Migraine-Associated Vertigo

Etiology

Concrete evidence regarding the absolute etiology of VM remains limited. Genetics are significant factors influencing an individual's susceptibility to migraines, including VM. Recent genome-wide association studies have pinpointed specific genetic variants associated with susceptibility. Noteworthy variants include rs2651899 in the PRDM16 gene, rs10166942 in the TRPM8 gene, and rs11172113 in the LRP1 gene.[6] 

Genetics likely influence VM, as evidenced by a recent study revealing an autosomal dominant (AD) inheritance trait linked to gene locus 5q35 in a 4-generation family line. The majority of this family demonstrated headaches followed by vertigo within 15 to 20 years after the onset of migraine headaches. Other studies have reported links to a region on chromosome 11q or 22q12.[7]

Interestingly, within the family afflicted by familial VM, some members experienced standard migraines, while others suffered from vestibular migraines or benign paroxysmal vertigo of childhood. This diversity in symptoms suggests phenotypic heterogeneity; thus, the inheritance pattern for VM is autosomal dominant with variable penetrance.[6]

Many peripheral vestibular disorders are seemingly associated with VM, including Meniere syndrome and benign paroxysmal positional vertigo (BPPV).[8] Additionally, these associations between VM and peripheral vestibular disorders highlight the complex interplay between migraine-related symptoms and disturbances in the inner ear's balance mechanisms.

Epidemiology

Migraine affects approximately 12% of the population, with a prevalence of 6% in adult men and 18% in adult women. VMs occur in up to 1% of the population, representing the most frequent cause of episodic migraine.[9][10]

VMs are predominantly observed in midlife, particularly among females, showing a 5:1 female-to-male preponderance. The mean age of onset of vertiginous symptoms occurs around 37 years for females and 42 years for males. Migraines typically precede the onset of vertigo, with headaches beginning at the average age of  28, while dizziness manifests around 49.[9][11]

Pathophysiology

Migraine, a prevalent yet complex disorder, has been the subject of varied and debated pathophysiological theories. Traditionally rooted in the vascular theory, the pathophysiology of migraines has evolved into a contemporary neuronal theory. Cortical spreading depression (CSD) electrically represents the aura of migraines, while the trigeminal vascular system (TVS) serves as the anatomical substrate for headaches.[12] 

The vestibular symptoms in migraines might not fit the conventional aura pattern due to their duration ranging from seconds to days, which is not typical for migraine aura. However, the wave of CSD may extend to the vestibular cortex or the brainstem vestibular nuclei, potentially involving the TVS in VM. The vertigo experienced in VM  might be elucidated by reciprocal connections between the trigeminal nucleus caudalis and the vestibular nuclei.[6][13]

Nevertheless, the precise pathophysiology of VM is still controversial, with limited consensus among researchers. Various theories propose that vestibular symptoms may be an aura, a symptom linked to a headache, or due to actual peripheral vestibulopathy. In 2011, Eggers et al suggested that vertigo in VM might be best categorized as an associated phenomenon rather than a typical aura.[11]

Another theory involves the concept of "kindling." Similar to how epileptic seizures might decrease the threshold for future seizures, a comparable mechanism is considered for VM. This theory suggests that individuals with VM become sensitized to stimuli, such as motion in the visual field, which could potentially trigger recurrent VM symptoms.[14]

Lastly, a study demonstrated that caloric testing could trigger migraines in certain individuals. In this study, 39 participants with a migraine history underwent caloric testing. Within 24 hours, 19 individuals developed their typical migraine symptoms. Notably, 47% of those who developed a migraine within 24 hours did so during testing. The study utilized a matched control group, and only 1 of 21 individuals developed a migraine within the initial 24-hour period after testing.[15][16] This puzzling finding suggests a link between peripheral vertigo and the triggering of migraines or migraine-related symptoms.

History and Physical

Thirty percent of individuals diagnosed with VM may not have a history of headaches.[17] Common complaints include acute episodes of vertigo lasting seconds to days, dizziness, imbalance, and spatial disorientation. Other symptoms may include lightheadedness, a swimming sensation, heaviness in the head, a rising sensation, tingling, a rocking sensation, and increased motion sickness susceptibility. Additionally, transient fluctuating hearing loss, aural fullness, tinnitus, and mild sensorineural hearing loss on audiograms are common.

Defining vertigo involves the patient experiencing a sensation of motion when there is no actual movement or an altered sensation despite normal motion. In a VM, the sensation is often described as a "to-and-fro" motion, which can complicate diagnosis due to its variability in duration, mimicking other causes of vertigo. Vertigo and headaches seldom occur concurrently; the simultaneous manifestation of both symptoms is a rare occurrence. Moreover, there is no consistent pattern of vestibular symptoms during headache episodes.[18][19][20] 

Patients typically seek initial medical help from primary care providers, who often attempt symptomatic treatment. If symptoms persist or recur, patients often seek consultation with head and neck specialists, with Meniere disease being a frequent consideration as the primary differential diagnosis. However, when patients do not demonstrate low-frequency hearing impairment on audiograms or do not respond to conventional Meniere disease treatments, the final diagnosis of VM is made.

Vestibular migraines are persistent and may be linked to women's menstrual cycles. Studies indicate that nearly half of those diagnosed with probable VM progress to definite VM according to the previously mentioned Neuheuser criteria. Another study showed that almost 30% experienced more frequency of attacks over a 9-year observation period, while around 50% experienced a reduced attack frequency. Nearly 90% of individuals with VM continued to report vertiginous attacks after nine years. Cochlear complaints such as aural fullness, tinnitus, and hearing loss during vertigo spells appear more common over time.[21]

Evaluation

A comprehensive history is imperative, given the absence of specific pathognomonic imaging studies or available tests consistent with VM. Nevertheless, specific nonspecific findings have been noted in some studies. For instance, magnetic resonance imaging (MRI) has revealed consistent findings associated with general migraines. White matter hyperintensities are observed 4 times more frequently in patients with VM compared to age and gender-matched controls.[22] Although some functional neuroimaging studies have shed light on general migraine pathophysiology, there is limited research specifically focused on VM.

Vestibular testing and neurotologic exams typically yield nondiagnostic abnormalities in individuals diagnosed with isolated probable or definite VM. It is important to note that individuals with comorbid Meniere syndrome or BPPV are more likely to exhibit abnormal test results.[11]

Another study has indicated a higher occurrence of unilateral canal paresis during caloric testing and vestibular hyporesponsiveness or hyperresponsiveness in vestibular migraine patients.[21] One study suggests abnormal findings in the sacculocollic pathway (cervical vestibular evoked myogenic potentials [cVEMP]) while ocular VEMP (oVEMP) results remained normal in patients with VM compared to healthy controls; however, these findings have not been duplicated.[23] Moreover, these observed abnormalities are not exclusive to VM.

Ultimately, the diagnosis of VM relies primarily on clinical assessment, particularly emphasizing the significance of a patient's medical history and family history regarding migraines and history of childhood vertigo. The diagnosis of VM is not made until other peripheral vestibular disorders are ruled out.[4]

Treatment / Management

Current management of a vestibular migraine consists of conventional management techniques as there is no widely accepted specific treatment for this condition.[14][23] Additionally, convincing patients of this diagnosis can be difficult, potentially causing treatment delays or absence of treatment. This challenge is based on the fact that vertiginous symptoms often occur independently of headaches, making it a complex connection for practitioners and patients to comprehend.[24][25](B3)

Despite isolated reports indicating limited benefits during acute vertigo attacks, triptan therapy is generally not considered an effective treatment for VM based on the findings from Sargent's research.[18][26][27] Cochrane database review also showed no convincing evidence of the efficacy of triptans in relieving the symptoms of vertigo in VM.[28] Triptans and calcium channel blockers (CCBs) have proven ineffective in shortening aura or preventing headaches in general migraines.[25] However, their effectiveness, specifically in VM, has not been studied. Therefore, the current recommendation for acute VM is to use antiemetic and antivertigo therapies, including benzodiazepines.[18] (A1)

Noninvasive vagal nerve stimulation (nVNS) is a new treatment modality for acute abortive treatment of VM. This method, self-administered by the patient without any implantation procedure, has a well-established safety profile and minimal adverse effects. Preliminary evidence indicates promise in managing acute VM.[29]

Current recommendations for VM prevention focus on lifestyle adjustments, such as avoiding dietary triggers, improving behaviors, and instilling good sleep hygiene.[27] A retrospective study revealed that caffeine cessation led to symptomatic improvement in 15% of the tested patients with VM. However, these improvements were incomplete; many patients required additional medical therapy. The study also found that 75% of those with VM experienced substantial relief through lifestyle changes combined with nortriptyline or topiramate treatment without further intervention. Specifically, nortriptyline provided relief for 46% of patients, while topiramate offered relief for 25% in the retrospective analysis.[30] In a separate prospective study, topiramate (50 to 100 mg/d) reduced the frequency and severity of vertigo and headaches.[31](A1)

In a 2017 randomized controlled trial by Liu et al, the efficacy and safety of venlafaxine, flunarizine, and valproic acid in preventing VM was demonstrated. Each treatment exhibited unique properties; for instance, venlafaxine proved advantageous in addressing emotional symptoms. Additionally, both venlafaxine and valproic acid were more effective than flunarizine in decreasing the frequency of vertiginous attacks. However, valproic acid appeared less effective than venlafaxine and flunarizine in reducing vertigo severity.[32]

The American Headache Society and American Academy of Neurology recommend several therapies for managing episodic migraines, including butterbur, divalproate, metoprolol, propranolol, timolol, and topiramate.[33] While only topiramate has been specifically evaluated for treating VM, clinicians could consider these medications as potential treatment choices. Other possibilities include amitriptyline and CCBs.[24][26] Clinicians may also consider other comorbidities with VM, tailoring therapies to address multiple illnesses. An example includes using nortriptyline to treat concomitant anxiety, while topiramate or propranolol could be options for associated headaches or hypertension.(A1)

A recent study shows the effectiveness of monoclonal antibodies targeting calcitonin gene-related peptide (CGRP) in treating VM, with the authors suggesting early initiation of this treatment for patients with VM. CGRP inhibition may be one of the most effective preventive therapies available.[34] However, significant challenges associated with CGRP as a treatment option are its high cost and patients' difficulty gaining insurance approval to receive these medications. 

Physiotherapy may play a role in addressing associated sequelae of VM, such as anxiety, visual dependence, and loss of confidence.[25] Individuals with interictal imbalance symptoms could consider vestibular rehabilitation therapy a potential treatment modality.[35](B2)

Currently, there are no recommended surgical interventions for VM, as these may exacerbate vertigo associated with Meniere disease. Patients diagnosed with VM are encouraged to explore noninvasive and pharmacological treatments under the guidance of their healthcare providers, focusing on symptom management and improving overall quality of life.

Differential Diagnosis

A differential diagnosis of VM includes the following:

Meniere Syndrome

The association between Meniere syndrome and VM appears complex. Many tertiary otolaryngology centers routinely conduct clinical evaluations for patients experiencing dizziness or vertigo. Acknowledging selection bias, a study conducted at one such center demonstrated that nearly 30% of patients with Meniere syndrome might also exhibit VM, while an additional 30% did not meet VM criteria but did demonstrate some migraine-like qualities.[36]

Another study showed connections between Meniere syndrome and VM. Within 9 years, 13% to 18% of individuals diagnosed with probable or definite VM developed bilateral, low-frequency sensorineural hearing loss. Interestingly, 7% to 11% exhibited cochlear symptoms meeting the criteria outlined by the American Academy of Otolaryngology, Head and Neck Surgery (AAO-HNS) for bilateral Meniere syndrome.[21][37]

In 2013, Wise and Sargent reported that individuals experiencing simultaneous migraine headaches with intractable Meniere syndrome experienced worse quality of life-related surgical outcomes than those with intractable Meniere syndrome alone. These observations were made following endolymphatic sac decompression procedures for intractable Meniere syndrome.

The possibility of coexisting conditions cannot be overlooked, and it is essential to consider this factor for diagnostic evaluation and treatment planning. The overlapping symptomatology between these conditions can create diagnostic confusion, potentially causing uncertainty and distress for the patient.

Benign Paroxysmal Positional Vertigo (BPPV)

The connection between BPPV and VM is complicated and not well understood. Studies have indicated that individuals with BPPV successfully managed with the Epley maneuver have a higher incidence of motion sickness or migraine history than the general public.[38]

Moreover, a combination of symptoms, including vertigo, nausea, and headaches, accompanied by sustained nystagmus on positional testing that dissipates when the patient is symptom-free, suggests a diagnosis of VM.[39] Additionally, research has proposed an association between probable or definite VM diagnoses and atypical positional nystagmus or vertigo.[37] Despite these potential associations, it is crucial to rule out singular canal or multiple canal cupulolithiasis, as these conditions can significantly trigger vertigo-associated migraines.

Migraine Anxiety-Related Dizziness (MARD) 

MARD, characterized by recurrent dizziness leading to debilitating anxiety, necessitates careful consideration. Diagnosis involves identifying symptoms related to anxiety, migraines, and vestibular disturbances. Addressing all these aspects, including anxiety management, migraine treatment, and balance disorder interventions, is necessary.[19][40]

Other Important Considerations

An estimated 50% of children with vertigo are related to migraines. Among children aged 2 to 6, benign paroxysmal vertigo of childhood is the most common cause of vertigo, with a prevalence of approximately 2.6% between the ages of 5 and 15.[41] This condition usually presents with brief episodes of vertigo or dizziness lasting seconds to minutes, nystagmus, postural imbalance, nausea, or vomiting, with the child returning to their baseline state between episodes. Many children tend to outgrow this condition, experiencing relief from its symptoms after their sixth birthday.

Chronic subjective dizziness (CSD) is characterized by chronic instability or dizziness without vertigo. Individuals with CSD often exhibit hypersensitivity to motion stimuli and have poor tolerance of visual stimuli or precision visual tasks. To diagnose CSD, these symptoms must persist for 3 months or longer. CSD is frequently found to coexist with other recurrent vertigo disorders.[42]

Over an extended follow-up period, several diagnoses commonly replace VM. These include Meniere syndrome, BPPV, psychogenic dizziness, and spinocerebellar ataxia. Before confirming a diagnosis of VM, it is essential to rule out episodic ataxia type 2 and transient ischemic attacks.[18]

Prognosis

The prognosis for these patients remains uncertain; however, anecdotal reports suggest that recurrences are frequent. This uncertainty emphasizes the imperative for ongoing research and the development of personalized management strategies to address the recurrent nature of this condition effectively.

Complications

Clinical observations have revealed diverse degrees of disability and responsiveness to treatments within the population with VM. Individualized treatment approaches, considering the unique symptom profiles and responses to therapies, are crucial to enhancing the quality of life for individuals affected by VM.