The recent criteria for classification of Ménière's Disease (MD) from the Barany Society, published in 2015, also distinguish probable MD and definite MD. The former is defined as two or more episodes of vertigo or dizziness, each lasting 20 minutes to 24 hours with fluctuating aural symptoms (hearing, tinnitus or fullness). Definite MD is diagnosed in the setting of two or more spontaneous episodes of vertigo, each lasting 20 minutes to 12 hours with an audiometrically documented low to medium frequency sensorineural hearing loss in the affected ear on at least one occasion, before, during or after one of the episodes of vertigo, as well as fluctuating aural symptoms in the affected ear.

It is evident that the lines are blurry at times between MD and VM and that some patients may present with features of both diseases. In deed, MD patients can present with some migrainous features, notably photosensitivity and motion sickness but can also have headaches. These headaches do not always fulfill the criteria for migraines according to ICHD.

One frequent confounder is sinus headaches. It is estimated that over 75% of self-reported sinus headaches (sinus pain, sinus fullness-with normal CT scan of the sinuses), are actually migrainous in origin. In addition, the vast majority of patients with ICHD migraine headaches report nasal and sinus symptoms. The activation of the trigeminal pathways in migraineurs is postulated to be the cause for these "mimickers" of sinus disease. On the other hand, it is sometimes difficult, especially early in the disease process to document a low frequency sensorineural hearing loss if the patient does not present to the clinic close to the "spell". If a patient fulfills criteria for both probable MD and probable VM, does he have Ménière's disease or does he have Migraines? Is there an overlap syndrome? Are these two pathologies on a different spectrum of the same disease?

 

The confusion goes even further when we look at the modalities of treatment of both pathologies. Low salt diet can prevent hypovolemia by decreasing diuresis which will mean it will prevent dehydration. Dehydration is a common trigger for migraineurs. Allergies and low barometric pressure are also major triggers for both pathologies, with the caveat that these so-called allergies may actually be migraine-related sinonasal symptoms. Finally, migraine is currently considered to be a channelopathy with alteration of ion channel functions, which disturbs the electrolyte distribution within the cell and in the interior milieu. The medications used for prevention are all ion channel modifiers, whether it is sodium-channel blockers such as nortriptyline and propranolol, calcium-channel blockers such as verapamil or GABAergic receptors activators such as topiramate. When we look at the endolymphatic space physiology, all of these ion channels are present in abundance within the lining cells. A channelopathy expressed in the inner ear could very well be the pathophysiological primer of MD...Of course, this is still speculation at this point.