Varicella-zoster virus load and cochleovestibular symptoms in Ramsay Hunt syndrome

The mechanism by which varicella-zoster virus (VZV) reactivation causes cochleovestibular symptoms (CVSs) in patients with Ramsay Hunt syndrome (RHS) remains to be elucidated. The present study analyzed the relationship between VZV load and the onset of CVSs in RHS.

The subjects consisted of 56 patients with RHS; 29 exhibited CVSs and facial paralysis (FP; group 1), and 27 exhibited FP without CVSs (group 2). The VZV DNA copy number in the saliva was measured with a quantitative polymerase chain reaction. Anti-VZV antibodies were assayed by an enzyme-linked immunosorbent assay with paired sera.

There was no significant difference in maximum viral copy number between the two groups. In group 1, CVSs occurred at various times between the early phase and the regression phase of VZV reactivation. In some patients, CVSs occurred in the early phase of VZV reactivation, before the onset of zoster lesions and FP.

There are various different patterns in the development of eighth cranial nerve dysfunction, which is caused by progression of neuritis or labyrinthitis following VZV reactivation. Our data suggest that CVSs in RHS may also be caused by reactivation of VZV in the spiral and/or vestibular ganglia.