Skip to main content
Family of four plays at the beach with coastline in background

Repairing the brain with stem cells after stroke

December 03, 2019 | UCI Health
doctors looking at brain scans

Stroke is the No. 1 cause of long-term disability in the United States. Each year more than half of the 800,000 Americans who suffer an ischemic stroke are left with some lasting impairment.

The UCI Alpha Stem Cell Clinic is testing a promising new therapy aimed at regaining lost function after a stroke. As part of a national study known as PISCES III, UCI researchers hope to enroll six to 10 patients in the Phase 2b clinical trial. A total of 110 patients will participate across multiple U.S. sites.

Most strokes are caused when a clot blocks the flow of blood to the brain. Brain cells die when deprived of blood. The result of these ischemic strokes can be a range of disabilities, including problems with memory, language, thinking, emotions and motor control.

Regrowing brain cells

Stem-cell therapy offers the potential to bring back some motor function,” says Dr. Leonid Groysman, associate professor of neurology at UCI School of Medicine and the trial’s principal investigator at the stem cell clinic, the clinical arm of the UCI Sue & Bill Gross Stem Cell Research Center.

“The idea is that the implanted stem cells improve our own natural capacity to regrow brain cells.”

In a single surgical procedure, the stem cell therapy drug or a placebo is injected into the affected area of the brain. Researchers then follow trial participants for 12 months to assess their medical condition and functional status.

The study is aimed at stroke survivors between ages 35 and 75 who have some residual arm movement and have been stabilized for six to 12 months after an ischemic stroke. Patients may be eligible if they still have moderate or moderately severe disability.

Some improvements shown

Earlier phases of the PISCES III trials, which were designed to test the safety of modified progenitor cells, found no serious side effects from the therapy. The earlier studies were not designed to demonstrate functional improvement, but researchers were surprised when some participants showed significant improvements in arm and leg function over a 12-month period after the stem cell transplant.

“This was a huge surprise to the researchers,” Groysman says. “Patients continued to improve after a single injection. The feeling is that it set a regenerative process in motion. Our participation in this trial is exciting.”

He cautions that the work is still in the early stages: “We are searching for the right cells, the right method of delivery and the right timing.”

Stem cell therapies also are showing promise for other pathologies — such as dementia and blindness — which gives Groysman hope that treatment to help stroke patients regain lost function may be just around the corner.

New frontier for stroke treatment

In recent years, clot-busting drugs and prompt medical intervention have shown some success in dissolving or removing clots when performed immediately after the onset of a stroke. Research at UCI and other universities show that post-stroke rehabilitation therapies can help improve function and doctors encourage lifestyle modifications to prevent future stroke.

However, no treatments have been found to reverse disabilities resulting from stroke.

“Growing up watching my grandfather confined to his home after a stroke and realizing my inability to help him even with my medical training in neurology, I never thought that there would be a way for stroke patients to regain function,” Groysman says.

“Now maybe what we researchers were dreaming 20 or 30 years ago is coming true.”

The UCI Alpha Stem Cell Clinic (ASCC) is the clinical trials arm of the UCI Sue & Bill Gross Stem Cell Research Center (SCRC) and part of a network of the state's leading medical centers funded by the California Institute of Regenerative Medicine (CIRM). The ASCC specializes in delivering leading-edge stem cell clinical trials to patients and seeks to accelerate the development of treatments through partnerships with patients, medical providers and clinical trial sponsors. The ASCC network supports both CIRM-funded clinical trials and those funded by academic and industry sponsors. Visit to learn more about ASCC, clinical stem cell trials and regenerative medicine research at UCI.

Related stories