People with a curious condition that causes
them to apply make-up on only one side of their face, or ignore food on half of
their plate, are helping scientists to understand stroke recovery.
People
with a curious condition that causes them to apply make-up on only one side of
their face, or ignore food on half of their plate, are playing a new role in
understanding stroke recovery.
Ina new
publication in The Journal of Neuroscience, researchers from the
Queensland Brain Institute (QBI) have found that people with the condition, a
subset of the stroke called ‘unilateral spatial neglect,’ tend to have the
worst recovery outcomes in regaining lost functioning in their bodies.
This
finding has led the team to believe that attention may have an important impact
on recovering successfully.
Unilateral
spatial neglect is typically caused by strokes on the right hand side of the
brain and manifests in patients ignoring the left side of their body.
People
with the condition may ignore food on the left hand side of their plate or, if
asked to draw a clock, squash all 12 numbers into the right side of the clock
face, leaving the other side blank.
They
may also fail to shave, or to put make-up on the left side of their faces and.
In severe cases, they behave as though the left side of their world does not
exist.
“We
know that brain plasticity plays a critical role in recovering from stroke,”
said Professor Jason Mattingley of The University of Queensland, a senior
author on the paper.
“The
fact that people with spatial neglect tend to have poorer recovery of motor
function suggested to us that attention may be important for guiding plasticity
following stroke.”
Current
research being undertaken by the Mattingley laboratory is exploring this link.
Volunteers first undergo a magnetic resonance imaging (MRI) scan, which
provides researchers with a three-dimensional picture of the brain.
The MRI
scan allows researchers to guide a transcranial magnetic stimulation (TMS) coil
into position upon a volunteer’s scalp, which induces a small electrical
current in the underlying brain tissue, causing it to become more active.
In this
study, the researchers specifically target a part of the motor cortex that
controls the thumb muscle in the left hand.
“By
adjusting the type of brain stimulation delivered we can artificially induce
short-term changes that resemble naturally-occurring plasticity,” explained Dr.
Marc Kamke, Research Fellow at QBI.
But
what the researchers have found is that the effects of stimulation upon a
brain’s plasticity are dependent on attention.
“When
we ask people to undertake a visual task that is irrelevant to the brain
stimulation, but that demands a great deal of their attention, we observe a
reduction in plasticity,” Kamke explains.
When
the task does not require much attention, however, the brain’s plastic response
is apparent.
While
practical applications remain several steps away, the team hopes that this
knowledge may help researchers develop more effective strategies for physical
therapy after stroke.
The
article can be found at: Kamke MR et al. (2012) Visual Attentional Load
Influences Plasticity in the Human Motor Cortex.
——
Source: Queensland Brain Institute.
No comments:
Post a Comment