Brain imaging identifies ways to help stroke patients regain speech
6 June 2008
An important breakthrough in understanding how the brain works could
help stroke patients to regain their speech. The UK charity Action
Medical Research has announced the results of the study as a "leap
forward in understanding".
The charity says that patients could benefit from this discovery
within the next three to five years. Up to one quarter of stroke
patients suffer from speech impairment of some degree. This can mean
difficulty with speaking and understanding what is said to them or even
trouble with reading and writing.
Some people find that, over time, their speech and understanding
improves but many more face an uphill struggle and some never recover;
even with therapy. Until now little was known about why some patients
make progress and some do not.
However, the Action Medical Research study has found that an answer
lies in the complex pathways that exist between the speech processing
areas on both sides of the brain.
Dr Jane Warren, who is based at Imperial College London, has used
specialised brain imaging techniques to identify areas of the brain that
are responsible for understanding speech and their connections with each
other. She has compared the way that nerve cells function in healthy
brains with those in patients who have been affected by stroke.
She has discovered that the brains of stroke sufferers may have to
'relearn' how to put together different types of information in order to
understand speech by using different parts of the brain to compensate
for damaged areas.
This may mean using new pathways so that one side of the brain can
talk to the other more effectively. Therefore, the better that these two
sides of the brain can co-operate then the better the chance of speech
recovery for the patient.
This breakthrough could assist the development of new drug and
therapy-based treatments to help patients to learn to speak again.
Dr Yolande Harley of Action Medical Research said, "This really is a
leap forward in understanding and is likely to be of benefit to patients
in the near future.
"Language difficulties can have a devastating, long term effect well
after someone has recovered from the shock and immediate physical impact
of having a stroke. Simple, everyday activities that we take for
granted; making a phone call, doing the shopping or simply holding a
conversation can become an ordeal.
"We all have those moments where a word is on the tip of our tongue
and know that frustration; imagine constantly feeling as if you are
struggling to find a word and that you cannot get across exactly what
you want to say. Then you may get a sense of the distress that a stroke
Dr Warren explains, "We've known for a long time that different parts
of the brain do different things; but one aspect of the brain that we
knew little about is how the brain creates and uses language systems.
"During the course of my work I have been able to find out what is
happening within the brain as stroke sufferers recover their speech.
Researchers already know that the front left hand side of the temporal
lobe seems to be concerned with finding meaning whilst the right hand
side is more concerned with inflection or pitch.
"When a stroke occurs, the blood supply to part of the brain is
blocked and, as a result, it doesn't get any oxygen or nutrients and
dies. My work has shown that the brain has a remarkable range of
alternative strategies to bypass these dead areas and resume normal
"There are several circuits that link different parts of the brain
together. Whether or not these circuits are damaged by a stroke is
likely to be a big factor in determining how well a stroke sufferer
"If we can find ways to get the left and right sides of the brain
co-operating with one another better after a stroke, we could improve
the chances of recovery. It's a very exciting result."