A1.6.6 Vestibular migraine

Previously used terms:
Migraine-associated vertigo/dizziness; migraine-related vestibulopathy; migrainous vertigo.

Diagnostic criteria:
A. At least five episodes fulfilling criteria C and D
B. A current or past history of 1.1 Migraine without aura or 1.2 Migraine with aura1
C. Vestibular symptoms2 of moderate or severe intensity3, lasting between 5 min and 72 hr4
D. At least 50% of episodes are associated with at least one of the following three migrainous features5:

    1. headache with at least two of the following four characteristics:

      a) unilateral location
      b) pulsating quality
      c) moderate or severe intensity
      d) aggravation by routine physical activity

    2. photophobia and phonophobia6
    3. visual aura7

E. Not better accounted for by another ICHD-3 diagnosis or by another vestibular disorder8.

Notes:

1. Code also for the underlying migraine diagnosis.

2. Vestibular symptoms, as defined by the Bárány Society’s Classification of Vestibular Symptoms and qualifying for a diagnosis of A1.6.5 Vestibular migraine, include:

    a) spontaneous vertigo:

      i. internal vertigo (a false sensation of self-motion);
      ii. external vertigo ( a false sensation that the visual surround is spinning or flowing);

    b) positional vertigo, occurring after a change of head position;
    c) visually-induced vertigo, triggered by a complex or large moving visual stimulus;
    d) head motion-induced vertigo, occurring during head motion;
    e) head motion-induced dizziness with nausea (dizziness is characterized by a sensation of disturbed spatial orientation; other forms of dizziness are currently not included in the classification of vestibular migraine).

3. Vestibular symptoms are rated moderate when they interfere with but do not prevent daily activities and severe when daily activities cannot be continued.

4. Duration of episodes is highly variable. About 30% of patients have episodes lasting minutes, 30% have attacks for hours and another 30% have attacks over several days. The remaining 10% have attacks lasting seconds only, which tend to occur repeatedly during head motion, visual stimulation or after changes of head position. In these patients, episode duration is defined as the total period during which short attacks recur. At the other end of the spectrum, there are patients who may take four weeks to recover fully from an episode. However, the core episode rarely exceeds 72 hours.

5. One symptom is sufficient during a single episode. Different symptoms may occur during different episodes. Associated symptoms may occur before, during or after the vestibular symptoms.

6. Phonophobia is defined as sound-induced discomfort. It is a transient and bilateral phenomenon that must be differentiated from recruitment, which is often unilateral and persistent. Recruitment leads to an enhanced perception and often distortion of loud sounds in an ear with decreased hearing.

7. Visual auras are characterized by bright scintillating lights or zigzag lines, often with a scotoma that interferes with reading. Visual auras typically expand over 5-20 minutes and last for less than 60 minutes. They are often, but not always restricted to one hemifield. Other types of migraine aura, eg, somatosensory or dysphasic aura, are not included as diagnostic criteria because their phenomenology is less specific and most patients also have visual auras.

8. History and physical examinations do not suggest another vestibular disorder or such a disorder has been considered but ruled out by appropriate investigations or such a disorder is present as a comorbid or independent condition, but episodes can be clearly differentiated. Migraine attacks may be induced by vestibular stimulation. Therefore, the differential diagnosis should include other vestibular disorders complicated by superimposed migraine attacks.

Comments:
Other symptoms
Transient auditory symptoms, nausea, vomiting, prostration and susceptibility to motion sickness may be associated with A1.6.5 Vestibular migraine. However, since they also occur with various other vestibular disorders, they are not included as diagnostic criteria.

Relation to migraine aura and migraine with brainstem aura
Both migraine aura and migraine with brainstem aura (formerly: basilar-type migraine) are terms defined by ICHD-3 (beta). Only a minority of patients with A1.6.5 Vestibular migraine experience their vertigo in the time frame of 5-60 minutes as defined for an aura symptom. Even fewer have their vertigo immediately before headache starts, as required for 1.2.1.1 Typical aura with headache. Therefore, episodes of A1.6.5 Vestibular migraine cannot be regarded as migraine auras.

Although vertigo is reported by more than 60% of patients with 1.2.2 Migraine with brainstem aura, ICHD-3 (beta) requires at least two brainstem symptoms in addition to visual, sensory or dysphasic aura symptoms for this diagnosis. Fewer than 10% of patients with A1.6.5 Vestibular migraine fulfil these criteria. Therefore, A1.6.5 Vestibular migraine and 1.2.2 Migraine with brainstem aura are not synonymous, although individual patients may meet the diagnostic criteria for both disorders.

Relation to benign paroxysmal vertigo
While A1.6.5 Vestibular migraine may start at any age, ICHD-3 (beta) specifically recognizes a childhood disorder, 1.6.2 Benign paroxysmal vertigo. The diagnosis requires five episodes of vertigo, occurring without warning and resolving spontaneously after minutes to hours. Between episodes, neurological examination, audiometry, vestibular functions and EEG must be normal. A unilateral throbbing headache may occur during attacks but is not a mandatory criterion. 1.6.2 Benign paroxysmal vertigo is regarded as one of the precursor syndromes of migraine. Therefore, previous migraine headaches are not required for diagnosis. Since the classification of A1.6.5 Vestibular migraine does not involve any age limit, the diagnosis can be applied in children when the respective criteria are met. Only children with different types of vertigo attacks, eg, short-duration episodes of less than five minutes and longer-lasting ones of more than five minutes, should receive both these diagnoses.

Overlap with Menière’s disease
1. Migraine is more common in patients with Menière’s disease than in healthy controls. Many patients with features of both Menière’s disease and A1.6.5 Vestibular migraine have been reported. In fact, migraine and Menière’s disease can be inherited as a symptom cluster. Fluctuating hearing loss, tinnitus and aural pressure may occur in A1.6.5 Vestibular migraine, but hearing loss does not progress to profound levels. Similarly, migraine headaches, photophobia and even migraine auras are common during Menière attacks. The pathophysiological relationship between A1.6.5 Vestibular migraine and Menière’s disease remains uncertain. In the first year after onset of symptoms, differentiation between them may be challenging, since Menière’s disease can be monosymptomatic with only vestibular symptoms in the early stages of the disease.

When the criteria for Menière’s disease are met, particularly hearing loss as documented by audiometry, Menière’s disease should be diagnosed, even when migraine symptoms occur during the vestibular attacks. Only patients who have two different types of attacks, one fulfilling the criteria for A1.6.5 Vestibular migraine and the other for Menière’s disease, should be diagnosed with both disorders. A future revision of ICHD may include a vestibular migraine/Menière’s disease overlap syndrome.