Migraine is a common cause of vertigo, yet the symptoms and temporal pattern differ enough from classic migraine that the International Headache Society has established criteria for “Vestibular Migraine” listed at the end of this blog. Similar to classic migraine, there is no specific test that confirms the diagnosis. Rather, diagnosis is made on the basis of clinical history, lack of evidence of any disease other than migraine that could cause similar symptoms, and response to migraine treatments.
While the majority of my posts reference peer-reviewed literature, this week I am just going to ramble. Most of my observations and thoughts are supported by the literature, but some are just based on my own experience.
Since the patient’s history is key to the diagnosis, I will offer a few non-scientific observations I have made while seeing many patients over the years with suspected vestibular migraine. The first is female predominance, the second is age. When I see a 30-to-50-year-old female with symptoms that do not point to a clear vestibular disorder, vestibular migraine is on my radar. Frequently, these patients have a history of classic migraine that disappeared at the time of a major hormonal event such as puberty, pregnancy, childbirth, hysterectomy, or menopause.
I have also observed that many of these women complain of adult onset motion intolerance and intolerance to external visual stimuli (such as light flickering through the trees when in a car). A major common feature is photophobia (increased sensitivity to light when vestibular migraine symptoms are present).
Another of my observations is that these patients do not like vestibular testing very much, particularly rotational chair and caloric testing. They are far more likely to become nauseous than normal or vestibular dysfunction patients.
This is just me thinking out loud, so be wary of accepting it as fact. The intolerance to motion and external visual stimuli suggests to me that even between episodes of vertigo vestibular migraine patients do not resolve sensory conflict in a normal manner. By that, I mean that when they are presented with something that most of us handle easily, they can’t make sense of it.
For example, caloric testing creates a conflict between what the right and left labyrinths are telling the brain. Most patients enjoy the ride and it’s over in a minute. Most people are slightly annoyed, but not overwhelmed, in a situation such as sitting at a rail crossing watching a train pass. In this situation, the eyes are telling the brain that you are moving, but a healthy brain and vestibular system can quickly determine that it’s the train that is moving, not you.
Vestibular Migrainers are confused and have strong reactions to both of these situations. The brain does not resolve the conflict between what the eye sees and what the ear senses.
This brings me to my next random thought. If the Vestibular Migraine brain does not resolve sensory conflict effectively, are these people compromised regarding compensating for any additional vestibular injury? Logic tells me “probably,” but I don’t know.
The International Headache Society lists these criteria for diagnosing vestibular migraine:
(A) At least 5 episodes with vestibular symptoms or moderate or severe intensity, lasting 5 min to 72 hr
(B) Current or previous history of migraine with or without aura according to the International Classification of Headache Disorders (ICHD)
(C) One or more migraine features with at least 50% of the vestibular episodes:
a. Headache with at least two of the following characteristics: one-sided location, pulsating quality, moderate or severe pain intensity, aggravation by routine physical activity
b. Photophobia and phonophobia
c. Visual aura
(D) Not better accounted for by another vestibular or ICHD diagnosis”
(Lembert, T., 2013)
Photo courtesy of http://beltzmanor.blogspot.com/