Key Points
Modified stem cells restore brain activity after stroke
Therapy effective even a month after brain injury
Clinical trials show potential for limb movement recovery
For survivors of the most common type of stroke, called an ischemic stroke, only about 5 per cent fully recover. Stroke patients generally suffer from long-term problems, including weakness, chronic pain, or epilepsy.
Scientists at Gladstone Institutes showed that a cell therapy derived from stem cells can restore normal patterns of brain activity after a stroke. Most treatments turn effective only after being administered in the immediate hours after a stroke, the new therapy, tested in rats, appeared beneficial even when given one month later.
The new study, published in the journal Molecular Therapy, is the first to detail the effects of stem cells on brain activity. The findings could lead to improvements in stem cell therapy. It may also contribute to the development of other treatments with similar impacts on the brain.
In the new study, the team tested the novel stem cell therapy in rats. The therapy has been in clinical development for more than a decade to treat stroke and traumatic brain injuries.
Clinical trials have already indicated that, in some patients, the stem cells could help people regain control of their arms and legs.
However, scientists were unsure what changes in the brain contributed to these improvements in symptoms.
The team led by Jeanne Paz injected modified human stem cells into the animals' brains near the site of injury, a month after suffering a stroke.
To probe the benefits, the scientists measured electrical activity in the brains. Individual cells and molecules were also analysed. The results showed reversed brain hyperexcitability in rats with strokes. This helped restore balance in neural networks.
Further, the treatment also increased the number of proteins and cells that are important for brain function and repair. While fewer than one per cent of the human cells remained in the rats' brains after a week following the transplant -- the effects of the transplants were long-lasting, Paz said.
