Researchers from the University of Missouri, in a recent study, share evidence they have found of the specific neurochemical changes in the brain that occur in the case of hand amputation or reattachment.
Some of these changes in the brain may persist in individuals who receive hand transplants, despite their recovered hand function, according to the study, published recently in Journal of Neurophysiology.
“When there is a sudden increase or decrease in stimulation that the brain receives, the function and structure of the brain begins to change,” says Carmen M. Cirstea, MD, PhD, research assistant professor of Physical Medicine and Rehabilitation and lead author of the study, in a media release from University of Missouri-Columbia.
“Using a noninvasive approach known as magnetic resonance spectroscopy (MRS) to examine areas of the brain previously involved with hand function, we observed the types of changes taking place at the neurochemical level after amputation, transplantation or reattachment.”
In the study, Cirstea, along with co-author Scott Frey, PhD, the Miller Family Chair in Cognitive Neuroscience in the Departments of Psychological Sciences and Neurology, used MRS to evaluate the neuronal health and function of nerve cells of current hand amputees, former amputees, and healthy subjects.
The researchers instructed volunteers to flex their fingers to activate sensorimotor areas in both sides of the brain. They then analyzed N-acetylaspartate (NAA) levels, a chemical associated with neuronal health. According to their findings, NAA values for the reattachment and transplant patients were similar to levels of amputees and significantly lower than the healthy control group, the release continues.
“Previous research has found substantial reorganizational changes in the brain following limb injuries that decrease sensory and motor stimulation following limb injuries,” Frey states. “These findings show that after surgical repairs, the effects of nerve injuries on the mature brain may continue even as former amputees recover varying degrees of sensory and motor functions in replanted or transplanted hands.”
Due to the small number of reattachment and transplant patients they studied (five), the researchers conclude in the release that the results should be interpreted with caution until more work is completed.
[Source(s): University of Missouri-Columbia, Science Daily]