Lesion Patterns and Possible Implications for Recovery in Acute Unilateral Vestibulopathy.

Abstract

To assess patterns of end-organ involvement in acute unilateral vestibulopathy (AUV) and to define the recovery. Retrospective chart review. Tertiary academic referral hospital. Fifty-nine patients fulfilling clinical criteria for AUV and evaluated using the caloric vestibular test, video head impulse test, and both cervical and ocular vestibular evoked myogenic potentials, up to 10 days from symptoms onset were included. Vestibular tests and requirements for vestibular rehabilitation were analyzed. The most affected end-organ was the horizontal canal (97%), followed by the anterior canal (83%), utricle (73%), posterior canal (46%), and saccule (44%). Nineteen (32%) patients exhibited complete receptors lesion, while 13 (22%) exhibited damage to receptors connected with the superior division of the vestibular nerve (VN). The proportion of patients who underwent vestibular rehabilitation was higher in the latter two groups (58% for both). Partial involvement of the receptors innervated by both the division of the VN, rather than by its superior division, was detected in 22 and 24% of patients, respectively. Total or partial damage to receptors innervated by the inferior VN was not found. Deeper understanding of AUV may be achieved through identification of its patterns. Slightly more than one-half of AUV cases seemed to be associated with a nerve lesion, with a worse clinical outcome. The remaining patients exhibited selective involvement of vestibular receptors, more probably consistent with an intralabyrinthine lesion pattern and experienced better spontaneous recovery.