Contradicting evidence has recently been found that loss of speech through stoke in the right hemisphere of the brain can actually be recovered through the right side of the brain. This throws a spanner into the works of a long standing debate lasting more than 130 years, which had settled that the right hemisphere actually interferes with recovery. These findings most likely won’t end the debate immediately, however it will change treatment approaches in these cases.
“The study, published online in Brain, is the first to look at brain structure and grey matter volume when trying to understand how speech is recovered after a stroke. Results show that patients who have regained their voice have increased grey matter volume in the back of their right hemisphere — mirroring the location of one of the two left hemisphere speech areas.”
Around one third of people that survive post stroke experience a loss of speech and language. This disorder is known as aphasia and many of these people never fully regain their original communication abilities. This loss of speech occurs almost exclusively post-left hemisphere stroke with around 70 percent of people suffering these types of strokes having language difficulties post stroke.
“In a group of 32 left-hemisphere stroke survivors, the researchers determined whether increased grey matter volume in the right hemisphere related to better than expected speech abilities, given the individual features of each person’s stroke. The researchers enrolled an additional 30 individuals who had not experienced a stroke as a control group.”
The Researchers have determined through this study that stroke participants with more grey matter located in the back of the right hemisphere post-stroke have better than expected speech abilities after their stroke had more grey matter and those with less had worse speech. These same areas in the right hemisphere were found to be larger in the stroke survivors when compared to a normal control group indicating that a growth in these brain areas correlates to better speech production post-stroke.
“Turkeltaub, a member of the Center for Brain Plasticity and Recovery at Georgetown University and MedStar National Rehabilitation Network, and his colleagues are continuing their study, looking for areas that compensate for other aspects of language use, such as comprehension of speech. The speech center discovered by the team aids only in use of speech, not in understanding what is said to an affected stroke patient.”