ISSN 1308-7649 | E-ISSN 2148-3817
Original Article
Is Cerebellar Ataxia, Neuropathy, and Vestibular Areflexia Syndrome (CANVAS) a Vestibular Ganglionopathy?
1 Department of Neurology, Dr. César Milstein Hospital, Buenos Aires, Argentina ; Department of Neurology, Memory and Balance Clinic, Capital Federal, Argentina  
2 Department of Neurology, Dr. César Milstein Hospital, Buenos Aires, Argentina.  
3 Department of Neurology, Northwestern University, Chicago, USA  
J Int Adv Otol 2019; 15: 304-308
DOI: 10.5152/iao.2019.7068
Key Words: Cerebellar ataxia, vestibulopathy, neuronopathy, ganglionopathy, video head impulse test, VEMP
Abstract

 

OBJECTIVES: CANVAS is an acronym for cerebellar ataxia, neuropathy and vestibular areflexia syndrome. Limited autopsy data has suggested that CANVAS is caused by a focal dorsal root ganglionopathy that damages Scarpa’s (vestibular) ganglion, but spares the Spiral (hearing) ganglion. If the vestibular areflexia of CANVAS is in fact due to ganglionopathy, then there should be global reduction of all vestibular responses.

 

MATERIALS and METHODS: With this hypothesis in mind, a retrospective review of 5 subjects who met the clinical criteria for CANVAS was performed. Recent advances in vestibular testing have made it possible to quantify responses from all 5 vestibular end organs in the inner ear. Results of the Video head impulse test (VHIT), video oculography, caloric test and vestibular evoked myogenic potential (VEMP) were examined to determine if all 5 end organs are nonfunctional in CANVAS.

 

RESULTS: Severe reduction of function of the six semicircular canals and ocular VEMPs were observed. Only the cervical VEMPs were present and reproducible, consistent with either partial sparing of the inferior vestibular ganglia, specific embryologic resistance of the saccule to the degeneration or a mechanism for cervical VEMPs that does not require an intact vestibular ganglion.

 

CONCLUSION: Our results suggest that Scarpa´s ganglia dysfunction could be the mechanism for loss of semicircular canal and utricular function in CANVAS patients, but the preservation of the cervical VEMP response is unexplained.

 

Cite this article as: Yacovino DA, Zanotti E, Hain TC. Is Cerebellar Ataxia, Neuropathy, and Vestibular Areflexia Syndrome (CANVAS) a Vestibular Ganglionopathy? J Int Adv Otol 2019; 15(2): 304-8.

Key Words
Authors
All
Author's Corner
Reviewer's Corner
Survey
AVES | Copyright © 2019 The European Academy of Otology and Neurotology | Latest Update: 15.08.2019