Differentiating cerebellar and brainstem lesions with ocular vestibular-evoked myogenic potential test

Abstract

This study applied both ocular vestibular-evoked myogenic potential (oVEMP) and cervical VEMP (cVEMP) tests in patients with cerebellar disorders to determine whether VEMP test can differentiate between cerebellar and brainstem lesions. A total of 12 patients with cerebellar disorder, including extended cerebellar lesion (involving the brainstem) in 8 and localized cerebellar lesion (excluding the brainstem) in 4, were enrolled in this study. All patients underwent caloric, visual suppression, and oVEMP and cVEMP tests via bone-conducted vibration stimuli. The abnormal rates for the caloric, visual suppression, and oVEMP and cVEMP tests were 62, 83, 88 and 75% in patients with extended cerebellar lesion and 0, 25, 0 and 0% in those with localized cerebellar lesion, respectively. The rate of abnormal oVEMP results significantly differed between the two groups, but caloric, visual suppression and cVEMP test results did not differ. In another ten healthy subjects, characteristic parameters of oVEMPs obtained under light and dark conditions did not significantly differ. In conclusion, ocular VEMP test can differentiate between cerebellar and brainstem lesions. Abnormal oVEMPs in patients with cerebellar disorder may indicate adjacent brainstem involvement.

Characteristics and clinical applications of ocular vestibular evoked myogenic potentials

“…Cerebellar lesions affecting the brainstem, however, revealed abnormal oVEMP and cVEMP responses in 88 and 75%, respectively (Su and Young, 2011). It was only the rate of abnormal oVEMPs which significantly differed between the two groups, indicating that oVEMPs may help to differentiate between cerebellar and brainstem lesions.…”

Vestibular-evoked myogenic potentials in central vestibular disorders

“…Lesions of the nodulus or uvula may affect the otolith-ocular reflexes and oVEMPs [30]. A study found absent oVEMPs in patients with cerebellar lesions extending into the brainstem, but normal responses in patients with isolated cerebellar lesions [39]. Abnormal VEMPs in isolated cerebellar lesions suggest a 'modulatory role' of the cerebellum on the otolithic function, or some cases of technically abnormal VEMPs, or perhaps the lesions larger than they appear on imaging.…”

Cervical Vestibular Evoked Myogenic Potentials in Cerebellar Lesions

“…Reports about cVEMPs in central nervous system lesions are scarce, and our experience is dominated by peripheral vestibular system disorders such as Ménière's disease, vestibular neuritis, superior semicircular canal dehiscence, and other inner ear perilymphatic fistulas (6). Our experience in patients with cerebellar lesions is evolving, with only a few cases published (7,8), and more illustrative cases are required. Other studies involving lesions in the posterior fossa have focused on the brainstem either alone or together with the cerebellum (9Y15).…”