Primates with severe Parkinson's disease were able to walk, move, and eat better, and had diminished tremors after being injected with human neural stem cells, a research team from Yale, Harvard, the University of Colorado, and the Burnham Institute report in Proceedings of the National Academy of Sciences.
These results are promising, but it will be years before it is known whether a similar procedure would have therapeutic value for humans, said the lead author, D. Eugene Redmond Jr., professor of psychiatry and neurosurgery at Yale.
"Not only are stem cells a potential source of replacement cells, they also seem to have a whole variety of effects that normalize other abnormalities," Redmond said. "The human neural stem cells implanted into the primates survived, migrated, and had a functional impact. It's an important step, but there are a number of studies that need to be done before determining if this would be of any value in clinical settings."
Parkinson's disease is caused by a degeneration of dopamine neurons in an area of the midbrain known as the substantia nigra, which is responsible for dopamine production. Reduced production of dopamine in late stage Parkinson's causes symptoms such as severe difficulty in walking, fewer movements, delays in moving, lack of appetite, difficulty eating, periods of remaining motionless known as freezing," and head and limb tremors.