Abstract
Objectives: Language is one of the core attributes of human development. Impaired or delayed language development (i.e., developmental language disorder: DLD) is a highly prevalent condition; however, its underlying etiopathogenetic causes are not fully elucidated. The possible role of multisensory integration (MSI) may be proposed. The aim of this pilot interventional study was to assess the effect of an individualized vestibular exercise training program regarding the processes that rely on multisensory integration in DLD. Methods: Children aged between 5 and 12 years with DLD and their age-matched neurotypical controls were included. Following informed consent, a baseline assessment (primitive reflexes, postural control, receptive language performance) was conducted. Next, a 26 week-long exercise program rich in vestibular stimuli was implemented in the DLD group. At 26-week follow-up, both groups were reassessed. Results: Compared to baseline, the primitive reflex profile significantly improved in the DLD group. Scores for dynamic postural control also improved (score of 0.25 IQR 0-1 at baseline vs. 2 IQR 1-2 at follow-up; p < 0.001). Age-standardized scores for receptive grammar (score of 79.5 IQR 71.5-89.5 at baseline, 87 IQR 66-103 at follow-up; p = 0.03) were also improved. When two-way comparisons using the mixed-effects models were made, improvement in the DLD group was evident when compared to baseline levels and to the control group at follow-up. Conclusions: Based on these results, the possible interplay between multisensory and sensorimotor integration and integration of primitive reflexes is proposed, with vestibular stimulation contributing to the cortical input that may underlie the maturation of the areas dedicated to multisensory processes.