Affiliations: Bobby R. Alford Department of Otolaryngology – Head and Neck Surgery, Center for Balance Disorders, Baylor College of Medicine, Houston, TX, USA
Correspondence:
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Corresponding author: Helen Cohen Ed.D., O.T.R., Baylor College of Medicine, Department of Otolaryngology, One Baylor Plaza, Houston, TX 77030, USA. Tel.: +1 713 798 6336; Fax: +1 713 798 8658; E-mail: [email protected]
Abstract: The objective of this study was to assess the effects of different methods of sternocleidomastoid muscle (SCM) activation on vestibular evoked myogenic potentials (VEMP). Forty normal volunteers were tested using three different methods of SCM activation: sitting with the head turned away from the test ear (SIT), supine with the head held straight up (SHU), and supine with the head held up and turned away from the test ear (SHT). Dependent measures were latency, and amplitude. Head and body position significantly affected the amplitude of the VEMP, but had no significant effect on latency. Testing subjects in the supine position with the head up and turned toward the non-test ear yielded the most robust amplitude response and sternocleidomastoid EMG activity. When amplitude measures where corrected according to tonic electromyographic (EMG) activity no significant difference was noted between the three different test positions. The increased amplitude in the supine with head turned position can be directly attributed to increased tonic SCM EMG activity.
