VESTIBULAR MIGRAINE AND VERTIGO

Correlation Between cVEMP and ABR for the evaluation of

Vestibular Migraine

Mehmet Sürmeli, Reyhan Sürmeli, İldem Deveci, Serap Önder, Ayşe Destina Yalçın, Çağatay Oysu

ABSTRACT

OBJECTIVE: Vestibular migraine is a clinical condition characterized by temporal overlap between vestibular symptoms and migraine. In this study, we aimed to determine the possible changes in vestibular myogenic potential (cVEMPs) and auditory brainstem response (ABR) in patients with vestibular migraine and migraine.

MATERIALS and METHODS: A total of 86 participant who have no hearing loss or additional disease between the age of 18-45 enrolled into three different groups: group 1 vestibular migraine, group 2 migraine without aura, and group 3 healthy controls. cVEMP and ABR were performed to all participants that in attack and attack free period. Differences between right and left sides were calculated.

RESULTS: There was no significant difference concerning the p13-n23 latencies among the all groups. There were statistical significant differences related to cVEMP p13-n23 amplitudes among the group 1-2-3. This significant differences were belonging to group 1 when compared with other groups (p<0.05). When we compared the cVEMP, p13-n23 amplitude values of the cases with vestibular migraine during attacks and attack free periods, a statistically significant decrease were determined in attack period (p<0.01). Additionaly, when we compared group 1 and group 3, wave V peak latencies in ABR were prolonged significantly in group 1 (p<0,05)

CONCLUSIONS: cVEMP and ABR can be used as diagnostic criteria on patients with vestibular migraine during the attack. Further studies with larger groups needed to verify our findings.

KEYWORDS: Vestibular migraine, vestibular evoked myogenic potential, auditory brainstem response

INTRODUCTION

Currently understood the cervical vestibular evoked myogenic potential (cVEMP) was first described by Colebatch et al [1] and Colebatch and Halmagyi [2] . The cVEMPs is a non-invasive and relatively quick test providing information about the function and integrity of the ipsilateral saccule and ipsilateral inferior vestibular nerve. cVEMP is an inhibitory myogenic response that can be measured at the tonically contracted sternocleidomastoid muscle (SCM) in response to acoustic stimuli 1. Findings of recent studies emphasizes potential role of cVEMP in the diagnosis of several peripheral vestibular disorders including Meniere's disease, benign paroxysmal positional vertigo, vestibular neuritis, idiopathic vestibulopathy, acoustic neuromas and dehiscence of the superior semicircular canal [3-8].

Brainstem auditory evoked response (ABR), consist of a sequence of volume-conducted waves recorded at the scalp following a click stimulus to the ear. Seven most common waveforms designed between I to VII; wave I probably represent activation of acoustic nerve, wave III represents cochlear nuclei, wave IV represents lateral lemniscus tracts and nuclei and wave V represents inferior colliculi [9]. The decline and prolongation in the latency of wave V may indicate some physiological dysfunction in the auditory system up to the brainstem level.

Migraine has long been described as a clinical condition related with various vestibular syndromes [10-13]. In recent years many studies were published subjecting the cVEMP responses in migraine and although there were studies stating normal cVEMP responses and decreased amplitudes [14-17], some studies found out delayed or lack of cVEMP responses [18-21]. Vestibular migraine is known as migrainous vertigo/dizziness, migraine-related vestibulopathy, and migraine-associated dizziness or vertigo. This is a disabling neurological disorder characterized by vestibular symptoms, such as vertigo, dizziness, or imbalance. It should be noted that the headache does not necessarily have to occur at the same time as the vertigo symptoms. When the literature is examined it is observed that the studies which examine the relationship between migraine and cVEMP present whereas no study which examines the relationship between vestibular migraine, cVEMP and ABR presents.

The purpose of this study to determine characteristics of cVEMPs and ABR responses of the patients with vestibular migraine and migraine in contrast to healthy controls. In this study the cVEMP and ABR changes during the attack period of the vestibular migraine were compared with cVEMP and ABR values of the participant with migraine and healthy control group. In addition the cVEMP and ABR findings of the patient with vestibular migraine were compared with the values in attack free period. To our knowledge, this is the first clinical study to compare the cVEMP and ABR changing in Vestibular Migraine and Migraine.

MATERIALS and METHODS

This study was conducted both in Neurology and Otorhinolaryngology Departments. Informed consent obtained from the patients.

All participants of study were between age of 18 to 45. None of the participant of study had auditory symptoms and any other chronic disease history. The pure tone audiometric examination and MRI scanning was performed for each participant in order confirm that participant have hearing loss and other diseses. The cases with hearing loss and additional disease were excluded from the study. ABR and cVEMP were performed on all participants. All tests were performed on headache and/or vertigo-free days and during vertigo attacks.

All participants of study were divided into three groups. In group 1, thirty-two patients with definite VM (28 female and 4 male, mean age 33.2±10.2) defined by International Headache Society (2013) were included in the study (Table 1). Patients with VM suffer attacks of vertigo that often occur in isolation from headache attacks mostly spontaneous or positional vertigo lasting seconds to days. Motion intolerance during attacks was the most common complaint (25 patients, 78% of the group). Six patients had vertigo attacks after the headaches, 11 patient's vertigo attacks preceded the headaches, and 15 patients had simultaneous headache and vertigo. None of the patients had auditory symptoms accompanying vertiginous symptoms. 24 patients’ headache was hemicranial and 8 patients’ headache was holocranial. Neurological examination findings of the patients were normal. In group 2, twenty-seven patients with migraine without aura (22 female and 5 male, mean age 31.2±9 years) fulfilling the criteria of the International Classification of the Headache Disorders, 3rd ed. (ICHD-II 2013) (Headache classification subcommittee, 2013) were included in the study. Severe pulsatile headache attacks were usually hemicranial in 20 patients and at the vertex in 7 patients. All of the patients had nausea and/or vomiting complaints. Patients with vestibular history or existing symptoms and hearing loss were excluded from the study. In group 3 (control), twenty seven healthy volunteers of comparable age and gender distribution (20 female, 7 male, mean age 33.4±9.8 years) did not have any vestibular symptoms and migraine. Audiometric tests were normal in all of the groups. Patients with hearing loss were excluded from the study.

ABR of the patients were recorded by using a Vivosonic device (Vivosonic; Vivosonic Inc, Toronto ON M9C 5K5 Canada). The ABR was elicited with an alternating rarefaction and condensation click stimulus delivered via an unshielded headphone (Vivosonic; Vivosonic Inc, Toronto ON M9C 5K5 Canada), with 0.1 ms clicks at a rate of 37.7 click/s. Each trial was performed at an intensity of 70 dB nHL. White-noise masking (40 dB nHL) was performed in the contralateral ear. Before performing the ABR test, all the patients were proceeded to pre-cleaning of the skin and attachment of the disposable electrodes in frontopolar region (Fpz), right and left mastoids (M1 and M2) in accordance with norms by the International Electrode System (IES 10-20). Electrode impedance was <5 kΩ. The filter bandwidth used for recording was 100-3000 Hz. Totals of 1000 to 2000 responses were averaged. Each test was carried out 2 or 3 times to ensure that the results were reproducible. Results were recorded both ipsilateral and contralateral to stimulation.

The cVEMPs were recorded by using a Vivosonic device (Vivosonic; Vivosonic Inc, Toronto ON M9C 5K5 Canada). Active electrode was placed to the center point of the same sided sternocleidomastoid (SCM) muscle ; reference electrode was placed on upper 2/3 portion of the SCM and ground electrode was placed in the middle of the forehead to record superficial EMG activity. Patients were placed in the supine position in a sound isolated room, and when the stimulus was given, they responded by straightening and turned to contralateral side of the stimulus, that provided the contraction of the SCM muscle. Contraction of SCM muscle was monitored with manometer [22]. Stimulus was given in an order of right and left ears, and sternocleidomastoid muscle electromyographic activity was recorded from the ipsilateral direction. Electrode impedance was <5 kΩ. The acoustic stimuli were clicks at an intensity of 100 dBnHL ( normal hearing level) of 0.1 ms duration, delivered at a frequency of 5 Hz through a headphone unilaterally to each ear. The EMG signal was bandpass filtered from 10 to 1000 Hz and averaged during a 100 ms interval. Totals of 200 responses were averaged. P13 and n23 were the peak waves with positive/negative polarity concerning their latencies. The latencies of peaks p13, p23 and peak-to-peak amplitude of p13-n23 were evaluated. To accomplish independence from the level of background activation, the amplitude of the cVEMPs was expressed as the ratio of peak to peak amplitude separated by a mean pre-stimulus rectified EMG measured during the recording [23].

The SPSS Version 20 program (IBM Corporation; Armonk, NY, USA) was used in statistical analysis. Besides standard descriptive statistical calculations (mean, median and standard deviation), qualitative parameters showing normal distribution were compared with İndependent samples t-test and parameters showing abnormal distribution were compared with Mann Whitney U test. One-way ANOVA test was used to compare the quantitative data between ≥3 group showing normal distribution and Tamhane and Tukey HDS test was used for the determination of the group responsible for the difference. Kruskal Wallis test was used to compare the data between ≥3 group comparisons of quantitative parameters showing abnormal distribution. Paired Samples Test and Wilcoxon Signed Ranks Test were used to evaluate parameters in the groups. Fisher-Freeman-Halton Test was used to evaluate qualitative data comparisons. The statistical significance level was established at p<0,01 and p<0.05. Power analysis was conducted to determine the necessary patient population for obtaining reliable latencies and amplitudes of cVEMP and ABR values.

RESULTS

The cVEMPs latency and p13-n23 amplitudes of the patients with vestibular migraine, migraine without aura and healthy control groups (group1-group 2-group 3) were obtained (Table 2). In the control group (group 3), the average latency of p13 on the right side was 15:53ms (min:14 ms, max: 17 ms) and on the left side was 15.26 ms (min: 14 ms max: 17 ms). Also, in the control group the average latency of n23 on the right side was 23.43 ms (min: 15 ms, max: 25 ms) and on the left side was 23.25 ms (min: 14 ms max: 26 ms). There was no significant difference among the groups in terms of right and left p13 latencies (p=0,541; p=0,256; p>0,05). Additionally differences for the right and left n23 latencies were not statistically significant (p=0,606; p=0,189; p>0,05).

Group 1 (VM), cVEMP p13-n23 average amplitudes in attack period was 1.65 µv (SD:1.26) on the right side and 1.62 µv (SD:1.29) on the left side. Additionaly, group 2 (migraine) cVEMP p13-n23 average amplitudes were 2.41 µv (SD:1.25) on the right side and 2.42 µv (SD:1.02) on left side. In the group 3 (healty controls), p13-n23 average amplitudes was 2.32 µv (SD: 0.56) on the right side, 2.26 µv (SD: 0.55) on the left side. When we compared p13-n23, cVEMP average amplitudes, we found that there were statistically significant differences between of all groups. cVEMP p13-n23 amplitude in the group 1 (VM) was significantly lower than other groups (right side p<0.05, left side p<0.05). There was no significant difference between group 2 and group 3 (right side p>0,05, left side p>0,05,) (Figure 1, Figure 2).

In group 1 (VM), cVEMP evaluation bilateral non-response in 6 patients, left side non-response in 3 patients and right side non-response in 3 patients were recorded. cVEMP responses were normal ranges in all patients during attack free period. When the cVEMP p13-n23 amplitudes of group 1 patients were compared to each other according to attack period and attack free period results, there were statistically significant differences between two periods (p<0.01 and p<0.01). (Figure 3)

In group 1, average peak latency value of wave V in ABR was 5,27 ms (SD:0,31) on the right side and 5,33 ms (SD:0,29) on the left side. Additionaly, in group 2 average peak latency value of wave V in ABR was 5,34 ms (SD:0,17) on the right side, 5,29 ms (SD:0,26), In group 3 (healty control), 5.42 ms (SD:0,24) on the right and 5.46 ms (SD:0,28) on the left side (Table 3). There were no statistically significant differences between right and left peak latency differences in all groups of wave V in ABR (right side p>0,05, left side p>0,05). However, the average wave V peak latency was 6.05 (min: 5.5 ms, max: 6.5 ms) on right side and 5.95 ms (min: 5 ms, max: 6.5 ms) on the left side in 12 (37%) patients of group 1 (VM) that the patients with bilateral or unilateral non response cVEMP result. In these patients V. wave peak latency was prolonged significantly in contrast to control group (p<0,05)

DISCUSSION

The cVEMP which is an indication of vestibulo-colic reflex resulted from the activation of inferior branch of vestibular nerve, vestibular nucleus, vestibular tract, accessorial nucleus, accessorial nerve, and the sternocleidomastoid muscle. In clinical practice it is used in different peripheral and central vestibular diseases. Although delay in reflex is the major pathologic sign, decrease in amplitude and absence of the amplitude reflexes were accepted as pathological. [24,25].

Up-to-date there are several studies conducted on this topic. Clinical trials on paroxysmal positional vertigo has shown that most of the patients had normal cVEMPs excluding some rare cases with amplitude attenuation and/or increased latencies [8,26]. There was lack of response at the affected ear of the 55% of patients diagnosed with Meniere’s disease which was correlated with the low-frequency hearing loss [4]. One of the recent study conducted by Egami et al. in patients with Meniere’s disease; the sensitivity and specificity of VEMPs as diagnoses tool were not validated [27]. In acoustic neuroma, 80% of patients had decreased or no amplitude responses in cVEMP [3] In Multiple sclerosis (MS) disease, cVEMP abnormalities were reported. It was defined that the increases in p13 and n23 latencies might be secondary to demyelination of vestibulo-spinal pathway [28-32].

There are many different literature about migraine. Murofushi et al, used acoustic stimuli tone bursts among the patients with migraine associated vertigo and Meniere’s disease, and calculated a decreased slope of 500-1000 Hz cVEMP. Their findings might be resulted due to shared pathophysiology. Additionally, 36% patients with migraine associated vertigo had prolonged p13 latencies that might have brainstem lesions, showing differences in etiology of VM [21].

Baier et al. reported reduced cVEMP amplitudes in patients with vestibular migraine. Three of the 63 patients with vestibular migraine (5%) had no waveform bilaterally, and one patient had no waveform unilaterally (on the right side)[16]. Baier and Dieterich compared the results of cVEMPs on VM with Meniere’s disease patients. There was bilateral decreased amplitude in cVEMP (%68 VM, %69 Meniere’s disease). These results indicated that, both diseases had similar dysfunction in peripheral vestibular structures [33]. Hong et al. also reported absent abnormality in p13 or n23 latencies and a cVEMP asymmetry in patients with migrainous vertigo. There was only bilaterally absent cVEMPs in the patients group recommending a lesion at the sacculocollic pathway [16]. Boldingh et al. indicated unilateral or bilateral absent cVEMPs response in 44% of their patients with VM and in 25% of their patients with migraine as compared to %3 of the healthy controls [17]. Taylor et al. reported that no significant differences cVEMP amplitudes or symmetry between controls and VM. There was not a caloric test abnormality in these patient groups. Baier et al., 2009; Baier and Dieterich, 2009 reported high range of test abnormalities that were attributed to the narrow normal range used and authors concluded that peripheral vestibular function is usually protected in VM and central mechanisms must be the cause of vertigo [19]. Kandemir et al., reported on patients with migraine without aura, vestibular migraine and tension type headache, it was stated that neither an abnormality in p13 or n23 latencies nor a cVEMPs amplitudes[34].

There are several different reports on VM patients to show peripheral vestibular dysfunction as the underlying mechanism of cVEMP abnormalities . Taylor et al., reported caloric profile of the VM patients was also normal [33]. On the other hand, there are studies reported caloric abnormalities in 20-25% of migraine patients with vertigo [12, 34-35]. However, there was no correlation between cVEMP and caloric test abnormalities.

Boldingh et al has also found out that 44% of the patients with VM had bilateral or unilateral none-response cVEMP scores[21]. In one of the most recent studies, performed by Hong et al., bilaterally absent cVEMPs have been reported in 41.9% of the controls and 60% of patients with migrainous vertigo [16]. Similarly, in our study we recorded that unilateral or bilateral absence in cVEMP responses in 37% (n:12) patients of group 1 (VM). In 3 patients right sided, in other 3 patients left sided and in 6 patients bilateral absence of responses were obtained. In these patients ABR and cVEMP responses were recorded simultaneously. When findings were compared with controls, there was 0.5 ms delay in wave V peak latency between two sides and this finding is compatible with cVEMP. Bilateral ABR responses were >6ms in patients with bilateral lost cVEMP responses. The location of the sacculocollic pathway is very close to brainstem, and it is thought that abnormalities in cVEMP were concurrent with the dysfunction of brainstem mechanism. When the cVEMP, p13-n23 amplitudes of group 1 (VM) in attack and attack free periods were examined there was a statistically significant decrease in attack period (right side p<0.01 and left side p<0.01).

In our study, when we examined the cVEMP p13-n23 amplitude values during attack period, there were statistically significant differences between all groups. When the groups were examined in pairs , cVEMP and p13-n23 amplitude values of group 1 (VM) was significantly lower than other groups (right side p<0.05 and left side p<0.05). However, there were no significant difference concerning the cVEMPs responses, p13 and n23 latency scores. When we compared wave V latency duration of ABR, there were statistical significant differences. Group 1 wave V peak latency was prolonged significantly in contrast to control group (p<0,05)

CONCLUSION

To date there has been no paper published studying cVEMP and ABR responses simultaneously in attack and attack-free period of VM patients to understand the disease pathophysiology. In our study, in VM patients (37%) whose cVEMP were bilateral or unilateral negative; in accordance with the cVEMP responses, wave V peak latency was prolonged significantly when compared to control group. When we evaluated cVEMP and ABR values of the VM patients in attack and attack free period, there were statistically significance differences between periods. When cVEMP and ABR analyzed together, VM cases for attack and attack free period showed certain changes that display a statistical significance. We thought that the cVEMP and ABR examination records of the patients with vestibular migraine for attack and attack free period may be used as diagnosis criteria.

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Table 1. Demographic data of all groups

Table 2. Values of cVEMP p13-n23 amplitudes of participants (μv)

Table 3. Right and left average wave V peak latencies in all groups (p>0.05, p>0.05)

Figure 1. Right side cVEMP p13-n23 amplitude results for all groups. The cVEMP p13-n23 amplitudes in group 1 were significantly lower than in other groups (p<0.05). M: migraine, VM: vestibular migraine

Figure 2. Left side cVEMP p13-n23 amplitude results for all groups. The cVEMP p13-n23 amplitudes in group 1 were significantly lower than in other groups (p<0.05). M: migraine, VM: vestibular migraine

Figure 3. cVEMP p13-n23 amplitudes of vestibular migraine patients during attack and attack-free periods (right side p<0.01, left side p<0.01). VM: vestibular migraine

Figure 4. Mean latency values of right side wave V for all groups

Figure 5. Mean latency values of left side wave V for all groups