In VEMP testing, which muscle is typically monitored for cVEMP?

• A. Ipsilateral sternocleidomastoid muscle
• B. Contralateral trapezius muscle
• C. Ipsilateral masseter muscle
• D. Occipitofrontalis muscle

Answer: (A)

In cVEMP, the reflex is best recorded from the neck’s sternocleidomastoid muscle on the same side as the stimulus because this muscle reliably reflects the vestibulocollic pathway’s inhibitory response. When a sound stimulus activates the vestibular system, it triggers a brief reflex that modulates activity in the ipsilateral SCM. Having the patient consciously contract that same SCM (for example, by turning the head to the opposite shoulder) creates a stable, measurable EMG signal, allowing a clear cVEMP waveform to be captured. The other muscles listed are not standard monitoring sites for this response; they do not provide the same robust, ipsilateral vestibulo-collic recording needed for cVEMP.