy 14 months ago, who’s doing very well. And her speech, while not completely normal, is very, very understandable.”

On cautions when it comes to the study’s results

“We’re very excited about these results. However, we don’t wanna overpromise. This was an early phase study, only 18 patients, we just completed enrollment in a larger, multi-center, double-blind controlled study of 156 patients throughout the country, where a third of the patients do not get the cells, they only get a partial hole in the skull. And the only people who know are the seven or eight people in the operating room who did the procedure. So we’ll have the results of this larger phase two study in about a year and a half, and if that confirms what we found in the first study, it would lead to a definitive phase three study of several hundred patients with controls. And if that’s positive, and shows benefit, we’ll be able to commercialize the technique, and it’ll become available for everybody.”

On the magnitude of the findings

“I’m shocked. To tell you the truth, even 10 years ago, we couldn’t dream about recovering function in patients with neurologic disorders and disability. Now we know that those circuits, which we thought were irreversibly damaged or dead, are not. We just have to figure out how to resurrect them. And it may apply to disorders other than stroke, such as spinal cord injury, traumatic brain injury and even degenerative diseases like Parkinson’s disease, Lou Gehrig’s disease and maybe even Alzheimer’s disease.”

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