A scoring chart to evaluate cases of probable vestibular migraine

Abstract

Objectives

To suggest a chart for the diagnosis of probable vestibular migraine for cases that cannot fit the internationally agreed diagnostic criteria.

Methods

This retrospective study enrolled patients who presented with chronic dizziness and attacks of severe vertigo in whom the diagnostic criteria for diagnosing probable vestibular migraine were not applicable, and there was no possibility to account for other vestibular diagnoses. The trial of vestibular migraine treatment was started without any labyrinthine sedatives for a month. Patients whose conditions improved and were vertigo free for the trial period were included in this study. Common complaints, clinical examination findings, and hearing and vestibular test results were analyzed. Findings observed in more than 50% of the included patients were added to a chart. The chart was implemented with a score and included female gender, bilateral tinnitus, aural fullness, significant headache, family history of migraine, and reported hypotension. Any one of them increased the score by one point, while bilateral low frequencies sensorineural hearing loss and bilateral frequency tuning of cervical vestibular evoked myogenic potentials increased the score by two points.

Results

All the patients had a score of 5 or more.

Conclusion

The diagnostic chart is useful for suggesting probable vestibular migraine in cases that do not comply with the internationally agreed diagnostic criteria.

Keywords:

• Bilateral low frequency sensory neural hearing loss
• bilateral tuning of cervical vestibular evoked myogenic potentials
• dizziness
• vertigo

Introduction

Vestibular migraine (VM) is a well-known cause of dizziness and vertigo; it can be described as migraine-associated vertigo, migraine-related vestibulopathy, migrainous vertigo, and vertiginous migraine [1]. The cause of VM is unknown, and the mechanism of the pathophysiologic process is still not fully understood [1]. VM is the second most common cause of vertigo [2] and is more common in females, with male to female ratio of 1:5 [3].

Despite the clear diagnostic criteria of VM and probable VM, according to a joint statement by the International Headache Society and the Barany Society [4], diagnosing this disease can be challenging. This is because vestibular symptoms often occur independently of migraine headache, and the manifestations may be similar to other syndromes of positional and spontaneous episodic vertigo [1]. Accordingly and as reported by many authors, many vertigo patients with migrainous features do not meet the agreed diagnostic criteria for VM [5]. In some cases, the diagnosis can only be made by exclusion and based on positive treatment response to migraine dietary and lifestyle advice and migraine medication as a clear definition of migraine before VM is insufficient in such cases. Reviewing the literature shows that there is no specific diagnostic test for VM and that diagnosis relies on the clinical history and normal results of investigations and vestibular tests that are usually conducted to exclude other peripheral or central disorders.

Cases showing good response to migraine treatment showed common complaints (bilateral tinnitus, non-specific and recurrent headache, unilateral or bilateral aural fullness, pain or heaviness, and family history of migraine) and also showed common findings in some audio-vestibular tests [bilateral low frequencies sensorineural hearing loss (LFSNHL) in pure tone audiograms and bilateral frequency tuning to 750 Hz or 1000 Hz by cervical vestibular evoked myogenic potentials (cVEMPs)]. The history of those patients also shows the presence of hypotension in the 2nd and 3rd decades of life in patients older than 35 years and current instances of hypotension for patients under 35 years. There was also a family history of migraine in a high percentage of those patients.

These common manifestations and findings may help diagnose this problem and help start treatment. This study aimed to suggest a chart for the diagnosis of probable VM for cases that do not fit the internationally agreed diagnostic criteria.

Materials and methods

This retrospective study was approved by the institutional review board (no. 779). We reviewed findings in history, clinical examination and vestibular laboratory testing of the patients who presented at the specialty ENT and Balance Centre with attacks of chronic dizziness and severe vertigo and that the diagnostic criteria of Probable VM were not applicable and there was no possibility to account for another diagnosis; trial treatment of VM was started, including dietary restrictions, sleep and lifestyle regulations and migraine prophylactic medication (amitriptyline 10 mg per day for 1 month). No labyrinthine sedatives were used during that month. The patients’ condition was re-evaluated after the trial period; patients whose general condition improved and were vertigo free for the trial period were included in this study. Exclusion criteria were:

1. Patients with history of development of any attack of vertigo during the trial period.

2. Patients with history of non-compliance or poor compliance of dietary restrictions, sleep and life style regulations or medication during the trial period.

3. Patients with history showing that they were known cases of migraine.

4. Patients with history showing that they have Diabetes mellitus.

Accordingly, 25 patients were included, and their common complaints, findings in the clinical examinations, and hearing and vestibular tests were collected and analyzed statistically. Any one of these findings present in more than 50% of the included patients was added to a chart. The implemented scoring chart of findings was applied retrospectively to all the included patients (Table 1).

Table 1. Suggested scoring chart for probable vestibular migraine.

Clinical finding	Score
Female gender	1
Bilateral low frequencies SNHL by PTA	2
Bilateral frequency tuning to 750 or 1,000 Hz by cVEMPs	2
Bilateral tinnitus	1
Unilateral or Bilateral aural symptoms ( pain , fullness or heaviness)	1
Chronic headache	1
Family History of migraine	1
Reported Hypotension or history of hypotension	1
Total	10

Chronic headaches not diagnosed before as part of migraine, unilateral or bilateral, aural complaints like fullness, heaviness or otalgia, and bilateral tinnitus were part of the scoring chart; when any one of them was reported by a patient, one point was added to the scoring chart.

Low blood pressure at presentation and a history of hypotension were also included in the scoring chart. Low blood pressure (<90 mmHg systolic pressure or <60 mmHg diastolic pressure) reported in the past records of the patient or hypotension at presentation increased the score by one point after ruling out the presence of any medication that can induce hypotension. As migraine-associated diseases are more common in females and usually run in families, the female sex added one point to the scoring chart. This also applied to the presence of a family history of migraine.

Bilateral slight or mild LFSNHL in the pure tone audiograms was also noted (Figure 1). Although some patients were without hearing deficit, when there was bilateral low frequency worse than high frequencies by 15 dB or more and the high-frequency area was within normal limit reported bilaterally in the pure tone audiogram at presentation or any of the series of old audiograms of the same patient when present, two points were added to the scoring chart.

Figure 1. Example of typical bilateral low-frequency sensorineural hearing loss present in 16 patients included in the study.

Bilateral frequency tuning of the highest peaks of cVEMPs towards 750 or even 1000 Hz (Figure 2) was also noted and added to the chart. When the highest peaks were reported in 750 or 1000 Hz bilaterally (not in 500 Hz as in normal subjects) and the ratio of the amplitude at 500/1000 Hz or 500/750 Hz was 0.9 or less in cVEMPs study of the patient at presentation or in old cVEMPs study when present, two points were added to the scoring chart. The idea of adding two points for bilateral LFSNHL and bilateral tuned cVEMPs findings stemmed from the fact that these tests cannot be affected by the patient’s psychological state.

Figure 2. Example of typical cVEMPs tuning where the highest amplitude of P13 to N23 peaks is shifted to 750 Hz or 1000 Hz bilaterally present in 16 patients included in the study.

Other abnormal findings in vestibular testing, like some abnormalities in smooth pursuit eye movement recording and abnormal spontaneous nystagmus, were also reported in the patients included in this study. However, the incidence of these abnormal findings was less than 50% of the studied sample and was not added to the chart.

Results

In total, 9 males and 16 females were studied (25–53 years old, the median age was 32 years). Most of the selected clinical findings and hearing and vestibular testing were present in all the patients included in the study in various percentages (Figure 3). Score of each patient included in the study with individual findings according to the scoring chart is presented in Table 2. Applying the suggested scoring chart of all 25 patients included in this study, as shown in Table 2, demonstrates that all patients included had a score of 5 or more, and 84% of the patients had a score of more than 5.

Figure 3. Percentages of the reported components of the scoring chart of probable vestibular migraine in the patients included in the study.

Table 2. Scoring chart of probable vestibular migraine with findings of the patients included in the study with the resulted scores.

Patient No.	Age	female gender	Bilateral LFSNHL [I]	Bilatreral tunned cVEMPs [II]	Bilateral tinnitus	Uni. or Bi. aural symptoms [III]	chronic headache	Family Hx. Migrane [IV]	low B.P. [V]	Score
1	27	y	n	n	n	y	y	y	y	5
2	34	y	n	y	n	n	y	n	y	5
3	30	n	n	y	y	y	n	y	n	5
4	44	n	n	y	y	y	y	n	n	5
5	48	Y	n	n	y	y	y	y	y	6
6	53	y	y	n	y	n	y	n	y	6
7	25	n	y	n	y	y	y	n	y	6
8	27	n	y	n	y	y	y	n	y	6
9	36	n	n	y	y	n	y	y	y	6
10	35	n	y	y	n	y	n	n	y	6
11	28	y	n	y	n	y	y	n	y	6
12	37	y	y	n	y	n	y	y	y	7
13	27	y	y	y	n	n	y	n	y	7
14	32	y	y	n	n	y	y	y	y	7
15	25	n	y	n	n	n	n	n	n	7
16	39	y	y	n	n	y	y	y	y	7
17	28	y	n	y	n	y	y	y	y	7
18	35	y	y	y	n	y	n	y	y	8
19	48	n	y	y	y	y	y	y	n	8
20	26	n	y	y	y	y	y	y	n	8
21	41	y	n	y	y	y	y	y	y	8
22	25	y	y	y	y	n	y	n	y	8
23	27	y	y	y	y	y	y	n	y	9
24	35	y	y	y	y	y	y	n	y	9
25	33	y	y	y	n	y	y	y	y	9

Y: Yes; n: No.

[I] Bilateral Low Frequencies Sensori-Neural Hearing Loss.

[II] Bilateral tuned cervical Vestibular Evoked Myogenic Potentials towards frequencies higher than 500 Hz.

[III] Unilateral or Bilateral aural symptoms like aural fullness, aural heaviness or aural pain.

[IV] family History of Migraine.

[V] low Blood Pressure (hypotension).

Discussion

According to a joint statement by the International Headache Society and the Barany Society [4], VM can be either definite or probable. Even with probable VM, some cases can be encountered clinically that do not meet the agreed criteria and cannot be counted in other diagnoses and trials of migraine treatment can improve the complaint of these patients dramatically. Risbud et al. [6] stated that the diagnostic criteria for definite and probable VM may be too stringent and exclude many patients from potentially benefitting from treatment with migraine prophylaxis.

Most of the patients in this study complained of aural fullness, heaviness, or ear pain (72% of included patients). Moshtaghi et al. [7] suggested in their study that there is an aetiological association between migraine and prolonged aural fullness, which support the idea of inclusion of aural fullness in the suggested scoring chart. All the patients with aural fullness in this study responded to migraine treatment, similar to the findings of Moshtaghi et al. [7]

In total, 56% of the cases included in this study had bilateral tinnitus. Kırkım et al. [8] reported that tinnitus was a common complaint of patients with VM while it was not in patients with migraine. Hwang et al. [9] showed that the risk of tinnitus is higher among patients with a history of migraines. Nowaczewska [10] also reported a higher incidence of bilateral tinnitus in migraine patients, supporting the findings of this study.

Chronic headache was the most common complaint in the patients in the study, with a percentage of 84%. Those patients may already have migraine which was not diagnosed before and proceeded to VM or have a headache as a part of a newly developed VM. Direct questions about the association of headaches with photophobia, phonophobia, or features of aura may be important. Wattiez et al. [11] reported that patients with VM are more likely to have occipital headaches than patients with migraine without vestibular symptoms. Beh et al. [12] concluded in their single-center study that VM usually presented with spontaneous vertigo associated with photophobia and phonophobia, nausea, aural symptoms, and headache, which also supports the findings of this study.

Migraine is well recognized as a familial disorder, and there are documented pedigrees of families with VM [13]. Only 52% of cases included in this study had a family history of migraine, possibly due to under-diagnosis of this problem by the general practitioners and specialists other than neurologists and neuro-otologists. Yeh et al. [14] mentioned that migraine prevalence is significantly higher with neurologists than non-neurologists and at least two to three times higher than reported in population prevalence studies that support this suggestion.

Despite female preponderance, the literature showed different male-to-female ratios. Byun et al. [15] reported a ratio of 1:2.1. Neuhauser and Lempert [16] reported a ratio of 1:3, while Lempert and Neuhauser [3] reported 1:5. All these ratios were less than what was found in this study, which was 1:1.7. This high ratio may be due to the small study group, but it is also beneficial to be included in the scoring chart.

In this study, 20 out of 25 patients had hypotension at presentation or a history of hypotension. Hypotension in migraine patients is well reported in the literature dealing with similar conditions [17,18].

VM is associated with fluctuating sensorineural hearing loss that involves the low-frequency range [19]. Radtke et al. [20] reported that 18% of the patients developed mild bilateral LFSNHL, while 64% of the patients included in this study had slight or mild bilateral LFSNHL in the pure tone audiograms that were reviewed. The idea of reviewing any available old audiograms for the same patient came from the fact of VM is associated with fluctuations in the hearing level that leads to the possibility of missing the state of LFSNHL at one presenting point. That could be the cause of the low reported rate of this pattern of hearing loss in other literature. Different patterns of hearing loss can be associated with VM, flat, low frequency, high frequency, bilaterally symmetrical, bilaterally asymmetrical, and unilateral hearing loss [21]. As the state of bilateral LFSNHL has a unique association with VM, adding it to the chart and using it to hint at the diagnosis seems helpful and interesting. Thus, two points were added to the scoring system for patients that presented with it.

Interestingly, 64% of the patients in this study reported bilateral tuning of cVEMPs amplitudes to 750 or 1000 Hz. This phenomenon can occur in elderly people [22] and unilaterally in Meniere’s disease (MD) [22,23]. The relationship between VM and MD is well reported in the literature [24]. Salviz et al. [25] also reported that overlaps could be seen between VM and MD, and diagnosis is difficult when hearing is normal. They identified that in patients with VM, p13 and n23 latencies of cVEMPs were similar to healthy controls, but peak-to-peak amplitudes were bilaterally reduced at 500 Hz tone bursts.

In contrast, in MD, asymmetrically reduced amplitudes on affected ears with low response rates at 500 Hz tone bursts. These findings support using cVEMPs in the scoring chart suggested by this study as none of the patients included was elderly; the oldest patient included was 53 years, and the median age was 32 years. Also, Salviz et al. [25] suggested that bilateral otolith organs are affected by migraine-induced ischaemia that leads to bilateral cVEMPs changes. Frequency tuning of cVEMPs in MD is due to endolymphatic hydrops [22], which is the whole pathophysiological process of that disease. Bilateral endolymphatic hydrops was also reported recently in patients with migraine [26,27]. Bilateral endolymphatic hydrops could be another pathophysiologic explanation of VM that explains the findings of bilateral cVEMPs tuning reported in this study. Bilateral cVEMPs tuning was added to the chart with two point increment when present.

The possibility of primary lack of a correct autonomic regulation as a cause of symptoms of the patients included in the study was rule-out as all the patients were suffering from vertigo rather than only dizziness and syncope which is the usual presenting complaint of the patients of this problem [28], autonomic neuropathy is usually associated with diabetes mellitus [29]; all cases included in this study was non-diabetic which also rule-out this possibility. Martin Mullar and Martin Marziniak [30] also reported a lack of sympathetic and the parasympathetic controls in in migraine patients which also support the inclusion of history of hypotension in the scoring chart suggested by this study as a clue to possibility of possible vestibular migraine.

All the patients included in this single-center study had a score of 5 or more out of 10 on the scoring chart, which seems to be a good predictive method for probable VM (Figure 3). The author suggested that the higher the score, the more the possibility of probable VM, and a score of less than 5 can exclude the disease. However, multi-center studies, prospective large sample size studies, studies applying the same chart with the same scoring system for patients with definite VM, patients with migraine without vertigo and control groups of persons with no complaints may be needed for further confirmation of these results. The chart may be expanded in future studies by adding other commonly identified physical signs in cases of VM, like abnormal horizontal or vertical smooth pursuit and findings of positioning tests.

In conclusion, there are vertiginous patients for whom the internationally agreed diagnostic criteria of probable VM do not apply, and they still benefit from anti-migraine measures and treatment. Also, applying the scoring chart in Table 1 may give a useful hint for diagnosing probable VM for cases that fail to comply with the internationally agreed diagnostic criteria. The higher the score obtained from the scoring chart, the higher the probability of VM. Using the scoring chart cannot confirm the diagnosis but rather can direct the clinicians’ thinking dealing with similar cases to try any anti-migraine measures before shifting to more aggressive therapies.

Acknowledgment

Special thanks to Taylor & Francis Editing Services for English reviewing and editing.

Disclosure statement

No potential conflict of interest was reported by the author(s).