April 28, 2004
|April 28, 2004
An innovative form of brain surgery may one day offer help for the fading memory of Alzheimer's disease, researchers report. The experimental technique involves injecting genetically modified cells deep into a part of the brain critical for learning and memory. It has only been tried in a small number of people, though, and years of additional research will likely be needed before it is known if it is truly effective and safe as a treatment for Alzheimer's or other brain disorders.
Researchers at the University of California, San Diego tested the brain therapy in eight men and women, ranging in age from 53 to 76, who were in the early stages of Alzheimer's disease. Living skin cells taken from each patient were modified in the laboratory to produce a protein called nerve growth factor (NGF). In animal experiments, NGF has been shown to protect and rejuvenate brain cells, including those that deteriorate in Alzheimer's disease. Once the genetically modified cells have been injected into the brain, the engineered gene continues to generate NGF.
One year later, the injections appeared to be safe for most of the study volunteers, although one man who received the treatment later died of a heart attack several weeks after having surgery. What's more, those who received the treatment had, on average, half the rate of deterioration in memory function that they had before the treatment. High-tech imaging with a technique called PET scans revealed that the treatments also caused more overall activity in patient's brains.
"These results are intriguing," says Mark Tuszynski, M.D., Ph.D., professor of neurosciences at the UCSD School of Medicine. "If these effects are borne out in larger, controlled trials, this could be a significant advance over existing therapies for Alzheimer's disease."
Much more study will need to be done to determine whether this or other forms of gene therapy can indeed help those with Alzheimer's. Although it is not seen as a cure, researchers are hopeful that such an approach may offer a new avenue of attack against the progressive downhill course of the illness.
The technique will be tried in a larger number of volunteers during a second phase of the test. That upcoming trial, which will start in the next few months, will be conducted among 40 or more people at the Rush University Alzheimer's Disease Center in Chicago. Other tests are scheduled in which NGF and other potentially beneficial substances will be administered directly into the brain via an implantable pump, rather than by cell implantation.
The early results were reported at the recent annual meeting of the American Academy of Neurology in San Francisco.
M. Tuszynski, La Jolla, L. Thal, et al: "A Phase I Trial of Nerve Growth Factor Ex Vivo Gene Therapy for Alzheimer's Disease." Presentation at the 56th Annual Meeting of the American Academy of Neurology, April 27, 2004, San Francisco, CA.