Symptoms previously considered “defective” in patients with language disorder are actually adaptive

BOSTON – Individuals with a language disorder called nonfluent aphasia—which may result from a stroke, head injury, or neurodegeneration find it difficult to speak in complex sentences, and they have various word-level abnormalities, including using fewer verbs and fewer function words such as pronouns and prepositions. Experts have presumed that these symptoms result from a brain deficit in language processing, but a new study led by investigators at Massachusetts General Hospital (MGH) refutes this theory. The findings, which are published in the Annals of Neurology, suggest that the features of nonfluent aphasia are part of a compensation strategy to sustain sentence information.

After experiencing a brain injury or lesion, an individual may develop symptoms that are directly caused by the injury itself or are the result of the brain’s adaptive response to deficits from the injury. Differentiating adaptive from defective symptoms can help clinicians avoid targeting the wrong symptoms in rehabilitative care and better understand the mechanisms behind a patient’s condition.

To determine the basis of the symptoms of nonfluent aphasia, investigators analyzed spoken and written samples from individuals with and without the condition. Participants were asked to look at a drawing of a family at a picnic and describe it using as many complete sentences as possible.

Using methods including artificial intelligence, the researchers found that because patients with nonfluent aphasia have difficulty using complex sentences, they compensate by choosing semantically richer and more informative words in their structurally simple sentences to sustain sentence information.

“This research offers a foundational shift in how we interpret symptoms of nonfluent aphasia,” says lead author Neguine Rezaii, MD, an assistant in Neurology at MGH and an instructor in Neurology at Harvard Medical School. The work also indicates a need for revisions in the treatment of nonfluent aphasia to place the focus on promoting the use of informative words. “The goal would be to strengthen the same adaptive strategy patients are already using,” says Rezaai. “Artificial intelligence can help identify most informative words given the preceding context. These word suggestions might help patients be even more informative and also gain more confidence in their word selection.”

Additional co-authors include James Michaelov, PhD, Sylvia Josephy-Hernandez, MD, Boyu Ren, PhD, Daisy Hochberg, MS, Megan Quimby, MS, and Bradford C. Dickerson, MD.

This work was funded by the National Institutes of Health and the Tommy Rickles Chair in Primary Progressive Aphasia Research.

 

About the Massachusetts General Hospital

Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The Mass General Research Institute conducts the largest hospital-based research program in the nation, with annual research operations of more than $1 billion and comprises more than 9,500 researchers working across more than 30 institutes, centers and departments. In July 2022, Mass General was named #8 in the U.S. News & World Report list of "America’s Best Hospitals." MGH is a founding member of the Mass General Brigham healthcare system.

 

 

Would it be possible to add a bit of information on what such treatments might involve? Or perhaps explain what you mean here… I thought that patients already use more informative words in their shorter sentences…so how would promoting the use of informative words help? Thanks!