Experimental Autoimmune Inner Ear Disease: An Electrocochleographic and Histophysiologic Study

Systemic immunization with swine inner ear antigens in complete Freund's adjuvant induces functional disturbances in the cochlea. Morphometric data indicate that an endolymphatic hydrops develops within 2 weeks. It diminishes 6 weeks after immunization. A progressive decrease in the compound action potential amplitude is observed from 2 to 6 weeks after immunization. Enhancement of the amplitude of the summating potential is present without a clear overall correlation to the presence of endolymphatic hydrops. The amplitude of the cochlear microphonics shows no significant changes after immunization. Western blot analysis of the sera performed 2 and 6 weeks after immunization shows enhanced reactivity at 68,50,45, and 27 kd molecular weights, as compared to controls. The same spectrum of cross-reacting antibodies is believed to be instrumental in immune-mediated sensorineural hearing loss in patients. Apparently, cross-reacting antibodies and released mediators disturb cochlear homeostasis, resulting in the observed changes in the electrophysiological responses. However, these changes are not clearly related to structural changes at the light and electron microscopic levels.

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Intratympanic gadolinium magnetic resonance imaging supports the role of endolymphatic hydrops in the pathogenesis of immune-mediated inner-ear disease

The Journal of Laryngology & Otology ◽

10.1017/s0022215118000749 ◽

2018 ◽

Vol 132 (06) ◽

pp. 554-559 ◽

Cited By ~ 13

Author(s):

D Lobo ◽

M Tuñón ◽

I Villarreal ◽

B Brea ◽

J R García-Berrocal

Keyword(s):

Magnetic Resonance Imaging ◽

Magnetic Resonance ◽

Inner Ear ◽

Endolymphatic Hydrops ◽

Tertiary Care ◽

Resonance Imaging ◽

Virtual Absence ◽

Imaging Result ◽

Immune Mediated ◽

Inner Ear Disease

AbstractObjectiveTo evaluate the presence of endolymphatic hydrops in patients with immune-mediated inner-ear disease.MethodsThe presence of endolymphatic hydrops was prospectively evaluated in 17 patients clinically diagnosed with secondary (n = 5) or primary (n = 12) immune-mediated inner-ear disease, who attended the ENT department of a tertiary care centre for evaluation or treatment over the previous year. All patients underwent magnetic resonance imaging of the temporal bone.ResultsIntratympanic gadolinium three-dimensional magnetic resonance imaging diagnosed hydrops in 11 of 12 patients with primary immune-mediated inner-ear disease (92 per cent). Of these, seven patients (64 per cent) presented only cochlear (n = 5) or predominantly cochlear (n = 2) hydrops. A positive magnetic resonance imaging result was observed in only one of five patients with secondary immune-mediated inner-ear disease (20 per cent).ConclusionThis study confirms the presence of endolymphatic hydrops in immune-mediated inner-ear disease patients. The virtual absence of hydrops in patients with secondary immune-mediated inner-ear disease is remarkable, although firm conclusions cannot be drawn; this should be explored in a multicentre study with a larger sample of patients. A different immune reaction without development of endolymphatic hydrops should not be ruled out in secondary immune-mediated inner-ear disease patients.

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