How the brain repairs stuttering

TLDR

Stuttering is a neurodevelopmental disorder linked to left inferior frontal structural anomalies, and while children often recover, rare cases of spontaneous adult recovery illustrate optimal brain repair beyond typical developmental windows. The study investigates how spontaneous adult recovery differs from therapy‑induced assisted recovery and compensatory attempts in persistent stutterers. The authors compare spontaneous recovery with therapy‑induced assisted recovery and compensatory attempts in subjects who remain affected. Persistent stuttering involves contralateral brain region mobilization for compensation, whereas optimal repair is marked by activation of left BA 47/12 in the orbitofrontal cortex adjacent to a white matter anomaly that normalizes in recovered subjects, indicating that late repair follows contralateral and perianomalous reorganization principles.

Abstract

Stuttering is a neurodevelopmental disorder associated with left inferior frontal structural anomalies. While children often recover, stuttering may also spontaneously disappear much later after years of dysfluency. These rare cases of unassisted recovery in adulthood provide a model of optimal brain repair outside the classical windows of developmental plasticity. Here we explore what distinguishes this type of recovery from less optimal repair modes, i.e. therapy-induced assisted recovery and attempted compensation in subjects who are still affected. We show that persistent stuttering is associated with mobilization of brain regions contralateral to the structural anomalies for compensation attempt. In contrast, the only neural landmark of optimal repair is activation of the left BA 47/12 in the orbitofrontal cortex, adjacent to a region where a white matter anomaly is observed in persistent stutterers, but normalized in recovered subjects. These findings show that late repair of neurodevelopmental stuttering follows the principles of contralateral and perianomalous reorganization.