Vestibular System Eletrophysiology: An Analysis of the Relationship between Hearing and Movement.

Knowledge about the positive effects that music and dance bring, in its various forms, to the healthy human brain, is important not only in the context of basic neuroscience but may also strongly affect practices in neurorehabilitation.  To verify the relationship between hearing and movement and, specifically, to analyze the interference of professional dance practice and formal musical training in the magnitude of the vestibule-cervical and vestibular reflexes.  The sample consisted of 92 subjects, aged between 18 and 35 years old, 31 professional musicians, 31 ballet dancers, and 30 control subjects. Only subjects with normal hearing sensitivity were included. Cervical vestibular evoked myogenic potential (cVEMP) was recorded in the sternocleidomastoid muscle, and ocular vestibular evoked myogenic potential (oVEMP) was recorded in the lower oblique muscle of the eye, using tone-bursts (500Hz). Analysis of variance (ANOVA) or Kruskall-Wallis tests were performed.  The cVEMP presented earlier and higher amplitude waves when recorded in the group of dancers, with a significant difference between all tested groups for latency and amplitude of the N23 wave; the comparison was restricted between dancers and control groups, with no difference between ballet dancers and musicians. The N1 wave of the oVEMP presented lower latencies in dancers than in musicians and controls ( = 0.001). No significant differences were found between the groups for the P1 wave.  Greater magnitudes of vestibule-cervical reflex responses and faster vestibule-ocular reflex responses were observed in dancers. Dance practice provides greater development of the vestibular system, but musical training also contributes to the magnitude of these responses.