Stroke patients are walking and talking thanks to stem cell brain injections

Signs from a recent trial suggest we’ve massively misjudged the brain’s ability to repair itself, as injections of stem cells have led to “remarkable” improvements in mobility and speech in stroke patients.

The trial, run by a company called SanBio in California, tested how stem cell injections into a patient’s brain can improve recovery from a stroke. Of the 18 people in the trial, all of them reportedly showed some signs of improvement to mobility.

“One 71-year-old woman could only move her left thumb at the start of the trial,” Gary Steinberg, a neurosurgeon at Stanford University who performed the procedure, told New Scientist. “She can now walk and lift her arm above her head.”

All of the patients in the trial had suffered a stroke between six months and three years before the study, with improvements to their mobility having plateaued. The results were measured on a scale of one to 100, with 100 being total mobility. On average, the patients’ scores were found to jump 11.4 points, which the researchers qualify as “clinically meaningful”.

The injected material was made up of mesenchymal stem cells, extracted from the bone marrow of two donors. These cells were genetically engineered to contain a gene called Notch1, which helps certain aspects of brain development in infants. Steinberg injected the cells, via a borehole in the skull, directly into sections of the brain responsible for motor movements.

“The most dramatic improvements were in strength, coordination, ability to walk, the ability to use hands and the ability to communicate, especially in those whose speech had been damaged by the stroke,” said Steinberg.

Part of the reason the brain was able to repair itself so well is thought to be due to the cells making the adult brain more like the brain of a baby. Talking to New Scientist, Steinberg said the cells activate a range of growth factors, and alter the immune system “to get rid of inflammation that otherwise obstructs repair.”

This is the second trial that has investigated the use of stem cells in the brains of stroke patients. The first was carried out in the UK last year by a company called ReNeuron, and similarly reported improvements in the limb functionality of its subjects.

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