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A reader asks:

Can you address the benefits of gentamicin treatments for Meniere’s Disease?

We presume that you mean intratympanic instillation and perfusion of gentamicin. Click here to read about intratympanic instillation and perfusion in general at the MDIC (Meniere’s Disease Information Center). Click here to read about intratympanic gentamicin treatment at the MDIC. Together, these links to the MDIC are fairly comprehensive.

We presume that by “benefits” you mean benefits compared to surgical labyrinthectomy and vestibular neurectomy (vestibular nerve section (VNS)).

The purpose of intratympanic instillation and perfusion of gentamicin is to treat the symptom of vertigo that results from Meniere’s Disease. “Intratympanic instillation” means instilled “through the eardrum.” In other words, the gentamicin is injected through the eardrum into the middle ear (not the inner ear).

“Gent” is technically surgery because a hole is made in the tympanic membrane (the eardrum). This can be done by merely pushing a hypodermic-type needle through the membrane, by nicking the membrane with a small knife or scalpel, or by burning a hole in the membrance using a laser. But this is very low risk surgery. (”Low risk” does not mean “no risk,” though.) Usually the only anesthesia is a local, Novocain-like, anesthetic sprayed or swabbed onto the ear drum. General anesthesia is not usually (”not usually” does not mean “never”) used for this purpose. The procedure is almost always out-patient, and is often performed in a doctor’s office. Compared to “real” surgery, the cost is very low.

Set into a niche in the lower part of the bony wall that separates the middle ear from the inner ear is a membrane called the “round window.” Once the gentamicin is injected through the ear drum into the middle ear, the objective is to get it to settle in the niche over the round window and let gravity help it to perfuse through the membrane into the inner ear. This is accomplished by having the patient lie on the “good ear” with the “bad ear” skywards, allowing the gentamicin to settle into the round window niche. (Note that the gentamicin is not injected into the inner ear.)

Gentamicin is an antibiotic, but for this purpose its antibiotic properties are unimportant. Gentamicin also happens to be ototoxic — it damages the hearing and vestibular functions of the inner ear. It is an “ear poison.”

At lower strengths, there are two possible objectives, as described at the links to the MDIC above. One possible objective is to damage the tiny hairs (that are *not* “cilia,” by the way) that are at the endings of the vestibular branch of the 8th cranial (vestibulocochlear) nerve. These tiny ears convey balance signals through the nerve to the brain. The theory is that these tiny hairs, already damaged by Meniere’s Disease, are sending faulty balance signals to the brain, and that if they are further damaged enough, there will be fewer or *no* signals at all sent to the brain, not even faulty signals that result in vertigo.

The other possible objective is to damage the so-called dark cells that produce endolymph (one of two inner ear fluids, the other being perilymph), thereby reducing the amount of endolymph in the inner ear. The current favored theory about Meniere’s Disease is that it results from excess endolymph in the inner ear, either from over-production (too much is produced) or under-resorption (too little is resorbed in the endolymphatic sac).

The doctor may seek either or both of these possible objectives. There are various protocols for accomplishing these objectives. Click here to search medical journals at PubMed.

At lower strengths, the hope is that either the tiny hairs or the dark cells will be damaged but that existing hearing will be preserved in whole or in part. However, there is always some risk of further hearing damage or even deafness. (Refer to the journal articles for the results of the various trials.)

Therefore, the benefits of gentamicin treatment at lower strengths are: low risk, low cost, convenience, possible preservation of hearing, and it might work. Might. Nothing is for sure with Meniere’s Disease. (Refer the the journal articles for the results of the various trials.)

At higher doses, as described at the links to the MDIC above, gentamicin is intended to ablate (destroy) the labyrinth (consisting of both the vestibule (balance organ) and the cochlea (hearing organ)). This is called “chemical labyrinthectomy” (where the “chemical” is gentamicin (or streptomycin, another ototoxic drug that is incidentally an antibiotic)). This is usually done only when there is little or no remaining hearing and other treatments have failed. The idea is that the total destruction of the labyrinth will “take out” everything that is sending balance signals of any kind to the brain, thereby eliminating faulty balance signals that result in vertigo. The known and accepted consequence is that not only will balance be destroyed, but whatever hearing remains will also be destroyed.

Therefore, the benefits of gentamicin treatment at higher strengths are: low risk, low cost, convenience, and it might work. Might. Nothing is for sure with Meniere’s Disease. (Refer the the journal articles for the results of the various trials.) An accepted consequence is deafness.

Compare the chemical labyrinthectomy to the surgical labyrinthectomy. A surgical labyrinthectomy accomplishes the same goal as high dosage intratympanic gentamicin by physically removing the labyrinth. Under general anesthesia, the surgeon literally cuts out the labyrinth from the inner ear, including both the vestibule and the cochlea. However, general anesthesia is always risky, and labyrinth isn’t all that accessible. Sometimes the 7th cranial (facial) nerve is damaged in the process, and there is the risk of infection, among other risks. Read about surgical labyrinthectomy at the MDIC by clicking here.

Compared to chemical labyrinthectomy, surgical labyrinthectomy carries surgical risk, is high cost, inconvenient, involves recovery from surgery, and it might work. There are no guarantees with any Meniere’s Disease treatment.

Then there is vestibular neurectomy surgery. Vestibular neurectomy (vestibular nerve section (VNS)) is surgery to section (sever) the vestibular branch of the 8th cranial (vestibulocochlear) nerve near where it connects to the brain. Once again, the objective is to block all balance signals, including faulty balance signals causing vertigo, from reaching the brain. This is very invasive intra-cranial surgery and is very risky. Read more about vestibular neurectomy and its risks at the MDIC by clicking here. This is high risk surgery, very high cost, very inconvenient, has a substantial recovery period, and it often works to reduce or eliminate vertigo. “Often” is not “always.”

The only thing certain about treating Meniere’s Disease is that the outcome is uncertain.

Read more about the various treatments of Meniere’s Disease at the MDIC by clicking here.

There is an article in tomorrrow’s (October 30, 2005) New York Times on what is called variously “boutique” or “concierge” medicine. (Some promoters prefer the term “personalized” medicine.) A lot has been written about this emerging business model of health care. Click here to search Google for more information.

It works like this. Most doctors have a client base of perhaps 2,500 clients. The doctor gets paid, more or less, by how many patients are seen. The more patients that can be crammed into an hour, the more the doctor gets paid. Doctors have huge overhead costs, beginning with their medical school loans and lost wages for the time they spent in medical school, office expenses, medical equipment, medical support staff, administrative staff, medical journals, and the time away from patients that it takes to read the medical journals, and all this is just for starters. Even with computers, the amount of time spent by doctors’ offices in insurance billing and disputes is staggering. And then there is the squeeze put on the doctor’s fees by Medicare and by some insurance companies. Medicare reimbursements are, well, paltry, which is why some doctors won’t take Medicare patients. Some insurance plans demand agreements that, in effect, place caps on doctors’ fees for plan patients, if the doctors want to participate with those plans.

The most frequent and fervent complaint that I have heard from Meniere’s Disease patients over years is that their doctors (1) don’t listen to them, and (2) don’t talk to them. I attribute this to a system that penalizes doctors for each minute that they spend with patients. (That’s an observation, not a criticism.) Moreover, I believe that the pressures of time on doctors can lead to misdiagnoses and less than optimal treatment plans. (That’s a criticism, not an observation.)

In the business models known as “boutique” or “concierge” medicine, the time pressure is relieved. Doctors limit the number of patients in their practices, perhaps to 500 or 600. Think of all the time that frees up! But the lost money from fewer patient visits has to come from someplace. That place is what can be called, more or less, a “membership fee.” That fee can be any amount, but most of the reported fees that I have seen run between $1,000 and $2,000 a year. Here’s the math: that averages out to $83-$166 a month. In return, the doctor can see you almost right away, because there are 2000 fewer patients to queue up ahead of you. The doctor can spend more time with you — perhaps even have a cup of coffee with you and chat. That 10 minute visit can become a 60-minute visit.

Under that business model, a doctor with 500 patients paying, say, $1,500 per year each will receive $750,000 per year up front. Of course, you still have your insurance, and your doctor still receives insurance fees on top of that $750,000 — and you still pay your deductibles. (For even higher yearly membership fees, even that can change.) But the pressure on the doctor is relieved. The doctor may even have time enough to research Meniere’s Disease and figure out what it is. (That’s not a mean statement; that is a statement of the reality in many cases.)

Many of us cannot afford to pay that membership fee. Many of us, like many people in America, have no health insurance at all. One thing that has always struck me about Menierians is that we mostly seem to be on the lower rungs of the economic ladder. Or perhaps I only see a skewed sample. In any event, cost is always a factor.

But consider this. Many patients, without thinking much about it, relegate medical expenses to the bottoms of their budgets. They seem constrained by what their insurance will pay. They are reluctant to pay for travel out of town to see a more knowledgeable doctor. They refuse to sacrifice vacations for medical care. They pay for new SUV’s but won’t spend a dime to see a doctor “out of plan.”

Perhaps one strategy would be for a patient to join a boutique plan for a year or two until that patient finds a diagnosis and treatment plan that works, and then leave the boutique for future followup.

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