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

New ALS therapy in clinical trials—drug extends survival, reverses some neuromuscular damage in animals

July 16, 2018
About 20,000 people in the United States are living with amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease. The invariably fatal disease kills the nerve cells that control walking, eating and breathing. ...

Convergence of synaptic signals is mediated by a protein critical for learning and memory

July 16, 2018
Inside the brain, is a complex symphony of perfectly coordinated signaling. Hundreds of different molecules amplify, modify and carry information from tiny synaptic compartments all the way through the entire length of a ...

Synapse-specific plasticity governs the identity of overlapping memory traces

July 16, 2018
Memories are formed through long-term changes in synaptic efficacy, a process known as synaptic plasticity, and are stored in the brain in specific neuronal ensembles called engram cells, which are activated during corresponding ...

'Concussion pill' shows promise in pre-clinical pilot study

July 16, 2018
In 2016, funded by a $16 million grant from Scythian, the multidisciplinary Miller School team embarked on a five-year study to examine the effects of combining CBD (a cannabinoid derivative of hemp) with an NMDA antagonist ...

Fetal gene therapy prevents fatal neurodegenerative disease

July 16, 2018
A fatal neurodegenerative condition known as Gaucher disease can be prevented in mice following fetal gene therapy, finds a new study led by UCL, the KK Women's and Children's Hospital and National University Health System ...

Rehabilitating the mind could improve outcomes after spinal cord injury

July 16, 2018
A study led by Heriot-Watt University has explored how individuals with spinal cord injuries perceive the space around them. The findings suggest additions are needed to the rehabilitation programmes adopted post-injury to ...

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.