Recovery in Motion

Stem Cell Transplants Improve Recovery in Animal Models for Stroke, Cerebral Palsy

A single dose of adult donor stem cells given to animals with neurological damage can significantly enhance recovery, researchers say.

Using a commonly utilized animal model for stroke, researchers administered 200,000 to 400,000 human stem cells into the brains of animals with significant loss of mobility and other functions. The stem cells used in the study were a recently discovered stem cell type called multipotent adult progenitor cells, or MAPCs.

Motor and neurological performance in the animals improved 25 percent, said Dr. Cesario V. Borlongan, a neuroscientist at MCG and Augusta’s Veterans Affairs Medical Center.

The findings were presented in April 2006 during the 58th annual meeting of the American Academy of Neurology in San Diego.

In humans, the findings ideally will translate into incremental but important recovery advances, said Dr. David Hess, chair of the MCG Department of Neurology and a study coauthor.

“The single largest cause of disability among adults in the U.S. is stroke,” said Dr. Hess. “It’s a huge public health problem in the world.” He hopes stem cell therapy, aggressive physical therapy and the clotdissolving drug, tPA, can work synergistically to reduce that disability.

“These are not going to be cures, but this level of recovery is significant. If somebody can go from a wheelchair to a cane, that is a big improvement,” Dr. Hess said.

Adult animals were tested across a range of standardized tasks both before and after a surgically induced stroke.

Following the stroke, both control animals and those that received a single injection of stem cells were evaluated for up to two months. Animals treated with stem cells had improved strength, balance, agility, fine motor skills and tissue recovery.

“A single dose of the cells produce robust behavioral recovery at an early period posttransplantation, and the recovery was durable, lasting up to two months, which was the entire length of this study,” Dr. Borlongan said. “Furthermore, animals continued to show improvement over time.” In the newborn model of ischemic injury, enhanced recovery took place within two weeks.

Even though fewer than 1 percent of the transplanted cells were present two months later, animals receiving treatment developed new neurons, apparently formed from endogenous stem cells. “The mechanism that we are putting forward is these donor cells are secreting nourishing trophic factors that are helping the host brain cells survive and stimulating stem cells from the host to multiply,” Dr. Borlongan said.

To help mimic potential clinical scenarios for stroke victims, transplants were performed seven days after the initial injury. The drug, tPA, must be administered within three hours of a stroke, a window most patients miss.

In the adult stroke model, MC