Today’s post marks the first in the final series written by Dr. Bob Martin for HearingHealthMatters. As his final topic, Dr. Martin has chosen to write on connections linking migraines and hearing health. We are honored that Dr. Martin has contributed on such a wide variety of topics for us!
Audiologists play a variety of roles, from providing children with the hearing help they need to acquire speech and language skills to enabling adults with hearing loss to maintain communications with friends and family. But, perhaps our most essential role is that of diagnostician.
When a patient tells us, “I can’t hear in my left ear anymore,” we are handed a serious challenge, and the health and well being of the patient hang in the balance. Time is critical.
We must figure out not only the cause of the problem, but its gravity as well. Has a piece of dead tissue fallen across the ear canal? Or has something serious, such as sudden hearing loss, occurred?
Once we understand the cause, we must fix the problem, or make sure the patient sees the appropriate specialist as soon as possible. To do this we need to possess a comprehensive understanding of ear disease.
Our article for this week looks at vestibular-related migraine, and explains an intriguing new theory about the pathophysiology of this disorder. If that theory proves true, this condition will become another of the “diseases” we must be able to identify and differentiate from the myriad of other ear problems.
A GENETIC CAUSE FOR MIGRAINE
The theory of “vestibular related migraine” is so new that the condition does not yet have an official name. But, if this new explanation for the pathophysiology of this disease is verified, I expect it will be given a new name. I favor a descriptive term: Gb-M&E syndrome (Genetic-based Migraine and Ear syndrome). The letters G, M, and E are capitalized to stress the words “genetic,” “migraine,” and “ear.” The letter “b” is not capitalized to de-emphasize the word “based.” According to the new theory, a genetic defect is the “root” of the problem and the pathology is expressed (revealed) as migraine and ear disease.
If vestibular-related migraine does indeed prove to have a genetic origin that is expressed as a neural dysfunction, then treatments for this disorder will need to redirect their focus. In the past when we thought about ear problems we focused on “ear:” structures, tissues, and pathogens in the ear. As genetic defects are better understood, we must widen our focus and include the impact of DNA and genetic defects to our thought processes. Treatment strategies will change markedly—the new approach uses well-known systemic medications to calm down over active nerves.
Michael Teixido, MD, a noted neuro-otologist, has researched and written about this topic at length. Dr. Teixido says that scientists have discovered an inherited trait (a genetic defect) that they believe causes a dysfunction in the trigeminal nerve in most people who suffer from migraine headaches. This defect affects other parts of the human body as well. For example, some ear-and-nose disorders are probably a result of this trait.
THE VESTIBULAR-RELATED MIGRAINE THEORY
Here is an outline of this theory and how this condition affects the ear and nose.
- Genetic defects are passed along “family lines.”
- A specific genetic defect has been found that causes the trigeminal nerve to malfunction and release toxins that cause inflammation in a wide area of the head, ears, and nose.
- This genetic defect is common. Many patients have this problem.
- The conventional explanation of migraine has never been very convincing because the time line does not make sense. Conventional theory says a migraine headache results when blood vessels first contract, blood flow is reduced, the vessels then dilate, creating a highly sensitive condition that results the pain (the headache). The experience of pain does not happen when you would expect it.
- The new theory is more believable. The time line of the “cause” and the “typical symptoms” makes sense.
- It is important to note that not all people with migraine experience headaches. Migraine is a disease with a group of symptoms, not all of which are necessarily expressed or experienced in any given case. Following this logic, it is possible for a person with vestibular-related migraine to have an “ear” or “nose” problem and not have migraine headaches.
- To understand this disease and how to treat it, you need to understand both migraine headaches and how the flaws in the genetic code cause the Trigeminal nerve to activate the release of toxins.
- Most people who have migraines have abnormal habituation to certain stimuli (e.g., bright lights, some type of food, particular situations). Continuous exposure elicits a variety of symptoms.
- The new theory suggests that a genetic defect causes the C fibers in the Trigeminal nerve to release toxins into surrounding blood vessels. This inflammatory process can cause migraine headaches and a variety of ear-and-nose diseases.
- This toxic release may be the cause, or one cause of Meneire’s disease. This seems likely because the correlation of people with Meneire’s disease and migraine headache is very high.
- Many people who have vertigo also have migraine headaches and the same “cause” is suspected.
- Researchers are attempting to develop a “habituation/growth” auditory test for vestibular related migraine. This test would be helpful in diagnosing people with this defect.
- According to Dr. Teixido, the most effective treatment for people with this disorder is not conventional therapy aimed at the end organ. Rather it is to treat the ear-or-nose tissue by treating (calming down) the nerves that serve the ear and nose.
In the past it was difficult to explain the cause of some ear-and-nose diseases like Meniere’s disease and sinus headaches. A defective gene and an abnormally functioning trigeminal nerve may be the cause.
I will continue discussing this topic in future blogs.
feature image courtesy of PBS.org