DOI: http://dx.doi.org/10.18203/issn.2454-5929.ijohns20173062

Vestibular nerve compression: role of auditory brainstem response and cervical vestibular evoked myogenic potentials

Deepa A. Valame, Geeta B. Gore

Abstract


The objective of the study was to evaluate the role of ABR and cVEMP in the diagnosis of vestibular compression syndrome (VCS) and to study the association of test results with the MRI findings. This is a case-report of four patients with VCS using case-study approach. Four patients with varying degrees of indentation of vestibulo-cochlear nerve by the anterior inferior cerebellar artery (AICA) loops were studied. Episodic rotatory vertigo was reported by three cases and two cases complained of tinnitus but the characteristic low-frequency ‘type-writer’ type of tinnitus was seen in only one. All cases showed evidence of retrocochlear pathology on ABR although two had normal peripheral hearing status. The cVEMP abnormalities noted were absence of cVEMP and reduced amplitude of cVEMP as compared to instrument-specific age-matched norms; only one case with no indentation of vestibulo-cochlear nerve had normal cVEMP tracings. Presence of AICA loops on the MRI by itself need not necessarily indicate vestibular compression syndrome. However when MRI excludes any other pathology in cases with symptoms such as unilateral sensorineural hearing loss, tinnitus, vertigo; vestibular compression could be the etiology. The likelihood of abnormal test findings is greater when the loop causes indentation of the nerve. 


Keywords


Vestibular Compression syndrome, cVEMP, AICA loops, ABR

Full Text:

PDF

References


Janetta PJ, Moller MB, Mollar AR. Disabling positional vertigo. N Eng J Med. 1984;310:1700–5.

McDermott A, Dutt S, Irving R, Pahor A, Chavda S. Anterior inferior cerebellar artery syndrome:fact or fiction? Clin Otolaryngol. 2003;28:75-80.

Yoo HS, Lee DW, Min HJ, Lee SH, Park CW. The Association of Anterior Inferior Cerebellar Artery in Internal Auditory Canal with Tinnitus and Hearing Loss. Korean J Audiol. 2011;15:67-71.

Gorrie A, Warren FM, Garza AN, Shelton C, Wiggins RH. Is there a correlation between vascular loops in the cerebellopontine angle and unexplained unilateral hearing loss? Otol Neurotol. 2010;31(1):48-52.

Moller AR. Vascular compression of cranial nerves:II:pathophysiology. Neurol Res. 1999;21:439-43.

Singh NK, Singh P, Usha M, Akshay M. Audio-vestibular findings in Vestibular Paroxysmia. Indian J Otol. 2013;19:82-4.

Applebaum EL, Valvassori GE. Auditory and vestibular system. Findings in patients with vascular loops in the internal auditory canal. Ann Otol Rhinol Laryngol. 1984;92(112):63-70.

MtCabe BF, Gantz BJ. Vascular loop as a cause of incapacitating dizziness. Am J Otol. 1989;10:117-20.

Schwaber MK, Whetsell WO. Cochleovestibular compression syndrome. II. Vestibular nerve histopathology and theory of pathophysiology. Laryngoscope. 1992;102:1030-6.

Clift JM, Wong RD, Carney GM, Stavinoha RC, Boyev KP. Radiographic analysis of cochlear nerve vascular compression. Annals Otol Rhinol Laryngol. 2009;118(5):391-6.

Chadha NK, Weiner GM. Vascular loops causing otological symptoms:a systematic review and meta-analysis. Clinical Otolaryngol. 2008;33:5-11.

Makins AE, Nikolopoulos TP, Ludman C, O'Donoghue GM. Is there a correlation between vascular loops and unilateral auditory symptoms? Laryngoscope. 1998;108:1739-42.