A new study links stuttering to changes in brain circuits that control speech production, as well as circuits that support attention and emotion.
For the study, researchers at Children’s Hospital Los Angeles (CHLA) used proton magnetic resonance spectroscopy (MRS) to look at brain regions in adults and children who stutter.
Consistent with past functional MRI studies, the findings demonstrate neuro-metabolite alterations across the brain, according to the researchers.
Developmental stuttering is a neuropsychiatric condition. Its origins in the brain are only partly known.
To measure an index of neural density related to stuttering in circuits and brain regions suspected to be affected, the scientists performed proton shift imaging of the brain in 47 children and 47 adults. The study included subjects with and without stuttering.
The research team found that affected brain regions included major nodes of the so-called Bohland speech-production network (associated with the regulation of motor activity); the default-mode network (involved in the regulation of attention); and the emotional-memory network (responsible for regulating emotion.)
“That stuttering is related to speech and language-based brain circuits seems clear,” said Bradley S. Peterson, M.D., director of the Institute for the Developing Mind at CHLA, and director of the Division of Child and Adolescent Psychiatry at the Keck School of Medicine of the University of Southern California.
“Attention-regulating portions of the brain are related to control circuits that are important in governing behavior. People with changes here are more likely to stutter and have more severe stuttering. And emotions like anxiety and stress also tend to make stuttering worse, likely because this network interacts with language and attention control circuits.”
The initial MRS study of stuttering confirmed that disturbances in neuronal or membrane metabolism contribute to the development of stuttering, he noted.
Looking at a combination of children and adults to detect the effects of stuttering, independent of life-stage, revealed differences between children and adults within both the stuttering and control samples. This suggests different metabolic profiles in children versus adults who stutter, according to the researchers. Few sex-specific effects of stuttering on brain metabolites were observed, they added.
The study was published in the Journal of the American Medical Association (JAMA).
Source: Children’s Hospital Los Angeles