Corticobulbar Tract Injury, Oromotor Impairment and Language Plasticity in Adolescents Born Preterm

Area of Science:

• Neuroscience
• Developmental Pediatrics
• Speech-Language Pathology

Background:

• Children born preterm (<33 weeks' gestation) face risks for oromotor control impairments.
• These deficits can impact early feeding and speech development, persisting into later life.

Purpose of the Study:

• To identify neuroanatomical markers of persistent oromotor deficits in very preterm adolescents using diffusion-weighted imaging (DWI) tractography.
• To investigate evidence of compensatory neuroplasticity through functional MRI (fMRI) during a language task.

Main Methods:

• A cross-sectional study involving 36 adolescents born very preterm.
• Diffusion-weighted imaging (DWI) tractography analyzed corticospinal and corticobulbar tract microstructure (fractional anisotropy, FA).
• Functional MRI (fMRI) assessed brain activity during a language production task.

Main Results:

• 31% of very preterm adolescents exhibited persistent oromotor control difficulties without formal speech-sound disorder diagnoses.
• The oromotor-impaired group showed reduced FA in the left corticobulbar tract.
• Greater recruitment of right hemisphere language regions was observed in the impaired group during fMRI.

Conclusions:

• Early corticobulbar tract injury in preterm infants can lead to persistent, subclinical oromotor control deficits.
• Despite apparently normal speech, voluntary control of facial and oral structures may be subtly impaired.
• Cerebral plasticity, particularly right hemisphere language area recruitment, may ameliorate early speech problems.