Letter to the editor European Archives of Oto-Rhino-Laryngology

A recent article by Gujardo-Vergara et al. Endolymphatic Hydrops in the Unaffected Ears of Patients with Unilateral Meniere's Disease in European Archives of Oto-Rhino-Laryngology 2022 https://doi.org/10.1007/s00405-022-07412-9 raises some important new questions about Meniere's disease.

There has been a long-standing belief that in Meniere's disease, the hydrops always begins in the cochlea. As the basis of the two main attack mechanism theories it is in part an assumption, but a multi-institutional post-mortem study supports it [1]. Briefly, theories for the underlying cause of Meniere disease have been inner ear ischaemia, a variation in the size or position of the endolymphatic duct or sac, a viral infection of the endolymphatic sac, an autoimmune or allergic cause, or (assuming a provable family history) a genetically determined abnormality of endolymph control, or some combination of these. There have been two main competing theories as to attack mechanism. These are Schuknecht's rupture and potassium intoxication theory [2] and the Gibson–Arenberg 'drainage' theory [3]. Both assume a process triggered by existing cochlear hydrops.

Assuming initial cochlear hydrops is the basis of Meniere's disease some of the results in this paper require explaining. In the Meniere's ears, 18% had no 'visible' hydrops. The important question must now be does hydrops always commence in the cochlea? Or, is it a technical issue? There are reasons to suspect that scanning using intravenous Gadolinium, compared with intratympanic under-detects cochlear hydrops [4]. If that is true, it is a serious issue that needs to be clarified.

In regards to opposite or non-affected ears, the study found mild or moderate cochlear hydrops in 13%, as well as vestibular hydrops in 24% of ears. While not the main point of this letter, it might be pondered as to why an ear with normal hearing and mild/moderate hydrops, even after years, can suddenly convert into Meniere's disease. The possibility that saccular otoconia may be an underlying cause [5] might be at least one explanation. Proof or disproof will require significant advances in living inner ear imaging.

留言 (0)

沒有登入
gif