Language is a complex cognitive function, requiring several areas of the brain to oversee the motor function of speech and the articulation of intelligible sentences, as well as nuances such as the ability to comprehend irony or non-literal concepts. A traumatic brain injury during childhood can significantly impact language ability, with impairments sometimes being delayed by developmental milestones.
The correlation of brain areas to language impairment after pediatric traumatic brain injury is still not well understood. A recent study used diffusion-weighted tractography (a type of scan) to determine that injury to the white matter tracts in the brain (namely the corpus callosum, arcuate fasciculus, and uncinate fasciculus) predicts poor language outcome over the long-term. The language impairments especially involved sentence formation and semantic association. When both the corpus callosum and the left arcuate fasciculus were injured, the "dual blow" created the most serious language impairments.
Persisting language deficits after pediatric traumatic brain injury may therefore be related to diffuse axonal injury, which can affect multiple white matter tracts in the brain.
Liegeois FJ, Mahony K, Connelly A, et al. Pediatric traumatic brain injury: Language outcomes and their relationship to the arcuate fasciculus. Brain & Language. (December 2013).