Episodic Spontaneous Dizziness (Neuro-otology April 2021)

Educational Objectives

The goal of this program is to improve management of neuro-otologic disorders. After hearing and assimilating this program, the clinician will be better able to:

1. Identify common causes of episodic spontaneous vertigo.
2. Recognize key characteristics of disorders that cause episodic spontaneous vertigo.
3. Optimize the use of diagnostic testing in patients presenting with episodic spontaneous vertigo.

Summary

Overview: When patients report recurrent, untriggered episodes of vestibular symptoms, a careful history guides the differential diagnosis; although many neurologists do not have expertise in evaluating and treating vestibular disorders, their skill in history gathering and physical examination qualifies them to identify and manage most conditions that cause episodic spontaneous dizziness; expensive tests may not be needed; in fact, ordering inappropriate tests may lead to diagnostic confusion.

Inquiring about symptoms: Patients typically have episodes of symptoms over a defined period and feel well between episodes; therefore, findings on bedside examination typically are normal; asking patients to describe what they mean by “dizziness” may lead to premature diagnostic closure, because the descriptions often are inconsistent, and patients are unreliable in their use of terms and the features they describe; words used by patients or clinicians have clear meanings only when used in context; the initial focus should be on defining the temporal profile, frequency, and duration of episodes; also focus on triggers of episodes, the circumstances in which they occur, and accompanying symptoms and coexisting conditions.

Common causes: Include vestibular migraine, Ménière disease, vertebrobasilar transient ischemic attacks (TIAs), vestibular paroxysmia, and conditions that cause episodic vestibular symptoms (eg, panic disorder, delayed orthostatic hypotension, cardiogenic dizziness, hypoglycemia, toxic or metabolic disorders).

Association between migraine and vestibular symptoms: Migraine and dizziness are common in the general population; epidemiologic data suggest that, compared with the general population, dizziness is more common in patients who have migraine, and migraine is more common in patients who have episodic vestibular symptoms; in patients who have migraine, the incidence of motion sickness (induced by motion or visual stimuli) is high compared with that in the general population.

Vestibular migraine: Recurrent episodes of vestibular symptoms that are secondary to migraine; the International Headache Society and the Bárány Society jointly developed clinical diagnostic criteria for vestibular migraine; there is no specific biomarker; symptoms of several clinical syndromes overlap, and there are no specific diagnostic tests for some of those syndromes; the pathophysiology is likely heterogeneous; vestibular symptoms may include an aura of cortical spreading depression or a brainstem aura; these symptoms may be related to transient changes in neurotransmitters in the brainstem or inner ear; changes in the inner ear may explain the overlap with symptoms of Ménière disease; large epidemiologic studies in Germany and the United States found that the estimated lifetime prevalence of vestibular migraine is 1% to 2.7% and that vestibular migraine is the most common cause of spontaneous, recurrent episodes of nontriggered and nonpositional vertigo.

Diagnostic criteria: Codeveloped by the International Headache Society and the Bárány Society; these criteria are stratified as definite or probable vestibular migraine; in most cases, failure to meet the full criteria is attributable to lack of clarity about the relationship between headache or migrainous symptoms and vestibular symptoms; according to the criteria, diagnosis requires recurrent attacks of moderate or severe vestibular symptoms in a patient with a current or prior diagnosis of migraine (with or without aura); in addition, at least half of the vestibular episodes must be accompanied by at least one migrainous symptom (eg, headache, photophobia, phonophobia, visual aura); the duration of vestibular symptoms ranges from 5 minutes to 3 days.

Treatment: Nonpharmacologic strategies for preventive management include providing education and ensuring adequate sleep and exercise; vestibular suppressant or antiemetic agents are used to treat acute vestibular episodes that last 30 minutes or longer; an ongoing multicenter randomized controlled trial is evaluating the effectiveness of rizatriptan in aborting or shortening vestibular symptoms; only a few placebo-controlled trials to assess or compare the efficacy of prophylactic medications have been performed; treatment choices generally are based on patient comorbidities and profiles of adverse effects.

Patients with episodic spontaneous dizziness: In patients who have recurrent, episodic, spontaneous vestibular symptoms, vestibular migraine is the most common diagnosis; the condition is underrecognized and undertreated; it is the most treatable of these conditions.

Ménière disease: An inner ear disorder attributed to endolymphatic hydrops (difficult to identify on MRI; its relationship with the clinical syndrome is unclear).

Signs and symptoms: Often overlap with those of vestibular migraine; patients typically present with unilateral auditory symptoms (eg, fluctuating sensorineural hearing loss in the low to mid frequencies, roaring or rushing tinnitus, muffled hearing, pressure in the affected ear); these auditory symptoms may be present hours or days before an attack of vertigo; however, after a short time, the auditory and vestibular symptoms typically coexist; the duration of intense vertigo ranges from 20 minutes to 12 hours; additional symptoms may include nausea, vomiting, imbalance, diaphoresis, diarrhea, and headache.

Differentiation from vestibular migraine: Patients who have Ménière disease may have a strong family history of migraine, and patients who have vestibular migraine commonly report minor auditory symptoms (eg, tinnitus, fullness in the ear, bilateral or unilateral subjective loss of or distorted hearing); vestibular migraine is not typically associated with sensorineural hearing loss; therefore, performing audiography close to the time of an attack (while the patient is experiencing symptoms) is helpful in diagnosis; sensorineural hearing loss in temporal proximity to an attack and subsequent recovery suggest a diagnosis of Ménière disease (not vestibular migraine).

Treatment: Other conditions should be ruled out first; comorbidities that may cause symptoms should be identified; noninterventional management strategies include a diet low in sodium and caffeine, diuretic agents, and consideration of interventional procedures by an otolaryngologist or neuro-otologist (eg, intratympanic injection of steroids or gentamicin, ablative procedures) to reduce attacks of vertigo; if the diagnosis may be either migraine or Ménière disease, aggressive treatment of possible migraine and vestibular migraine may help avoid the need for interventional procedures in the inner ear; a prophylactic approach to treatment of migraine may be considered; further management then may be guided by effects of this treatment on headache and vestibular symptoms.

Vertebrobasilar transient ischemic attacks: Patients often present to the emergency department with their first acute attack of vertigo, nausea, and imbalance; differentiating acute peripheral vestibulopathy (eg, vestibular neuritis) from a central cause (eg, acute cerebellar or brainstem stroke) relies on physical examination (eg, head impulse testing, features of nystagmus, skew deviation); patients who have vertebrobasilar TIAs often present between episodes; therefore, diagnosis typically is based on a description of symptoms and associated risk factors; presentation with isolated, recurrent attacks of spontaneous vertigo is uncommon in patients with TIAs; however, TIA should be considered in patients who are older, have multiple vascular risk factors, and have had multiple episodes over several weeks; data suggest that, in patients who have a completed vertebrobasilar stroke, the most common preceding TIA-related symptom is vertigo (often an isolated symptom); the occurrence of episodes of vertigo combined with diplopia, dysarthria, facial numbness, and limb clumsiness is a more obvious indication of TIA in the brainstem; compared with TIAs in other areas (eg, carotid artery), the duration of symptoms in vertebrobasilar TIA is often longer (possibly as long as 2 hours); among patients who present to the emergency department with persistent vertigo, a missed diagnosis of stroke is most likely to be the cause in younger patients who have no vascular risk factors.

Vestibular paroxysmia: Characterized by recurrent, brief (less than 1 minute), typically spontaneous attacks of vertigo or other vestibular symptoms that are unprovoked in any position (they may be triggered by changes in the position of the head); the condition is associated with microvascular compression of the vestibulocochlear nerve; a response to carbamazepine or oxcarbazepine may be used as a diagnostic criterion; the relationship between the condition and microvascular compression is difficult to study; in many asymptomatic individuals, a vascular loop against the vestibulocochlear nerve is present; conversely, a loop is not always present in individuals who have the clinical syndrome; occasionally, the condition is caused by other structural lesions (eg, tumors); time-locked auditory symptoms are reported by a subset of patients; patients often respond to carbamazepine, oxcarbazepine, or lacosamide; doses and medications may be adjusted to alleviate adverse effects; in the majority of patients, surgery is not performed.

Take-home messages: In patients who have recurring vestibular symptoms, the most important initial step is to define the timing, potential triggers, and frequency and duration of symptoms, and to clarify what patients describe as vertiginous episodes; the relative frequency of attacks over time also should be considered; obtain an adequate history of auditory symptoms or conditions and determine whether those symptoms suggest a diagnosis of Ménière disease or need for audiography; patients who have other conditions that cause hearing loss (eg, vestibular schwannoma) may present with episodic vestibular symptoms; vertebrobasilar TIAs should be considered in patients at high risk; in patients who have episodic vestibular symptoms and vestibular migraine, common comorbidities that should be considered include conditions that cause persistent daily nonvertiginous dizziness; as many as one-third of patients who have episodic symptoms of vestibular migraine for several years develop recurrent attacks of vertigo or persistent daily nonvertiginous dizziness that is aggravated by complex visual environments, visual motion, patterns, and using a computer or smartphone; these symptoms may warrant a separate diagnosis of persistent postural perceptual dizziness.

Readings

Eggers SDZ. Episodic spontaneous dizziness. Continuum (Minneap Minn) 2021;27(2, Neuro-otology).

Disclosures

For this program, the following was disclosed: Dr Eggers has received research/grant support from the National Institutes of Health/National Institute on Deafness and Other Communication Disorders (U01 DC13256), publishing royalties from UpToDate, Inc, and technology intellectual property royalty payments from the Mayo Clinic.

Unlabeled Use of Products/Investigational Use Disclosure: Dr Eggers discusses the unlabeled/investigational use of amitriptyline, atenolol, betahistine, cinnarizine, cyproheptadine, diazepam, diltiazem, dimenhydrinate, flunarizine, gabapentin, lamotrigine, lomerizine, lorazepam, metoclopramide, metoprolol, nortriptyline, pizotifen, venlafaxine, and verapamil, which are not approved by the US Food and Drug Administration (FDA) for the treatment of vestibular migraine; carbamazepine, lacosamide, and oxcarbazepine, which are not FDA approved for the treatment of vestibular paroxysmia; and rizatriptan, which is not FDA approved for the treatment of motion sickness.

To view disclosures of planning committee members with relevant financial relationships, visit: legacy.audio-digest.org/continuumaudio/committee. All other members of the planning committee report nothing to disclose.

The material presented in Continuum Audio has been made available by the AAN for educational purposes only and is not intended to represent the only method or procedure for the medical situations discussed but rather to present an approach, view, statement, or opinion of the speaker(s), which may be helpful to others who face similar situations. Opinions expressed by the speakers are not necessarily those of the AAN, its affiliates, or the publisher. The AAN, its affiliates, and the publisher disclaim any liability to any party for the accuracy, completeness, efficacy, or availability of the material contained in this program (including drug dosages) or for any damages arising out of the use or nonuse of any of the material contained in this program.

Acknowledgements

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