Normal values for cervical and ocular vestibular-evoked myogenic potentials using EMG scaling: effect of body position and electrode montage
Navid Shahnaz, Eytan A. David
Abstract
BACKGROUND: The clinical utility of cervical and ocular vestibular-evoked myogenic potential (cVEMP and oVEMP) is limited by variability of testing protocols and a dearth of normative data using contemporary methods for amplitude scaling. AIMS/OBJECTIVES: To investigate the effect of body position and electrode montage on VEMP responses and to establish normative values. MATERIAL AND METHODS: This is a repeated measures study of 44 healthy young adult subjects (22 men and 22 women). RESULTS: The highest response rate (99%) for cVEMP was achieved in the supine position with the head elevated and turned. For oVEMP, the highest response rate (90%) was achieved using nasal alar electrode montage with the subject in a sitting position. Scaled peak-to-peak amplitude was higher in males than in females for both cVEMP and oVEMP. CONCLUSION: Normative data for 44 young healthy adults was successfully collected for two body positions for cVEMP and two head positions and two electrode montages for oVEMP. SIGNIFICANCE: Our findings describe VEMP protocols that efficiently detect VEMP responses, and we provide normative VEMP response data for young healthy subjects. We describe a potential difference in response between males and females, which may be clinically important.