Cytomegalovirus antibodies in endolymphatic sac biopsies of patients with endolymphatic hydrops and Ménière's disease.

Abstract

Numerous viruses have been implicated as ototropic and as a contributing or initiating factor in inner-ear disorders. These ototropic viruses (mumps, CMV, herpes simplex virus, varicella-zoster, and the coxsackie virus) can cause damage or death to various hair cells, resulting in hearing loss and balance disorders. CMV infections are classified as two major types: the first is clinically seen at birth and is systemic in nature, and the second is not clinically apparent at birth and is termed asymptomatic or subclinical. Importantly, both types of CMV infections have reported otologic sequelae and involvement with the property of neurotropism.'.2 Thirty to fifly percent of patients with symptomatic CMV have reported hearing whereas a substantially lower number (7-13%) of patients who are asymptomatic have reported hearing I o s s , ~ , ~ * ' presumably related to the CMV infection. Recent speculations suggest that CMV infections may not be solely associated with congenital infections, but also with the reactivation of latent virus or with primary infections later in life, or as a primary or secondary trigger mechanism. However, definitive evidence of a viral etiology of Menitre's disease is lacking. Menitre's disease may be secondary to dysfunction of the ELS. The main function of the ELS is to act as a resorptive site for endolymph and is the main defensive mechanism for the inner ear. It is an important site for endolymph absorption,* regulation of the inner ear and inner-ear fluid dynamic^.'^*'^ Recent evidence indicates that dysfunction of the ELS and its inability to resorb endolymph resulting in ELH, may be a contributing factor, but not the only factor in the development of Menikre's disease. Studies involving immunohistochemical