Sympathetic Inner Ear Disease

Timothy C. Hain, MD • Page last modified: July 31, 2022

See also: aiedanti-gq1bASbehcets_diseasecoganpatientsympatheticpandas

In the eye, there is a syndrome called "sympathetic ophthalmia", where following a penetrating injury to one eye, the other eye may go blind. The corresponding situation in the ear is to go deaf in one ear, following trauma or surgery performed on the opposite ear. This is thought to be due to release of antigen from the injured eye, causing an immune response, and blindness on the opposite side.

Over about 25 years of practice the author of this page has seen several patients who develop ear disease in a delayed fashion in the opposite ear where there was a different ear disorder. For example, this can occur in patients with an acoustic neuroma, including one patient following gamma knife "surgery". For the most part, this happens in patients who have undergone surgery. However, we have also encountered this in a patient who was unoperated. Generally speaking, this is attributed to autoimmune inner ear disease, the idea being that antigen is released during the surgery, and stimulates the immune system to attack the other ear.

In acoustic neuroma patients, hearing loss in the opposite ear is reasonably well documented. According to Early et al (2020), "Patients with normal baseline hearing bilaterally (N = 241) demonstrated no significant difference in hearing loss progression in VS-contralateral vs. control ears. Patients with abnormal baseline VS-ipsilateral hearing (N = 190), however, demonstrated significantly higher likelihood of reaching moderate SNHL in VS-contralateral ears. " Note that they are not saying that 190/661 patients lost hearing on the opposite side, but rather that there was a "significantly higher likelihood" of moderate hearing loss. This is not at all the same thing. In patients with acoustic tumors, it may also be that the hearing progression in the opposite ear is related to "secreted tumor factors". (Early et al, 2020) This idea seems a little suspicious to us. Why would acoustic tumors, that obviously cause hearing loss by mechanical factors, secrete "tumor factors", that somehow zoom over to the other ear and cause hearing loss. Hmmm.

In operated patients, another potential explanation of this observation of contrateral hearing loss is that there might be a chronic CSF leak, as these are known to impair hearing on both sides.

There have been cases reported of development of AIED in the opposite ear after surgery for Meniere's disease (Ochoa and Weider, 2003), 11 years after a temporal bone fracture (ten Cate and Bachor, 2005), and in 2 of 148 patients after stapes surgery (Richards et al, 2002). The author has also seen this occur as a late complication in persons who have had operations for perilymphatic fistula.

Lacking much organized data other than the stapes study, and considering our personal observations, we suspect that this occurs in about 1% of patients in which inner ear antigen is released into the body. A systematic error in this reasoning is that in most situations, a CSF leak could also be present. It is also possible that these cases are arising by chance combination of Meniere's disease and other ear disease.

Of course, this is a dangerous situation as patients who may be deaf, or going deaf in one ear, are developing deafness on the opposite side.

While this is generally only considered in hearing cases, it seems plausible that a similar picture might also occur with the vestibular part of the ear. We have encountered cases where there is bilateral vestibular loss after inner ear surgery, but as yet, we have not found any unequivocal cases.

Case: Patient with acoustic neuroma (unoperated) and bilateral hearing impairment.

MRI of showing acoustic neuroma on L Bilateral hearing loss in patient with AN
An acoustic neuroma is seen within the left 8th nerve on this contrast enhanced coronal MRI. The left ear has a high-frequency SNHL, consistent with her known acoustic neuroma. The right ear has a "peaked" hearing loss, consistent with Meniere's disease.

This middle aged individual has an enhancing mass on the left side, consistent with an acoustic neuroma. There were clear signs of unilateral vestibular loss on the acoustic side (left). The patient was also noticed to have a "peaked" type hearing loss on the other side. This hearing loss fluctuated and actually improved after steroids, while on the left side, hearing declined with time. As there was no surgery done, a CSF leak would be highly unlikely.

Case 2:

 

Audiogram 1 year post gamma knife
Audiogram about 1 year after gamma knife.
Audiogram of patient 2
Audiogram about 5 years after gamma knife.
Second audiogram
Audiogram about 1 year later showing deterioration on left.

A 70 year old woman had a right sided acoustic neuroma treated with gamma knife. There was clear myokymia of the mentalis, presumably due to radiation. About 5 years later, she developed fluctuating hearing on the left side. The hearing was on the left side largely low-tone. Over time, her hearing fluctuated but gradually worsened on the left. There were clear signs of unilateral vestibular loss on the right as would be expected from her tumor and gamma knife combined. Eventually her hearing stablilzed, while taking verapamil 120 SR, and as needed vestibular suppressants. This may have been burn out, rather than drug effect.


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