Clinical characteristics of delayed endolymphatic hydrops in Japan: A nationwide survey by the Peripheral Vestibular Disorder Research Committee of Japan

Abstract

Conclusion: Similarly to almost all delayed endolymphatic hydrops (DEH) cases with both precedent sudden deafness and mumps deafness, two-thirds of DEH cases with precedent deafness of unknown cause with onset in early childhood developed DEH symptoms within 40 years after the precedent deafness. In spite of the diagnosis of precedent deafness, viral labyrinthitis may build up the late endolymphatic hydrops in most DEH cases up to four decades. Objective: To clarify the characteristics of DEH in Japan. Methods: Clinical information on 198 DEH cases was collected by nationwide, multicenter surveys conducted by the Peripheral Vestibular Disorders Research Committee of Japan. Results: The incidence of the ipsilateral type of DEH was 47.5%, which was almost equal to that of the contralateral type. In both types of DEH, the most common diagnosis of precedent deafness was deafness of unknown cause with onset in early childhood: 43.9% in both types of DEH. Sudden deafness and mumps deafness were the subsequent diagnoses of precedent deafness. The distribution of time delay of the onset between precedent deafness of unknown cause with onset in early childhood and DEH was different from that between precedent sudden and mumps deafness and DEH.

Keywords::

• Ipsilateral
• contralateral
• cause of profound hearing loss
• onset age
• Time delay of onset between precedent deafness and DEH

Acknowledgments

This work was supported by a grant from the Ministry of Health, Labor and Welfare of Japan. We express our sincere appreciation to all members of the Department of Otolaryngology, University of Toyama, for their assistance and cooperation.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.