Familial unilateral deafness and delayed endolymphatic hydrops.

Delayed endolymphatic hydrops (DEH) is a unique disorder characterized by fluctuating otologic symptoms in the setting of preexisting unilateral deafness. The symptoms include aural fullness, fluctuating hearing, and/or episodes of vertigo similar to those observed in Meniere disease and may occur ipsilateral or contralateral to the previously deafened ear. In most reported cases, the unilateral deafness has been a profound sensorineural hearing loss with a sudden onset that has been variously attributed to bacterial or viral labyrinthitis, acoustic or cranial trauma, otosclerosis, and congenital CMV infection.

Delayed endolymphatic hydrops as a clinical entity.

Delayed endolymphatic hydrops (DEH) is a clinical entity that can be differentiated from Ménière's disease and is typically observed in patients who have been suffering from longstanding unilateral profound inner-ear hearing loss. DEH probably is caused by delayed atrophy or fibrous obliteration of the endolymphatic resorptive system of the membranous labyrinth. The time that elapses between the occurrence of hearing loss and the onset of DEH can range from 1 to 74 years.