The effects of amputation on the brain may continue even as amputees recover sensory and motor functions in transplanted hands.
Changes in the brain can persist in individuals who receive hand transplants.
The amputation of a limb severs nerves that control sensation and movement, but also leads to dramatic changes in areas of the brain that controlled the functions of the lost limb. Researchers from the University of Missouri have found evidence of specific neurochemical changes associated with lower neuronal health in these brain regions. Further, they report that some of these changes in the brain may persist in individuals who receive hand transplants, despite their recovered hand function.
“When there is a sudden increase or decrease in stimulation that the brain receives, the function and structure of the brain begins to change,” said lead author Carmen M. Cirstea. “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.”
Cirstea, with co-author Scott Frey, 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. The research team then analyzed N-acetylaspartate (NAA) levels, a chemical associated with neuronal health. The researchers found that NAA values for the reattachment and transplant patients were similar to levels of amputees and significantly lower than the healthy control group.
Frey noted, “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 studied, the researchers said that the results should be interpreted with caution until more work is completed.
The amputation of a limb severs nerves that control sensation and movement, but also leads to dramatic changes in areas of the brain that controlled the functions of the lost limb. Researchers from the University of Missouri have found evidence of specific neurochemical changes associated with lower neuronal health in these brain regions. Further, they report that some of these changes in the brain may persist in individuals who receive hand transplants, despite their recovered hand function.
“When there is a sudden increase or decrease in stimulation that the brain receives, the function and structure of the brain begins to change,” said lead author Carmen M. Cirstea. “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.”
Cirstea, with co-author Scott Frey, 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. The research team then analyzed N-acetylaspartate (NAA) levels, a chemical associated with neuronal health. The researchers found that NAA values for the reattachment and transplant patients were similar to levels of amputees and significantly lower than the healthy control group.
Frey noted, “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 studied, the researchers said that the results should be interpreted with caution until more work is completed.
No comments:
Post a Comment