S M Rosengren1, J G Colebatch. 1. Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW 2031, Australia. s.rosengren@unsw.edu.au
Abstract
OBJECTIVE: The cervical vestibular evoked myogenic potential (cVEMP) is sensitive to lower brainstem lesions affecting the vestibulo-collic pathway. We wished to determine whether the ocular VEMP (oVEMP), a recently-described otolith-ocular reflex, is also abnormal in patients with brainstem lesions. We tested patients with internuclear ophthalmoplegia (INO), caused by a brainstem lesion in the medial longitudinal fasciculus (MLF), to investigate whether the oVEMP is abnormal in patients with a lesion of the otolith-ocular pathway. METHODS: We describe a patient who developed a right INO during his first episode of demyelination, and report results from 12 additional patients, most of whom had multiple sclerosis. All subjects were stimulated with air-conducted tone bursts. cVEMPs and oVEMPs were measured using surface electrodes placed over the neck and beneath the eyes. RESULTS: Overall, oVEMPs showed significantly more abnormalities (69%) than cVEMPs (8%). Ocular VEMPs were absent with stimulation of 13/26 ears, significantly delayed in 5/26 cases and normal in only 8/26 cases. CONCLUSION: Ocular VEMPs are often abnormal in patients with multiple sclerosis who have an INO, while cVEMPs are usually normal. SIGNIFICANCE: Ocular VEMPs provide a new, non-invasive method for examining central vestibular pathways in humans and are sensitive to lesions of the MLF.
OBJECTIVE: The cervical vestibular evoked myogenic potential (cVEMP) is sensitive to lower brainstem lesions affecting the vestibulo-collic pathway. We wished to determine whether the ocular VEMP (oVEMP), a recently-described otolith-ocular reflex, is also abnormal in patients with brainstem lesions. We tested patients with internuclear ophthalmoplegia (INO), caused by a brainstem lesion in the medial longitudinal fasciculus (MLF), to investigate whether the oVEMP is abnormal in patients with a lesion of the otolith-ocular pathway. METHODS: We describe a patient who developed a right INO during his first episode of demyelination, and report results from 12 additional patients, most of whom had multiple sclerosis. All subjects were stimulated with air-conducted tone bursts. cVEMPs and oVEMPs were measured using surface electrodes placed over the neck and beneath the eyes. RESULTS: Overall, oVEMPs showed significantly more abnormalities (69%) than cVEMPs (8%). Ocular VEMPs were absent with stimulation of 13/26 ears, significantly delayed in 5/26 cases and normal in only 8/26 cases. CONCLUSION: Ocular VEMPs are often abnormal in patients with multiple sclerosis who have an INO, while cVEMPs are usually normal. SIGNIFICANCE: Ocular VEMPs provide a new, non-invasive method for examining central vestibular pathways in humans and are sensitive to lesions of the MLF.
Authors: M M Iversen; D A Christensen; D L Parker; H A Holman; J Chen; M J Frerck; R D Rabbitt Journal: J Acoust Soc Am Date: 2017-06 Impact factor: 1.840
Authors: Rachael L Taylor; Catherine Blaivie; Andreas P Bom; Berit Holmeslet; Tony Pansell; Krister Brantberg; Miriam S Welgampola Journal: Exp Brain Res Date: 2014-01-25 Impact factor: 1.972