Ocular and Cervical Vestibular Evoked Myogenic Potentials in Patients With Vestibular Migraine

The patterns of anti-compensatory saccades of the SHIMP paradigm can differentiate vestibular migraine from healthy individuals

PURPOSE

The aim of the present study was to characterize the HIMP and SHIMP test findings in individuals with vestibular migraine.

METHOD

The study comprised two groups- group I consisted of twenty five adults diagnosed with Vestibular migraine, and group II comprised twenty-five age matched healthy individuals. HIMP & SHIMP were administered using the ICS impulse system for both groups.

RESULTS

Mann-Whitney U test revealed a significant difference (p< 0.05) in VOR gain and VOR suppression gain between the vestibular migraine and healthy individuals. All the subjects in the vestibular migraine group manifested either of the four patterns of anti-compensatory saccades (ACS): (a) bilaterally absent ACS, (b) bilaterally scattered ACS or (c) typical ACS on one side with scattered ACS on the other side (d) unilaterally absent ACS. On the other hand, all the healthy individuals exhibited the presence of an organised ACS bilaterally.

CONCLUSION

VOR pathway is affected in individuals with vestibular migraine. Also, various patterns of ACS are more effective in identifying the subtle vestibular lesion in vestibular migraine. These patterns are useful in differentiating vestibular migraine from healthy individuals.

Accuracy of Repetitive Ocular Vestibular-Evoked Myogenic Potentials to Diagnose Myasthenia Gravis in Patients With Ptosis or Diplopia

BACKGROUND AND OBJECTIVES

We developed repetitive ocular vestibular-evoked myogenic potentials (roVEMP) as an electrophysiologic test that allows us to elicit the characteristic decrement of extraocular muscles in patients with ocular myasthenia gravis (OMG). Case-control studies demonstrated that roVEMP reliably differentiates patients with OMG from healthy controls. We now aimed to evaluate the diagnostic accuracy of roVEMP for OMG diagnosis in patients with ptosis and/or diplopia.

METHODS

In this blinded prospective diagnostic accuracy trial, we compared roVEMP in 89 consecutive patients presenting with ptosis and/or diplopia suspicious of OMG with a multimodal diagnostic approach, including clinical examination, antibodies, edrophonium testing, repetitive nerve stimulation of accessory and facial nerves, and single-fiber EMG (SFEMG). We calculated the roVEMP decrement as the ratio between the mean of the first 2 responses compared with the mean of the sixth-ninth responses in the train and used cutoff of >9% (unilateral decrement) in a 30 Hz stimulation paradigm.

RESULTS

Following a complete diagnostic work-up, 39 patients (44%) were diagnosed with ocular MG, while 50 patients (56%) had various other neuro-ophthalmologic conditions, but not MG (non-MG). roVEMP yielded 88.2% sensitivity, 30.2% specificity, 50% positive predictive value (PPV), and 76.5% negative predictive value (NPV). For comparison, SFEMG resulted in 75% sensitivity, 56% specificity, 55.1% PPV, and 75.7% NPV. All other diagnostic tests (except for the ice pack test) also yielded significantly higher positive results in patients with MG compared with non-MG.

DISCUSSION

The study revealed a high sensitivity of 88.2% for roVEMP in OMG, but specificity and PPV were too low to allow for the OMG diagnosis as a single test. Thus, differentiating ocular MG from other neuro-ophthalmologic conditions remains challenging, and the highest diagnostic accuracy is still obtained by a multimodal approach. In this study, roVEMP can complement the diagnostic armamentarium for the diagnosis of MG.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that in patients with diplopia and ptosis, roVEMP alone does not accurately distinguish MG from non-MG disorders.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov: NCT03049956.

Recent Developments in Vestibular Migraine: A Narrative Review

PURPOSE

The aim of this study was to review current literature regarding the epidemiology of vestibular migraine (VM), patient presentation, pathogenesis, and treatment.

RECENT FINDINGS

VM is becoming an increasingly recognized condition in the United States, currently affecting 2.7% of people. Patients may experience vestibular symptoms, such as vertigo and imbalance, with or without other migrainous symptoms. Recent evidence has also shown that patients with VM are at higher risk for cochlear dysfunction, such as sudden deafness, sensorineural hearing loss, and tinnitus. The heritability and genetics are not well understood, and the pathogenesis may involve calcitonin gene-related peptide, which is also implicated in migraine headaches. A disease-specific patient reported outcome measure, the Vestibular Migraine Patient Assessment Tool and Handicap Inventory, was recently developed and validated. A limited number of controlled trials have assessed various therapies for VM, including triptans and beta-blockers. More data are needed to understand whether or not currently available migraine treatments are effective for VM.

SUMMARY

VM is a common etiology of vertigo and dizziness, presenting with a characteristic spectrum of symptoms. Early data suggest that migraine treatments may be helpful in some cases.

Augmented ocular vestibular-evoked myogenic potentials in postural orthostatic tachycardia syndrome

PURPOSE

To delineate the association between otolith function and changes in mean orthostatic blood pressure (BP) and heart rate (HR) in patients with postural orthostatic tachycardia syndrome (POTS).

METHODS

Forty-nine patients with POTS were prospectively recruited. We analyzed the results of ocular vestibular-evoked myogenic potentials (oVEMPs) and cervical vestibular-evoked myogenic potentials (cVEMPs), as well as head-up tilt table tests using a Finometer. The oVEMP and cVEMP responses were obtained using tapping stimuli and 110 dB tone-burst sounds, respectively. We measured maximal changes in 5-s averaged systolic BP (SBP), diastolic BP (DBP), and heart rate (HR) within 15 s and during 10 min after tilting. We compared the results with those of 20 age- and sex-matched healthy participants.

RESULTS

The n1-p1 amplitude of oVEMPs was larger in patients with POTS than in healthy participants (p = 0.001), whereas the n1 latency (p = 0.280) and interaural difference (p = 0.199) did not differ between the two. The n1-p1 amplitude was a positive predictor for POTS (odds ratio 1.07, 95% confidence interval 1.01-1.13, p = 0.025). Body weight (p = 0.007) and n1-p1 amplitude of oVEMP (p = 0.019) were positive predictors for ΔSBP15s in POTS, whereas aging was a negative predictor (p = 0.005). These findings were not observed in healthy participants.

CONCLUSIONS

Augmented utricular inputs may be associated with a relative predominance of sympathetic over vagal control of BP and HR, especially for an early response during orthostasis in patients with POTS. Overt sympathoexcitation due to exaggerated utricular input and lack of readaptation may be associated with the pathomechanism of POTS.

Asymmetric Ocular Vestibular Evoked Myogenic Potentials in Pediatric Vestibular Migraine

OBJECTIVE

Although ocular vestibular evoked myogenic potentials (oVEMP) abnormalities have been associated with vestibular migraine (VM) in adults, no studies have evaluated this in pediatric patients with VM. oVEMP asymmetry with normal cervical VEMP (cVEMP) findings may be a reliable VM biomarker in adults. We characterize VEMP results among pediatric patients with VM and benign recurrent vertigo of childhood (BRVC), a migraine precursor, and compare these results with VEMP findings from pediatric patients with nonmigrainous vestibular diagnoses.

METHODS

Four hundred seventy-four pediatric patients were evaluated over a 3-year period in a multidisciplinary pediatric vestibular clinic, 139 of whom met the inclusion criteria. Records were reviewed for history, audiometry, and vestibular testing results. VEMP testing was performed with a 500-Hz tone burst. Based on adult normative data, oVEMP asymmetry was defined as greater than 33% interaural difference; cVEMP asymmetry was defined as greater than 41%.

RESULTS

Eighty subjects had VM or BRVC (mean [standard deviation] 12.8 [3.8] yr; range, 4.3-18.2 yr). Fifty-nine subjects received vestibular diagnoses other than VM or BRVC (nonmigrainous group; mean [standard deviation] age, 13.0 [3.6] yr; range, 5.14-18.9 yr). A greater proportion of the VM/BRVC group demonstrated oVEMP asymmetry with normal cVEMP as compared with the nonmigrainous group (22.5% versus 10.1%; p < 0.05). Zero subjects in the VM/BRVC group demonstrated cVEMP asymmetry versus three subjects (4.9%) of the nonmigrainous group.

CONCLUSIONS

VM and BRVC are notable causes of migraine-related vertigo among pediatric patients. Of VM/BRVC patients, 22.5% had oVEMP asymmetry with normal cVEMP. Similar to the adult VM population, this finding may be a useful biomarker in the right clinical setting for pediatric VM.

LEVEL OF EVIDENCE

4.

Interventional Study of Flunarizine Therapy on Symptom Relief and Vestibular Evoked Myogenic Potential Changes in Individuals with Vestibular Migraine

INTRODUCTION

Migraine is the third most common disease in the world with an estimated prevalence of 14.7%. The purpose of this study was to identify the characteristic changes in cervical and ocular vestibular evoked myogenic potential (VEMP) and analyse changes in symptoms and VEMP after flunarizine therapy in patients diagnosed with vestibular migraine (VM).

METHODS

Prospective interventional study was conducted on 31 VM patients. Cervical VEMP (cVEMP) and ocular VEMP (oVEMP) were recorded. Flunarizine (10 mg) was given once daily for two consecutive months. Prophylactic therapy was monitored with a monthly follow-up assessment of their symptoms and VEMP was repeated after 2 months.

RESULTS

Headache was the chief complaint (67.7%). Vertigo was spontaneous and mostly moderate in intensity (93%). cVEMP was absent in 1 patient and oVEMP was absent in 3 patients. Post prophylactic treatment with flunarizine, there was significant reduction in the frequency (p = 0.001) and duration (p = 0.001) of headache and frequency (p = 0.001), duration (p = 0.001), and intensity (p = 0.009) of vertigo. cVEMP and oVEMP showed no significant differences (p > 0.05) between pre- and post-treatment recordings.

CONCLUSION

Treatment with flunarizine helps in considerably reducing the episodes and duration of headache, as well as episodes, duration, and intensity of vertigo.

Video Head Impulse Test Demonstrates a Residual Function after Plugging of Dehiscent Superior Semicircular Canal

OBJECTIVE

Plugging a symptomatic dehiscent superior semicircular canal (SSCC) often leads to a nonfunctional postoperative canal. However, in some instances, a residual function has been described. This study attempts to describe what factors may lead to such residual function.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

Thirty-five patients with confirmed SSCC dehiscence.

INTERVENTION

Video head impulse test was conducted pre- and postoperatively to assess any difference in the function of the SSCC.

MAIN OUTCOME MEASURES

Mean gain and pathological saccades were recorded according to well-established thresholds along with dehiscence length and location to evaluate any associations to residual canal function.

RESULTS

When comparing preoperative to postoperative SSCC abnormal gains, a significant increase was observed after plugging ( p = 0.023). This also held true when abnormal gain and pathologic saccades were taken together ( p < 0.001). Interestingly, 55.3% of patients were observed to remain with a residual SSCC function 4 months postoperatively even with a clinical improvement. Of these, 47.6% had normal gain with pathologic saccades, 38.1% had an abnormal gain without pathologic saccades, and 14.3% had normal gain without pathologic saccades (normal function). Preoperatively, SSCC abnormal gain was associated with a larger dehiscence length mean ( p = 0.002). Anterosuperior located dehiscences were also associated with a larger dehiscence length mean ( p = 0.037). A residual SSCC function after plugging was associated with a shorter dehiscence length regardless of location ( p = 0.058).

CONCLUSION

Dehiscence length and location may be useful in predicting disease symptomatology preoperatively and canals function recovery after plugging. These factors could be used as indicators for preoperative counseling and long-term management.

Vestibular Migraine

PURPOSE OF REVIEW

To explore recent developments in vestibular migraine (VM).

RECENT FINDINGS

This review discusses the current diagnostic criteria for VM in the adult and pediatric populations, as proposed by the International Headache Society and Bárány Society. Recent VM studies confirm the prior findings and reveal new insights, including the wide range of vestibular symptoms, symptoms in the attack-free period, and triggers. Many patients experience persistent vestibular symptoms, even in the absence of acute attacks, which often significantly impact patients' quality of life. The syndrome of benign recurrent vertigo and its relationship to migraine, VM, and Meniere's disease is also discussed. There is a dearth of randomized controlled trials in VM treatment. Prospective and retrospective studies support the benefit of many migraine treatments are effective in VM, including neuromodulation, and calcitonin gene-related peptide monoclonal antibodies. VM affects almost 3% of the population, but remains under-diagnosed. Recent diagnostic criteria can help clinicians diagnose VM in adults and children.

Exploring Vestibular Assessment in Patients with Headache and Dizziness

Patients often report symptoms of headache and dizziness concomitantly. Symptoms of dizziness can be explored with a comprehensive vestibular assessment, allowing for the investigation of central and peripheral vestibular system contributions to symptoms of dizziness. Patients who report both symptoms of headache and dizziness demonstrate abnormalities of the vestibular system which can be measured quantitatively. Completion of comprehensive vestibular testing can help to guide diagnosis and strategies for intervention.

Evolution of migraine vertigo in overlapping syndrome with Ménière's disease: prognostic role of instrumental examination

Introduction

Migraine vertigo (MV) and Ménière’s disease (MD) share several signs and symptoms such as tinnitus, fullness, photophobia, phonophobia, headache and vertigo spells lasting hours.

Objective

The aim of the present study was to prospectively observe patients with MV with a sporadic audiological symptom evaluated with clinical examination, Vestibular Evoked Myogenic Potentials (VEMPs), ECochG and v-HIT.

Results

The finding of VEMP asymmetry, according to our cut-off of 33% of difference between sides, resulted in 20 cases, of which 6 had asymmetry of both c-VEMPs and o-VEMPS, all with development of fluctuating hearing during follow-up. ECochG was positive for endolymphatic hydrops in 12 patients.

Conclusions

The evolution of MV may have a variable course in which some patients may develop symptoms typical of MD. The two diseases may be contextually present at the same time configuring an overlapping syndrome, and asymmetric VEMPs might predict development of fluctuating hearing.

Vestibular Migraine and Its Comorbidities

Vestibular migraine (VM) is one of the most common neurologic causes of vertigo. Symptoms and International Classification of Headache Disorders criteria are used to diagnose VM because no objective tests, imaging or audiologic, have been shown to reliably diagnose this condition. Central auditory, peripheral, and central vestibular pathway involvement has been associated with VM. Although the interaction between migraine and other vestibular disorders can be a challenging scenario for diagnosis and treatment, there are data to show that vestibular rehabilitation and a variety of pharmacologic agents improve reported symptoms and vertigo frequency.

Do we need to reconsider the classification of vestibular migraine?

Introduction: Vestibular migraine (VM) is a complex disease characterized by recurrent episodes of migraine associated with vertigo attacks that are observed in 1-3% of the general population. Given its high prevalence and the impact on the health system, it is important to characterize these patients, in order to offer an accurate diagnosis and a proper treatment. As the diagnosis of VM is based on clinical features, the study of potential biomarkers has gained more interest in the last years, to improve the precision in the diagnosis of this disease. The aim of this review is to summarize the main tests available for the diagnosis of VM, including the accuracy of biomarkers for the diagnosis of VM.Areas covered: This review summarizes the main information on VM, including all diagnosis records published in the field in the last 10 years, and focusing on candidate biomarkers for the diagnosis of VM patients.Expert opinion: There is a limited knowledge in the pathophysiology of VM. The search of biomarkers for diagnosis of VM is needed to improve the precision in the diagnosis promoting clinical and translational research. The potential reclassification of VM will depend upon the discovery and validation of these biomarkers.

Recurrent vestibulopathy: are cVEMP, oVEMP and inner ear MRI useful to distinguish patients with Menière's disease and vestibular migraine?

PURPOSE

The aim of this study was to assess the rate of endolymphatic hydrops (EH) on MRI and the rate of otolithic dysfunction with cVEMP and oVEMP, in patients with recurrent vertigo such as Menière's disease (MD), vestibular migraine (VM) and vestibular Menière's disease (vMD).

METHODS

In this retrospective study, we performed 3D-FLAIR sequences with delayed acquisition in 20 MD, 20 VM and 20 vMD patients. Each subject was then assessed for the presence of EH on MRI. All patients underwent pure-tone audiometry, cVEMP and oVEMP.

RESULTS

In MD patients, EH was observed in 18 (90%) out of 20 patients while EH was observed in only 1 MV (5%) and 1 vMD (5%) patients. We found significant differences between groups for the presence of EH on MRI (p = 0.001). MD patients had significant higher PTA level (p < 0.001) and oVEMP impairment than MV and vMD (p = 0.08 and p = 0.06, respectively). However, no significant differences were observed for cVEMP impairment, either asymmetric ratio (p = 0.36) and 1000/500 ratio (p = 0.20).

CONCLUSIONS

Concerning cVEMP, we observed no significant differences between VM, vMD and MD. However, we observed higher oVEMP impairment, PTA level and EH on MRI in MD patients. We believe that MRI could be used to differentiate MD from VM patients with cochlear symptoms. However, in cases of migraine associated with recurrent vertigo and without cochlear symptoms, we believe that MRI is not a useful tool to differentiate between VM and vMD.

Effects of Tonic Muscle Activation on Amplitude-Modulated Cervical Vestibular Evoked Myogenic Potentials (AMcVEMPs) in Young Females: Preliminary Findings

Cervical vestibular evoked myogenic potentials (cVEMPs) are usually elicited by transient tonebursts, but when elicited by amplitude-modulated (AM) tones, they can provide new information about cVEMPs. Previous reports of cVEMPs elicited by AM tones, or AMcVEMPs, have not systematically examined the effects of tonic EMG activation on their response properties. Fourteen young, healthy female adults (ages 20-24) with clinically normal audiograms participated in this study. AMcVEMPs were elicited with bone-conducted 500 Hz tones amplitude modulated at a rate of 37 Hz and recorded for five different EMG targets ranging from 0 to 90 μV. Amplitude increased linearly as tonic EMG activation increased. Signal-to-noise ratio (SNR) was minimal at 0 μV, but robust and with equivalent values from 30 to 90 μV; phase coherence and EMG-corrected amplitude had findings similar to SNR across EMG target levels. Interaural asymmetry ratios for SNR and phase coherence were substantially lower than those for raw or corrected amplitude. AMcVEMP amplitude scaled with tonic EMG activation similar to transient cVEMPs. Signal-to-noise ratio, phase coherence, and EMG-corrected amplitude plateaued across a range of EMG values, suggesting that these properties of the response reach their maximum values at relatively low levels of EMG activation and that higher levels of EMG activation are not necessary to record robust AMcVEMPs.

Vestibular evoked myogenic potentials in vestibular migraine and Menière's disease: cVEMPs make the difference

OBJECTIVE

Vestibular evoked myogenic potentials (VEMPs) have been suggested as biomarkers in the differential diagnosis of Menière's disease (MD) and vestibular migraine (VM). The aim of this study was to compare the degree of asymmetry for ocular (o) and cervical (c) VEMPs in large cohorts of patients with MD and VM and to follow up the responses.

STUDY DESIGN

Retrospective study in an interdisciplinary tertiary center for vertigo and balance disorders.

METHODS

cVEMPs to air-conducted sound and oVEMPs to bone-conducted vibration were recorded in 100 patients with VM and unilateral MD, respectively. Outcome parameters were asymmetry ratios (ARs) of oVEMP n10p15 and cVEMP p13n23 amplitudes, and of the respective latencies (mean ± SD).

RESULTS

The AR of cVEMP p13n23 amplitudes was significantly higher for MD (0.43 ± 0.34) than for VM (0.26 ± 0.24; adjusted p = 0.0002). MD-but not VM-patients displayed a higher AR for cVEMP than for oVEMP amplitudes (MD 0.43 ± 0.34 versus 0.23 ± 0.22, p < 0.0001; VM 0.26 ± 0.14 versus 0.19 ± 0.15, p = 0.11). Monitoring of VEMPs in single patients indicated stable or fluctuating amplitude ARs in VM, while ARs in MD appeared to increase or remain stable over time. No differences were observed for latency ARs between MD and VM.

CONCLUSIONS

These results are in line with (1) a more common saccular than utricular dysfunction in MD and (2) a more permanent loss of otolith function in MD versus VM. The different patterns of o- and cVEMP responses, in particular their longitudinal assessment, might add to the differential diagnosis between MD and VM.

Vestibular Lab Testing: Interpreting the Results in the Headache Patient with Dizziness

PURPOSE OF REVIEW

To provide an overview of vestibular lab testing and to familiarize the reader with common results observed in headache patients with dizziness.

RECENT FINDINGS

The latest research indicates variable levels of both peripheral and central vestibular dysfunction in headache populations with dizziness. Mechanisms may include vestibulocerebellar loss of inhibition, central vestibular network misfiring, and peripheral pathology aggravating central hypersensitization. Headache patients are commonly affected by dizziness stemming from various etiologies. Although history is still the gold standard in diagnosis, vestibular lab testing can identify the integrity of vestibular function. Research is emerging and future directions are encouraging.

Short Communication: The Belly-Tendon Derivation Yields Superior Ocular Vestibular Evoked Myogenic Potential Amplitudes in a Normal Pediatric Sample

Purpose The purpose of the investigation was to determine whether the "belly-tendon" electrode derivation produced ocular vestibular evoked myogenic potentials (oVEMPs) in children that were superior to those recorded with the infraorbital-chin electrode derivation. Method This was a prospective observational study using a sample of convenience at a tertiary care medical center. Subjects were 13 children between the ages of 5 and 12 years. We compared the latency of the N1 wave and the N1-P1 peak-to-peak amplitude for the belly-tendon electrode derivation to the infraorbital-chin electrode derivation. Results The belly-tendon electrode derivation was associated with superior N1-P1 amplitudes compared to the infraorbital-chin electrode derivation. However, the large amplitude was also associated with greater variability compared to the infraorbital-chin derivation. There were no significant electrode derivation-based differences in N1 latency. Additionally, there was no predictable relationship between age and oVEMP amplitude. Conclusion As shown previously in adults, the belly-tendon electrode derivation produces significantly larger oVEMP amplitudes compared to the infraorbital-chin electrode derivation.

Vestibular evoked myogenic potential (VEMP) results in migraine and migrainous vertigo

Background: The pathophysiology of vertigo is not fully known; thus, it is difficult to diagnose vestibular migraine (VM) in some migraine patients with vertigo symptoms.Aims/objectives: We aimed to evaluate the diagnostic value of cervical vestibular evoked myogenic potential (cVEMP) in patients with VM.Materials and Methods: Thirty-two patients diagnosed with migraine and 31 patients with VM were prospectively included in this study. The cVEMP responses were obtained, and P1-N1 latency, interpeak amplitude, amplitude asymmetry ratio were calculated. The patients' demographics, results of physical and audiometric examinations, and VEMP records as well as absence of responses were evaluated and compared between groups.Results: The incidence of ears with absence VEMP responses was found to be numerically higher in the migraine group than in the VM group (p = .106). Additionally, there were no statistically significant differences detected between the groups in terms of the p13 or n23 latency, interpeak amplitude, and amplitude asymmetry ratio measured in both right and left ears (p > .05).Conclusions: The increased rate of absent VEMPs was associated with the hypoperfusion of the sacculo-collic reflex pathway in migraine patients. In addition, it was concluded that VEMP reflex responses appear to be insufficient to differentiate between VM and migraine diagnoses.

Vestibular evoked myogenic potentials (VEMP) captured in the forearm flexor muscles: a study of its feasibility and reference ranges

OBJECTIVE

To determine the central tendency measures and variability of vestibular evoked myogenic potential (VEMP) with regard to the latency and wave amplitude when potentials are captured from the flexor muscles of the forearm.

METHODS

Ten adult volunteers with normal hearing underwent examination of their forearm flexor muscles (right and left sides; 20 samples in total) for VEMP acquisition. To this end, 200 tone burst stimuli at a 500 Hz frequency and 95 dBnHL intensity were promediated.

RESULTS

No statistical differences were observed in VEMP responses acquired from the right and left forearm flexor muscles concerning P34 and N44 latencies (p=0.32 and 0.90, respectively). The mean latency obtained for the P34 wave component was 34.9 ms (±2.6), with a lower limit equal to 29.3 and an upper limit equal to 40.4 ms. The average latency of the N44 wave component was 43.6 ms (±2.1), with a lower limit of 39.1 ms and an upper limit of 48.1 ms. The results were consistent and had low variability, and showed an average asymmetry index of 15.4 (±10.7). These findings indicate that potentials may be investigated in different age groups and in specific clinical populations, such as pathologies that may alter the neuronal transmission of the inferior vestibular pathway, especially when a longer portion is observed.

CONCLUSIONS

VEMP recording from forearm flexors is both feasible and stable, with latency reference ranges between 29.3 and 40.4 ms for P34, and 39.1 and 48.1 ms for N44.

Vestibular Migraine

The term vestibular migraine designates recurrent vertigo that is caused by migraine. Vestibular migraine presents with episodes of spontaneous or positional vertigo lasting seconds to days that are accompanied by migraine symptoms. Because headache is often absent during acute attacks, other migraine features have to be identified by thorough history taking. In contrast, vestibular testing serves mainly for the exclusion of other diagnoses. Treatment still lacks solid evidence. It is targeted at the underlying migraine and comprises explanation and reassurance, lifestyle modifications, and drugs.

Vestibular migraine: An update on current understanding and future directions

BACKGROUND

Vestibular migraine is among the most common causes of recurrent vertigo in the general population. Despite its prevalence and high impact on healthcare cost and utilization, it has remained an under-recognized condition with largely unknown pathophysiology. In the present article, we aim to provide an overview of the current understanding of vestibular migraine.

METHODS

We undertook a narrative literature review on the epidemiology, presentations, clinical and laboratory findings, pathophysiology, and treatments of vestibular migraine.

RESULTS

Currently, the diagnosis of vestibular migraine relies solely on clinical symptoms since clinical tests of vestibular function are typically normal, or difficult to interpret based on inconsistent results reported in earlier studies. The challenges related to diagnosis of vestibular migraine lie in its relatively broad spectrum of manifestations, the absence of typical migraine headaches with vestibular symptoms, and its very recent definition as a distinct entity. Here, we highlight these challenges, discuss common vestibular symptoms and clinical presentations in vestibular migraine, and review the current aspects of its clinical diagnosis and evaluation. The concepts related to the pathophysiology and treatment of vestibular migraine are also discussed.

CONCLUSION

Vestibular migraine is still underdiagnosed clinically. Future studies are needed to address the pathophysiological mechanisms and investigate effective treatment regimens.