First-of-its-kind study shows how hand amputation, reattachment affect brain

May 24, 2017 by Maria Platz, University of Missouri-Columbia
MU researchers found evidence of specific neurochemical changes associated with lower neuronal health in specific brain regions. Credit: University of Missouri-Columbia

When a person loses a hand to amputation, nerves that control sensation and movement are severed, causing dramatic changes in areas of the brain that controlled these functions. As a result, areas of the brain devoted to the missing hand take on other functions. Now, 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 Carmen M. Cirstea, M.D., Ph.D., research assistant professor of Physical Medicine and Rehabilitation and lead author of the study. "Using a noninvasive approach known as (MRS) to examine areas of the brain previously involved with , we observed the types of changes taking place at the neurochemical level after amputation, transplantation or reattachment."

Cirstea, with co-author Scott Frey, Ph.D., 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 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.

"Previous research has found substantial reorganizational changes in the brain following limb injuries that decrease sensory and motor stimulation following limb injuries," Frey said. "These findings show that after surgical repairs, the effects of nerve injuries on the mature 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 (5), the researchers said that the results should be interpreted with caution until more work is completed.

The study, "Magnetic Resonance Spectroscopy of Current Hand Amputees Reveals Evidence for Neuronal-level Changes in Former Sensorimotor Cortex," was published in the Journal of Neurophysiology.

Explore further: Cortical nerve function in former amputees remains poor decades after reconstructive surgery

More information: Carmen M. Cirstea et al, Magnetic resonance spectroscopy of current hand amputees reveals evidence for neuronal-level changes in former sensorimotor cortex, Journal of Neurophysiology (2017). DOI: 10.1152/jn.00329.2016

Related Stories

Cortical nerve function in former amputees remains poor decades after reconstructive surgery

April 12, 2017
Researchers have found that the nerve cells (neurons) controlling sensation and movement of the hands show injury-induced changes for years after hand amputation, reattachment or transplant. The small study, the first of ...

Study suggests new rehabilitation methods for amputees and stroke patients

March 12, 2014
When use of a dominant hand is lost by amputation or stroke, a patient is forced to compensate by using the nondominant hand exclusively for precision tasks like writing or drawing. Presently, the behavioral and neurological ...

Amputees' brains remember missing hands even years later

August 30, 2016
Our brains have a detailed picture of our hands and fingers, and that persists even decades after an amputation, Oxford University researchers have found. The finding could have implications for the control of next generation ...

'Unfussy' brain finds ways of coping with loss of a hand

January 8, 2015
People born without one hand, who are still able to use both limbs well in otherwise two-handed tasks, are likely to show brain activity which resembles that of people with two hands, an Oxford University study has found.

Cause of phantom limb pain in amputees, and potential treatment, identified

October 27, 2016
Researchers have discovered that a 'reorganisation' of the wiring of the brain is the underlying cause of phantom limb pain, which occurs in the vast majority of individuals who have had limbs amputated, and a potential method ...

Recommended for you

Study of protein 'trafficker' provides insight into autism and other brain disorders

September 22, 2018
In the brain, as in business, connections are everything. To maintain cellular associates, the outer surface of a neuron, its membrane, must express particular proteins—proverbial hands that reach out and greet nearby cells. ...

Breast milk may be best for premature babies' brain development

September 21, 2018
Babies born before their due date show better brain development when fed breast milk rather than formula, a study has found.

Early warning sign of psychosis detected

September 21, 2018
Brains of people at risk of psychosis exhibit a pattern that can help predict whether they will go on to develop full-fledged schizophrenia, a new Yale-led study shows. The findings could help doctors begin early intervention ...

White matter repair and traumatic brain injury

September 20, 2018
Traumatic brain injury (TBI) is a leading cause of death and disability in the U.S., contributing to about 30 percent of all injury deaths, according to the CDC. TBI causes damage to both white and gray matter in the brain, ...

Genomic dark matter activity connects Parkinson's and psychiatric diseases

September 20, 2018
Dopamine neurons are located in the midbrain, but their tendril-like axons can branch far into the higher cortical areas, influencing how we move and how we feel. New genetic evidence has revealed that these specialized cells ...

Gut branches of vagus nerve essential components of brain's reward and motivation system

September 20, 2018
A novel gut-to-brain neural circuit establishes the vagus nerve as an essential component of the brain system that regulates reward and motivation, according to research conducted at the Icahn School of Medicine at Mount ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.