Impact of oral motor task training on corticomotor pathways and diadochokinetic rates in young healthy participants

Abstract

Background: Studies addressing the training-induced neuroplasticity and interrelationships of the lip, masseter, and tongue motor representations in the human motor cortex using single syllable repetition are lacking. Objective: This study investigated the impact of a repeated training in a novel PaTaKa diadochokinetic (DDK) orofacial motor task (OMT) on corticomotor control of the lips, masseter, and tongue muscles in young healthy participants. Methods: A total of 22 young healthy volunteers performed 3 consecutive days of training in an OMT. Transcranial magnetic stimulation was applied to elicit motor evoked potentials (MEPs) from the lip, masseter, tongue, and first dorsal interosseous (FDI, internal control) muscles. MEPs were assessed by stimulus–response curves and corticomotor mapping at baseline and after OMT. The DDK rate from PaTaKa single syllable repetition and numeric rating scale (NRS) scores were also obtained at baseline and immediately after each OMT. Repeated-measures analysis of variance was used to detect differences at a significance level of 5%. Results: There was a significant effect of OMT and stimulus intensity on the lips, masseter, and tongue MEPs compared to baseline (p.05). OMT increased corticomotor topographic maps area (p