Stroke is the leading cause of permanent disability in the U.S., striking nearly 800,000 people each year, according to the Centers for Disease Control and Prevention. In the last decade, there has been preclinical research that led to a small number of early phase clinical trials using mesenchymal stem cells (MSCs) as a possible treatment to reverse damage from hemorrhagic stroke. That’s the type of stroke in which a blood vessel breaks, causing bleeding on the brain. Within minutes, brain tissue starts to die which may cause paralysis, loss of speech or other disabilities. In a recent paper, Mayo Clinic researchers review the current studies using MSC therapy for hemorrhagic stroke in an effort to summarize the status of research and discuss the advantages and limitations of the various studies. The goal is to determine whether continued research around stem cell therapy for stroke patients would be warranted.

MSCs are an example of adult stem cells. They can be isolated from several tissues and differentiated into other cell types including, possibly, neurons. Researchers are trying to discover whether use of MSCs is beneficial in promoting repair of injured brain tissue.

“After more than 10 years of preclinical research looking at MSC therapy for hemorrhagic stroke in animal models, this review is a step towards translation from preclinical data to human trials in an effort to build consensus around the safety and tolerability of MSCs to guide future research, says Toni Turnbull, Ph.D., Mayo Clinic research fellow and lead author of the paper.

The researchers found that clinical trials using MSC therapy for hemorrhagic stroke are currently limited; however, initial positive preclinical and clinical results strongly suggest that further investigation into MSC therapy for hemorrhagic stroke is timely.

“Through our review, we found that preliminary evidence indicates that MSCs are both safe and tolerable in patients, says Mayo Clinic neurologist and critical care expert William Freeman, M.D. “However future randomized controlled trials are required to translate the promising preclinical research into an effective and validated therapy for hopeful patients.”

Researchers emphasize that timing, dosage and route of administration are all variables that need to be considered, controlled for and tested.

“Given the devastating effects of hemorrhagic stroke, and the millions of patients it affects, there is an understandable drive to develop this therapy for human use,” says Dr. Turnbull. “Additional studies will be needed to determine whether stem cells hold promise as a treatment option for stroke and other neurological disorders.”

This story originally appeared on Mayo Clinic’s Center for Regenerative Medicine blog.

Tags: Center for Regenerative Medicine, Progress Updates, regenerative medicine, republished, research, stem cells, stroke, Toni Turnbull, William Freeman