Gray matter volume and metabolism in stuttering (Boley et al., 2021)

Purpose: The biological mechanisms underlying developmental stuttering remain unclear. In a previous investigation, we showed that there is significant spatialcorrespondence between regional gray matter structural anomalies and the expression of genes linked to energy metabolism. In the current study, we sought to further examine the relationship between structural anomalies in the brain in children with persistent stuttering and brain regional energy metabolism.

Method: High-resolution structural MRI scans were acquired from 26 persistent stuttering and 44 typically developing children. Voxel-based morphometry was used to quantify the between-group gray matter volume (GMV) differences across the whole brain. Group differences in GMV were then compared with published values for the pattern of glucose metabolism measured via F¹⁸ fluorodeoxyglucose uptake in the brains of 29 healthy volunteers using positron emission tomography.

Results: A significant positive correlation between GMV differences and F¹⁸ fluorodeoxyglucose uptake was found in the left hemisphere (ρ = .36, p < .01), where speech-motor and language processing are typically localized. No such correlation was observed in the right hemisphere (ρ = .05, p = .70).

Conclusions: Corroborating our previous gene expression studies, the results of the current study suggest a potential connection between energy metabolism and stuttering. Brain regions with high energy utilization may be particularly vulnerable to anatomical changes associated with stuttering. Such changes may be further exacerbated when there are sharp increases in brain energy utilization, which coincides with the developmental period of rapid speech/language acquisition and the onset of stuttering during childhood.

Supplemental Material S1. Participants’ sex and age at each scan.

Supplemental Material S2. Gray matter volume (GMV) differences in terms of absolute t-statistics (|t-stat|) and ¹⁸F-fluorodeoxyglucose (FDG) uptake (µmol/g/min) in each region.

Boley, N., Patil, S., Garnett, E. O., Li, H., Chugani, D. C., Chang, S.-E., & Chow, H. M. (2021). Association between gray matter volume variations and energy utilization in the brain: Implications for developmental stuttering. Journal of Speech, Language, and Hearing Research. Advance online publication. https://doi.org/10.1044/2020_JSLHR-20-00325

Publisher Note: This article is part of the Special Issue: Select Papers From the 2020 Conference on Motor Speech.