Measuring neck structures in relation to vestibular evoked myogenic potentials

Objective: This study examined whether neck length or thickness influences vestibular evoked myogenic potential (VEMP) responses. Methods: Twenty healthy children and 20 healthy adults underwent VEMP testing. Two reference points were selected for measuring neck length. Maximum thickness of the subcutaneous tissue and the sternocleidomastoid muscle was measured by ultrasonographic examination. Results: The mean latencies of peaks p13 and n23 in 20 healthy children were significantly earlier than those in healthy adults. Neck length significantly related to p13 latency in children, but not in adults. In contrast, corrected amplitudes did not differ significantly between children and adults. Ultrasonography guided measurement of the subcutaneous thickness in adults associated negatively with raw amplitude, but not with corrected amplitude. Conclusions: Vestibular evoked myogenic potential latencies correlated positively to neck length in all subjects (children and adults), while raw amplitudes of VEMPs in adults correlated negatively with subcutaneous thickness. No correlation between neck thickness and corrected amplitude was observed. Significance: Structural differences affecting latencies and raw amplitudes of VEMP responses should be considered when interpreting VEMP parameters. (c) 2007 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.