It’s hard to adequately describe the value of being able to communicate and its role in expressing a person’s humanity, which is one reason researcher Leonardo Bonilha works so hard to help patients keep that ability.

With two studies recently published, researchers with the Language and Aphasia Clinic at the Medical University of South Carolina are looking into what happens in the brain when people lose the ability to communicate and, more importantly, how to use this information to help recovery.

Bonilha, a neurologist and researcher at MUSC, says the fact that these publications have come out within such a short time show the importance of this research and the strength of collaborations within the clinic and in research. One example of that collaboration was the study published in the journal Scientific Reports that explored the differences in recovery for people who experience language disturbances or aphasia after a stroke. About 60 to 70 percent of survivors recover their ability to produce language within six months. The other 30 to 40 percent of stroke patients, however, suffer permanent aphasia.

It is still not well understood why this happens, he said. Currently, all doctors can do is give an educated guess based largely on the age of the person and the size and location of the stroke lesion, but the predictions can be frustratingly inaccurate. Some researchers think variations in long term aphasia severity may be caused by an undetected fragmentation or disorganization of brain networks that disrupts the transfer of information in areas that may be far from the lesion itself.

To investigate this theory, Bonilha and other MUSC researchers, working in close collaboration with a team led by Fridriksson, PhD, mapped entire brain networks and assessed connectivity in 90 people who had suffered a left hemisphere stroke.

Bonilha said the study demonstrates that the preservation of brain wiring after a stroke is associated with less severe speech problems. Even though strokes tend to occur in one localized brain region, the damage can extend far beyond the stroke area by disconnecting areas that are not directly affected by the stroke.

“In this study, we observed that, by measuring how much these disconnections can alter the normal wiring pattern of the brain, we can explain how impaired someone is in the long run after the strokes. The reasons why someone does not recover after a stroke are not fully understood, and this study directly addresses this problem by demonstrating that the wiring of the remaining brain is one important factor for recovery.”

Another study is the article published online on June 19 by the Annals of Neurology journal, which explored the ability of the residual language network in the brain to rebuild itself after a stroke. This characteristic, called structural plasticity, is directly related to how much benefit a patient might receive from speech therapy.

Bonilha says the speech therapy study demonstrated that the parts of the brain that are preserved after a stroke do change in terms of their structure. They “rewire” in response to speech therapy, and this change in the brain is associated with speech improvement.