Vestibular Evoked Myogenic Potentials in Cervical Myofascial Pain Syndrome.

Cervical myofascial pain syndrome with dizziness (CMPS-D) has always faced the challenges of evaluation, diagnosis, and etiology. Vestibular-evoked myogenic potentials (VEMPs) are applicable to evaluate the functions of the vestibular system, especially the saccule. The Sound evoked triceps myogenic potentials (SETMPs) have different anatomical efferent connections from Sternocleidomastoid (SCM)-VEMPs. The present study aimed to evaluate the SETMPs and SCMVEMPs in CMPS-D group and compare the results with the control group. We tested 15 participants with CMPS-D with 15 participants in the control group using SCMVEMP and SETMP tests. All participants had normal hearing and vestibular functions. The SCMVEMP response was absent in 4 of 15 patients with CMPS-D, and the mean response CMPS-D group was significantly lower than the control group. There were the SETMP and SCMVEMP responses in all participants in the control group. In CMPS-D subjects with false absent SCMVEMP response, SETMP tests are suitable alternatives for the saccule evaluation, and diminished SCMVEMP in the CMPS-D subjects may not necessarily mean the saccular injury. Furthermore, the involvement of spinal cord pathways is not a cause of dizziness in CMPS-D patients.