Figure 10.

Recordings of ocular vestibular-evoked myogenic potentials (oVEMPs) (A,C) and cervical vestibular-evoked myogenic potentials (cVEMPs) (B,D) to 500 Hz bone-conducted vibration (BCV) from a healthy subject (A,B) and a patient with semicircular canal dehiscence (SCD) (C,D). In each record, the stimulus onset occurred at time 0. In the healthy subject, BCV at the midline of forehead at the hairline (Fz) causes symmetric oVEMP beneath both eyes, with approximately equal amplitude oVEMP n10 components (arrowheads). By contrast, the same Fz stimulus causes an asymmetric n10 component of the oVEMP response in the patient: the oVEMP n10 recorded from beneath the contralesional eye is much larger than the oVEMP n10 recorded from beneath the ipsilesional eye, and is also much larger than seen in the healthy subject. In response to BCV at Fz, both subjects show clear cVEMP p13–n23 [arrowheads in (B,D)]. The response in the ipsilesional sternocleidomastoid muscle (SCM) in the patient is larger than in the patient’s contralesional SCM, but the asymmetry is not as great as in the same patient’s oVEMP traces. The cVEMP responses of the normal subject are more symmetrical than in the SCD patient. Reprinted by permission from Wolters Kluwer Health, Inc.: Manzari et al. (94), © 2012.