Cochleo-Vestibular Disorders in Herpes Zoster Oticus: A Literature Review and a Case of Bilateral Vestibular Hypofunction in Unilateral HZO

Abstract

The varicella-zoster virus (VZV), a member of the Herpesviridae family, causes both the initial varicella infection and subsequent zoster episodes. Disorders of the eighth cranial nerve are common in people with herpes zoster oticus (HZO). We performed a review of the literature on different databases including PubMed and SCOPUS, focusing on cochlear and vestibular symptoms; 38 studies were considered in our review. A high percentage of cases of HZO provokes cochlear and vestibular symptoms, hearing loss and vertigo, whose onset is normally preceded by vesicles on the external ear. It is still under debate if the sites of damage are the inferior/superior vestibular nerves and cochlear nerves or a direct localization of the infection in the inner ear. The involvement of other contiguous cranial nerves has also been reported in a few cases. We report the case of a patient with single-side HZO presenting clinical manifestations of cochleo-vestibular damage without neurological and meningeal signs; after 15 days, the patient developed a new episode of vertigo with clinical findings of acute contralateral vestibular loss. To our knowledge, only three other such cases have been published. An autoimmune etiology may be considered to explain these findings.

Keywords: Ramsay Hunt syndrome; bilateral cochleo-vestibular damage; facial palsy; hearing loss; herpes zoster oticus; magnetic resonance imaging; vestibular disorders.

Figure 1

Search strategy flowchart. * Publications citing HZO but not focused strictly on the argument and not presenting new data were excluded.

Figure 2

Spontaneous nystagmus (A), cervical VEMPs (B), audiometric exam (C), and video head impulse test (D) at first evaluation showing left cochleo-vestibular damage.

Figure 3

Results of audiometric exam (A) and video head impulse test (B) at the onset of contralateral vestibular damage. Right side in red, left side in blue. Audiometric exam did not show changes, while bilateral vestibular damage was found.

Figure 4

(A–C) MRI scan with contrast of the patient after the second hospitalization; (D–F) MRI scan without contrast performed during the first hospitalization. (A,B,D,F) T2-weighted images; (C,F) FLAIR images. (A–C) Hyperintense lesion (red arrows) in the posterior lower pons on the left side extended to the medulla, in the presumed side of cochlear and vestibular nuclei.

Figure 5

(A) T2-weighted image; (B) T1-weighted image post-contrast administration; (C,D) diffusion-weighted imaging b-1000 and apparent coefficient diffusion map, respectively. The lesion lacked contrast enhancement (B) and there was no diffusion restriction of water within the alteration (C,D).

Figure 6

Audiometric exam (A) and video head impulse test (B) performed at 2 months after discharge.