title: Ocular vestibular evoked myogenic potentials are abnormal in internuclear ophthalmoplegia.
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.
  
  
  CONCLUSIONS
  Ocular VEMPs are often abnormal in patients with multiple sclerosis who have an INO, while cVEMPs are usually normal.
  
  
  CONCLUSIONS
  Ocular VEMPs provide a new, non-invasive method for examining central vestibular pathways in humans and are sensitive to lesions of the MLF.
authors.affiliation: Prince of Wales Clinical School and Neuroscience Research Australia, University of New South Wales, Randwick, Sydney, NSW 2031, Australia. s.rosengren@unsw.edu.au
authors.forename: S M
authors.initials: SM
authors.lastname: Rosengren
authors.forename: J G
authors.initials: JG
authors.lastname: Colebatch
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000293:Adolescent; D000328:Adult; D004576:Electromyography / Q000379:methods; D005260:Female; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000473:pathology* / Q000503:physiopathology*; D009801:Oculomotor Muscles / Q000503:physiopathology*; D011930:Reaction Time / Q000502:physiology; D058585:Vestibular Evoked Myogenic Potentials / Q000502:physiology*