Came across this on the vestibular website: http://vestibular.org/autoimmune-inner-ear-disease-aied What exactly is it? Has anyone been diagnosed with it? How is this different from Stephen's Spring's theory?
AFAIK SS's theory of Meniere's is that it's caused by the innate immune system - this is a non-specific inflammatory response, causing a build-up of fluid (hydrops). AIED is an adaptive immune response - that is, the body produces antibodies against the hair cells in the ear and destroys it. For some reason, the immune system suddenly decides that normal proteins in the ear are pathogens, and mounts a specific immune response against them. It quickly becomes bilateral, because the memory B cells (the cells that produce antibodies) are circulating in the blood and of course they soon come across the second ear, and decide it's "infected" with the same "pathogen" as the first, so get to work against that one too (it's the same principle as vaccination - the body remembers the antigen introduced by the vaccine and is primed and ready with antibodies the next time it comes across it). The same thing can happen with your eyes - if you damage one (in an accident or sometimes by surgery) and proteins usually contained only in the eye get into the blood, the immune system sees them as foreign and mounts an attack against them, which quickly damages the second eye, even though there was no physical cause of damage.
Nuttyneddy There are a couple of points that seem incongruous to me. Please can you define your use of the word ‘quickly’? Is that days, months, hours, years? And why do so many people remain bilateral?
Oops. I just noticed that my post should have read 'And why do so many people remain unilateral?' A grave error on my part due, no doubt, to rampant brain fog... Actually I have no excuses. But I still don’t understand how a systemic problem manifests itself in only one of two ears. I have always understood the chance of progression from unilateral to bilateral was 50%
The innate (nonspecific response) and adaptive (antigen-specific) immune system are interconnected as they talk to each other and are not readily separated. Meniere's and AIED are probably two sides of the same coin. The rate of unilateral becoming bilateral is probably multifactoral, including age of onset, anatomical differences between the two ears (most of us have one hand, eye, foot, that is slightly smaller than the other), viral load, differences in overall immune strength or weakness, etc. There is a theory that most people are in fact always bilateral, but each endolymphatic sac fails at a different rate.