Criteria proposed for a diagnosis of definite migrainous vertigo are :
- Recurrent episodic vestibular symptoms of at least moderate severity and
- Current or previous history of migraine according to the criteria of the International Headache Society (IHS) and
- One of the following migrainous symptoms during at least two vertiginous attacks:
- Migrainous headache
- Visual or other aura symptoms
- Other causes ruled out by appropriate investigations
Vestibular symptoms include rotational vertigo or another illusion of motion of self or environment. Symptoms may be spontaneous, positional, or provoked or aggravated by head motion.
Vestibular symptoms are "moderate" if they interfere with but do not prohibit daily activities, and "severe" if patients cannot continue daily activities.
Criteria for probable migrainous vertigo are also proposed.
Evidence of vestibular dysfunction in migraine
A number of clinical series report a high prevalence of vestibular signs and symptoms in patients with migraine, suggesting that vestibular involvement may be an integral feature of migraine.
- Among series of patients with migraine who present for treatment of headache, a history of episodic vertigo is reported by 20 to 33 percent. The lifetime prevalence of vertigo was estimated in one general population survey to be less than 8 percent.
- One-half to two-thirds of migraineurs suffer motion sickness. This prevalence is probably two to five times greater than in the general population.
- A number of studies have performed vestibular laboratory tests in patients with migraine. A literature review that summarized many of these studies reported a 25 percent prevalence of peripheral vestibular abnormalities in migraine patients. Many of these patients did not suffer from clinical vertigo. Nonlocalizing vestibular signs and signs suggestive of central vestibular dysfunction were also common but also quite variable between studies.
- The previous studies refer to findings in migraine patients in a symptom-free period. Twenty patients examined during acute migrainous vertigo revealed findings consistent with central vestibular dysfunction in 10 and peripheral dysfunction in 3; in 7 the site of involvement was unclear.
- Migrainous vertigo may represent the adult equivalent of benign paroxysmal (recurrent) vertigo of childhood. Long-term follow-up of children with this entity suggests that most will go on to develop migraine later in life. This disorder is accepted by the International Headache Society (IHS) as a migraine equivalent.
- The association of vertigo and migraine is specific, not extending to other headache syndromes. In one series comparing unselected groups of migraine and tension-type headache patients, migraineurs were more likely than tension-type headache sufferers to report episodic vertigo (27 versus 8 percent). In another study, stabilometric evaluation revealed evidence of interictal vestibular dysfunction in a group of 21 patients with migraine; patients with tension-type headaches had findings that were similar to controls.
- Auditory symptoms also occur during migraine attacks. The most common is sensitivity to sound, or phonophobia, which occurs in two-thirds of patients. A smaller number of patients report aural fullness, decreased hearing, or tinnitus during their migraine attacks. Both sudden, permanent as well as episodic, fluctuant, low-frequency hearing loss (similar to that seen in Meniere disease) has been attributed to migraine, but in general the prevalence of baseline hearing loss is low in patients with migraine.
Migraine in patients with vertigo
Migraine also appears to be more prevalent than otherwise expected in patients with episodic vertigo. In a series of 200 consecutive patients presenting to a dizziness clinic, the lifetime prevalence of migraine was higher compared with an age- and sex-matched control group from an orthopedic clinic (38 versus 24 percent). However, the dizziness was attributed to migraine in only 14 patients.
One study surveyed family members of 24 patients with chronic recurrent attacks of vertigo with no identified auditory or neurologic pathology who had also reported a family history of vertigo. Half of relatives reported symptoms meeting criteria for migraine compared with 2 percent of unrelated spouses.
The pathophysiology of migraine is incompletely understood. This is discussed separately.
The mechanisms underlying migrainous vertigo are also incompletely understood. The wide spectrum of clinical and laboratory features of vestibular dysfunction in migraine discussed above suggests a heterogeneous pathophysiology. Many potential mechanisms are proposed; these are not mutually exclusive.
- Migraine aura — In some patients, migrainous vertigo may represent a typical migraine aura. The mechanism of migraine aura is understood to be a wave of neuronal and glial depolarization, so-called cortical spreading depression. Migrainous vertigo may be a "brainstem aura" due to noncortical spreading depression. Alternatively, true cortical spreading depression may, via direct projections from the posterior parietal cortex, influence vestibular nuclei.
Migraine aura is likely to be the mechanism when the vestibular symptoms share features similar to other migrainous auras: a typical time duration of 5 to 60 minutes, accompanying positive visual phenomena and subsequent migraine headache. However, this mechanism is probably unlikely in most cases. In different case series, less than one-third of patients with migrainous vertigo had vestibular symptoms meeting this description.
- Trigeminovascular system — Longer-lasting vestibular symptoms may stem from a process that parallels the headache phase of migraine but does not necessarily include headache. One mechanism proposed for migraine headache includes a primary brainstem event involving the trigeminal nucleus. Stimulation of the trigeminal neuron produces vasodilation and antidromic release of inflammatory neuropeptides into the dural circulation, potentially causing headache. Vestibular receptors exist to at least one of these peptides (calcitonin gene-related peptide).
Reciprocal connections between the vestibular nuclei and the trigeminal nucleus caudalis and other brainstem nuclei linked to migraine may link vestibular and trigeminal processes in other ways as well. Activation of central vestibular nuclei can alter monoaminergic activation that in turn modulate migrainous symptoms and pain pathways.
- Labyrinthine sensitivity — Patients with migraine have a reduced threshold to numerous sensory stimuli, including motion sickness, as well as lights, sound, tactile stimuli, and smells. They are more likely to exhibit subclinical vestibulocerebellar abnormalities.
- In one study, patients with migraine were more sensitive than control subjects to optokinetic stimulation inducing motion sickness. This stimulation also induced allodynia and photophobia in migraineurs.
Labyrinthine sensitivity may be an integral feature of individuals predisposed to migraine, or this may result from injury to the labyrinth, perhaps because of migraine-induced ischemia.
- Channelopathy — The vestibular symptoms suffered by some patients with migraine may arise from a channelopathy. One channelopathy, episodic ataxia type 2 (EA-2), manifests clinically with episodic vertigo. Half of patients with this disorder have migraine. Another disorder, familial hemiplegic migraine (FHM), is associated with a genetic abnormality of the same calcium channel. Both of these disorders have been linked to a mutation on chromosome 19p.
Other kindreds with apparently dominantly inherited syndromes which include both migraine and episodic vertigo have been described. While a similar ion channel genetic defect is suspected, a gene locus in these families is not yet identified; linkage analysis ruled out a linkage to the 19p locus associated with EA-2 and FHM.
A channelopathy may cause a local rise in extracellular potassium. This may lead to either the spreading depression of migraine and/or a paroxysmal osmotic disequilibrium that in turn may yield endolymphatic hydrops and/or hyperkalemic toxicity to the inner hair cells.
- Migraine-related ischemia — Migraine appears to be a risk factor for ischemic stroke, perhaps related to vasospasm. (See "Headache, migraine, and stroke" .) Migraine-induced ischemia of the inner ear may lead to cochlear and labyrinth injury [ 38,39 ]. Vascular injury may cause a frank infarction of the labyrinth; less severe ischemic injury can cause endolymphatic hydrops and benign positional vertigo.
- Endolymphatic hydrops — Endolymphatic hydrops, a distention of the membranous, endolymph-containing portions of the labyrinthine system, is the pathologic lesion underlying Meniere disease. Some suggest that migrainous vertigo and Meniere disease are associated, while others suggest that the overlap in presentation may lead to misdiagnosis.
The attacks of vertigo that characterize Meniere disease and migraine are similar in their characteristic duration. One study observed that attacks of vertigo in patients with Meniere disease have a migrainous feature (headache, photophobia, or visual aura) in 45 percent of patients. This study also reported that patients with Meniere disease had an increased lifetime prevalence of migraine compared with controls (56 versus 25 percent).
It has been suggested that a channelopathy causing migraine could also cause an osmotic disequilibrium in the inner ear, resulting in endolymphatic hydrops. Alternatively, migraine-associated ischemia could damage the labyrinth and produce endolymphatic hydrops on that basis.
- Benign paroxysmal positional vertigo — Migraine has also been linked to benign paroxysmal positional vertigo (BPPV). Among a series of 247 patients, migraine was three times more common in patients with idiopathic BPPV compared with those with secondary BPPV. Migraine was present in more than half of patients who developed BPPV under the age 50 years. Significant minorities of patients with migrainous vertigo have clinical episodes that are similar to those of BPPV, ie, brief, positionally-induced attacks of vertigo. It is hypothesized that migraine-induced ischemia to the utricle may cause release of otoconia into the semicircular canal.
- Migraine trigger — Another hypothesis is that vertigo may act as a migraine trigger. Evidence for this is somewhat limited but includes a report of three individuals who had migraine attacks shortly after caloric testing. In another observational study based in a neuro-otology clinic, nearly half of migraine patients who underwent vestibular testing experienced a migraine within 24 hours of testing, compared with 12 percent of patients without a migraine history. The 24-hour incidence of migraine in a control group of individuals with a migraine history who did not receive vestibular testing was 5 percent.
CLINICAL AND EPIDEMIOLOGIC FEATURES
Most patients with migrainous vertigo have vestibular symptoms without other neurologic symptoms. This distinguishes migrainous vertigo from basilar-type migraine, in which at least two symptoms from the posterior circulation are required.
A population-based study in Germany, screening a representative sample of the population using the criteria described above, estimated a lifetime prevalence of migrainous vertigo of approximately 1 percent. While two-thirds of patients identified as having migrainous vertigo had consulted a clinician regarding this problem, only 20 percent were given that diagnosis.
Clinical case series have described features of migrainous vertigo. In the absence of a diagnostic test, most investigators, but not all, have used the clinical criteria shown in the Table, either implicitly or explicitly. Referral bias likely influences some of the findings, as these series are based in neurotology clinics.
- The duration of an episode of migrainous vertigo js variable and can last seconds to a few minutes (<15 percent), hours (30 percent), or days (25 percent), with most lasting at least several hours.
- The vertigo may occur with or without the patient’s typical migraine headache.
- Episodes may occur several times a day or only a few times each year.
- One or more nonheadache migraine symptoms (photophobia, phonophobia, visual aura) often occur during the episodes of vertigo. Nausea and vomiting are also frequent, but nonspecific, complaints. Other commonly associated symptoms include: head motion intolerance (a sense of motion and nausea provoked or aggravated by head movement), visual vertigo (dizziness provoked by opticokinetic stimuli such as moving visual scenes, ie, traffic or moving trains), and non-vertiginous “dizzy” symptoms such as lightheadedness, imbalance, or “boat-like” rocking.
- On laboratory testing, interictal vestibular signs (spontaneous, positional, or gaze-evoked nystagmus, abnormal vestibuloocular reflex) are common, in 53 to 66 percent of patients.
- Auditory symptoms, other than phonophobia, are not common in patients with migrainous vertigo, but hearing loss, aural fullness, and tinnitus are reported in a few patients.
- Women tend to predominate in case series (60 to 83 percent). This gender ratio is similar to that seen in migraine.
- Migrainous vertigo is diagnosed more frequently in children than adults (35 versus 6 percent). In adult case series, the mean age of onset of vertigo in migraine is approximately 40 years old. However, in one series, a first attack occurred as late as 72 years.
- While some note that migraine headache precedes the development of migrainous vertigo, often by several years, it seems plausible that diagnostic criteria influence this finding. The opposite order of symptom appearance occurs in those who have benign paroxysmal vertigo of childhood and later develop migraine headaches.
DIFFERENTIAL DIAGNOSIS — The differential diagnosis of patients with vertigo is extensive. These disorders are discussed separately. In general, clinical features of the vertigo, especially the duration of attacks, help distinguish between diagnostic entities.
Major considerations in the differential diagnosis of migrainous vertigo are those disorders that produce vertigo with a similar tempo of symptoms. These most often include Meniere disease and vertebrobasilar transient ischemic attack.
- In general, Meniere disease is distinguished from migrainous vertigo by symptoms of ear fullness or pain preceding the attack or at attack onset, and accompanying tinnitus and/or hearing loss during the episode. These symptoms are not typical or prominent in migrainous vertigo. However, in rare patients with Meniere disease, audiologic symptoms may be absent. Audiometry in these patients may be helpful, by showing the typical low-frequency hearing loss. In some patients, treatment trials for either Meniere disease or migraine may be useful for differentiating the two syndromes.
- Brainstem ischemia generally produces other symptoms (numbness, weakness, diplopia, dysarthria, dysphagia) in addition to vertigo. It is debated whether vertigo without brainstem symptoms can occur with transient vertebrobasilar ischemia. Certainly, brainstem infarctions producing restricted injury to the vestibular pathways and vertigo alone as a symptom are reported. Given the prognostic implications, it seems reasonable to consider the diagnosis, especially in older patients or those with vascular risk factors who do not have a history of vertigo attacks. Magnetic resonance imaging (MRI) with diffusion-weighted imaging may be helpful if performed in close temporal proximity to the event, but its sensitivity for transient ischemia is less than 50 percent; magnetic resonance angiography (MRA) may demonstrate arterial occlusive disease in the posterior circulation.
There are no conclusive diagnostic tests for migraine or migrainous vertigo. Given the uncertainties surrounding this clinical entity, it should be considered a diagnosis of exclusion.
- If a first episode lasts longer than a few minutes, patients should undergo magnetic resonance imaging (MRI) with diffusion-weighted imaging and magnetic resonance angiography (MRA) of the posterior circulation to exclude the possibility of vascular or structural brainstem disease.
- Audiometry is advised to evaluate subclinical hearing loss and possible Meniere disease. In some cases, treatment trials for either migraine or Meniere disease can help to differentiate between these disorders.
- Patients with very brief attacks of vertigo that are positionally induced should be evaluated for benign paroxysmal positional vertigo.
The efficacy of therapy for migrainous vertigo is not well studied.
There are no randomized, controlled studies. Most of the data come from case reports and retrospective reviews. From these reports, the following observations emerge:
- Acute migraine treatments such as ergotamine and triptans may offer benefit. In one observational study, sumatriptan was reported to be particularly efficacious in improving vertigo. A pilot trial of zolmitriptan for migrainous vertigo found a non significantly improved response rate with treatment versus placebo (38 versus 22 percent). Low enrollment because of infrequent or brief attacks limited the power of this study.
- Others use vestibular suppressants to treat acute attacks of migrainous vertigo. These agents include benzodiazepines, antiemetics, antihistamines, and anticholinergic agents.
- Patients with frequent episodes of migrainous vertigo may find relief with approaches used in migraine prevention. In a retrospective chart review of 81 patients with migraine-related vertigo, a treatment approach that included avoidance of migraine dietary triggers, with or without migraine prophylactic therapy using tricyclic antidepressants, beta blockers, or calcium channel blockers, produced substantial symptom relief in greater than 50 percent of patients. These patients experienced an equal reduction in headache and vertigo. Gabapentin , lamotrigine , valproate , and topiramate have also been used anecdotally to treat migrainous vertigo, and in a small randomized pilot study, rizatriptan prevented the development of motion sickness symptoms in patients with migrainous vertigo.
- In one case series of patients with migrainous vertigo who were treated with abortive and/or prophylactic medication for migraine, there was a correlation between the efficacy of treatment for vertigo with the efficacy of treatment for headache.
- Vestibular physical therapy was associated with improved symptoms and disability in an uncontrolled series of 14 patients with migrainous vertigo.
- Acetazolamide is effective in preventing attacks in episodic ataxia type 2. While not widely used in the treatment of either migraine or vertigo, some authors report that it is effective in treating their patients with migrainous vertigo.
In the absence of definitive data, a trial of therapies used to treat acute migraine or to prevent migraine seems reasonable in patients with recurrent episodes of migrainous vertigo, especially if vestibular suppressants are not effective. Indications for prophylactic therapy should mirror those for migraine headache, which consider the frequency, duration, and disabling nature of the attacks.
SUMMARY AND RECOMMENDATIONS
- Migrainous vertigo is a term used to describe episodic vertigo in patients with a history of migraines or with other clinical features of migraine (photophobia, phonophobia, visual aura, etc). Clinical criteria are proposed but are not universally accepted.
- There is diverse evidence that the vestibular system is affected in patients with migraine. The varied clinical and epidemiologic findings and proposed pathophysiologic mechanisms suggest that migrainous vertigo is a heterogeneous condition.
- There are no confirmatory tests for migrainous vertigo, which is a diagnosis of exclusion. Other disorders, specifically Meniere disease and structural and vascular brainstem disease, must be excluded in most patients.
- We suggest treatment trials with either symptomatic or prophylactic therapies used in migraine for patients with symptoms characteristic of migrainous vertigo in whom other diagnoses have been excluded.