Usefulness of masseter vestibular evoked myogenic potentials in identifying brainstem dysfunction among individuals with multiple sclerosis.

OBJECTIVE:The present study aimed to investigate the findings of cervical, ocular and masseter vestibular evoked myogenic potentials (cVEMP, oVEMP and mVEMP) among Multiple sclerosis (MS) and correlate with clinical and MRI findings. DESIGN:Standard group comparison research design. STUDY SAMPLE:Individuals with relapsing-remitting MS (n = 45) and age-sex-matched controls (n = 45) were the participants. All of them underwent case history, neurological examination, cVEMP, oVEMP and mVEMP testing. MRI was obtained only for MS participants. RESULTS:Abnormal result on at least one vestibular evoked myogenic potential (VEMP) sub-type was evidenced in 95.56% of participants whereas, unilateral or bilateral abnormal result on all three VEMP sub-types was observed in 60% of participants. The mVEMP abnormality was higher (82.22%) than cVEMP (75.56%) and oVEMP (75.56%) abnormalities but the differences were not significant (p > 0.05). There was no significant association of VEMP abnormalities with the presence of the brainstem symptoms, the brainstem signs, or the MRI lesions (p > 0.05). In the MS group, 38% had normal brainstem MRI; however, mVEMP, cVEMP and oVEMP abnormalities were evidenced in 82.4%, 64.7% and 52.94%, respectively. CONCLUSIONS:Among the three VEMP sub-types, mVEMP appears to be of greater value in identifying silent brainstem dysfunction undetected by clinical and MRI findings in the MS population.