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 Dissociation between a video head impulse test and reduced caloric response had high specificity for differentiating vestibular migraine from Ménière’s disease.

“Vestibular migraine (VM) and Ménière’s disease (MD) are characterized by episodes of vertigo of similar duration,” researchers wrote in Frontiers in Neurology. “It is well known that differentiation between both diseases is not always possible based only on the patient history, physical examination, and audiological testing. In addition, the quantification of the vestibular function can also be helpful since, among patients with MD, there is often a dissociation between a normal/pseudo-normal video head impulse test and reduced caloric testing.”

Vergil Mavrodiev, PhD, and colleagues aimed, in a confirmatory study, to establish the sensitivity, specificity, and positive and negative predictive values (PPV and NPV) of this dissociation between a normal/pseudo-normal video head impulse test and reduced caloric testing to distinguish between MD and VM as well as between MD and other vestibular diseases. The retrospective analysis included 2,101 patients. In the examination group (n=1,100), 627 patients (57%) had MD based on the diagnostic criteria of the Bárány Society and 473 (43%) had VM. The comparison group included 1,001 patients with other peripheral, central, or functional vestibular disorders.

Dissociation Distinguishes MD From VM

The researchers found that, for the disassociation’s ability to differentiate MD from VM, specificity was 83.5%, sensitivity was 58.9%, the PPV was 82.6%, and the NPV was 60.5%. For differentiating MD from all other vestibular disorders, including VM, specificity was 83.5%, sensitivity was 58.9%, the PPV was 60.3%, and the NPV was 82.7%.

Further, Dr. Mavrodiev and colleagues noted that the dissociation between a normal video head impulse test and a reduced caloric response was due to the high specificity and PPV suited for the differentiation between MD and VM.

The researchers noted that this aspect of the study confirms prior results seen in a large cohort of patients. This indicates that, when differentiating between MD and all observed vestibular disorders, the diagnosis of MD is unlikely if there is no dissociation.

“Considering the differentiation between MD and VM, the discrepancy was highly specific for MD (83.5%),” Dr. Mavrodiev and colleagues wrote. “Together with a low percentage of false-positive results and a high positive predictive value (82.6%), it can be used as an assisting rule-out test for MD—especially in patients lacking the typical MD symptoms in the early stages of the disease.”