Repairing Brain Damage From Stroke May Be Possible With Brain Cell Transplants

"More research needs to be done, but these results are exciting," said Douglas Kondziolka, MD, of the University of Pittsburgh Medical Center in Pennsylvania. "Right now there is no direct treatment for reversing the neurologic damage of a stroke months after it occurs. The only treatment for these patients is rehabilitation through physical or occupational therapy."

In the study, transplants were given to 12 people whose stroke occurred six months to six years previously and who had major movement disabilities, which could be as severe as paralysis in an arm or leg. Six months after transplantation, none of the patients experienced complications or other problems related to the transplant.

"This study was designed to evaluate if it's feasible to put these cells into the brain and whether the process is safe," Kondziolka said. "With these positive results, now we can move on to a larger study with more patients to find out whether these transplants really help patients recover their lost abilities."

The patients received either two million or six million cells transplanted into three sites within and around the stroke-damaged areas of the brain. The cells, called LBS-Neurons, originate from human tumor tissue composed of embryonic-like cells. In the laboratory, scientists have developed a process that uses several chemicals to transform these rapidly dividing cells into fully differentiated, non-dividing neurons.

Six of the 12 patients improved substantially on tests of disability, mainly in tests of motor skills such as walking and arm and leg movement. Positron emission tomography (PET) scans showed a 15-percent improvement in metabolism in the area of the transplant in six of the patients, suggesting that the transplanted cells may be integrating with existing tissue and functioning.

"We can't draw any conclusions about the effectiveness of this therapy due to the small number of patients involved in the study," Kondziolka said. "But there were some trends indicating that patients were improving." Kondziolka noted that the signs of improvement were not consistent. Some patients had worse scores on the tests used to measure patients' disability after six months than they did at the time of the transplant, and some patients' scores stayed the same over the six months.

This work marks a transition in stroke medicine from prevention efforts and efforts to limit the damage from a stroke that occurred within hours to efforts to restore lost brain function from a stroke that occurred as long as six years before.

"To be able to produce some degree of recovery years after a stroke would be a remarkable achievement," said neurologist Justin Zivin, MD, PhD, of the University of California, San Diego, who wrote an editorial accompanying the Neurology study. "But it's too soon to know whether these transplants promise hope for patients disabled with stroke."

This is the first study to use cell transplants in stroke patients; fetal human and fetal animal cell transplants have been tried for neurodegenerative disorders such as Parkinson's disease. This is also the first brain cell transplant using tissue grown in a lab.

###The study was sponsored by Layton BioScience, Inc., the Atherton, Calif., company that produces the LBS-Neurons.

The American Academy of Neurology, an association of more than 16,000 neurologists and neuroscience professionals, is dedicated to improving patient care through education and research. A neurologist is a medical doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system.

For more information about the American Academy of Neurology, visit its Web site at http://www.aan.com.

For online neurological health and wellness information, visit NeuroVista at http://www.aan.com/neurovista.