[Characteristics of the subtype of vestibular migraine with ear fullness: association with early onset age and low-frequency hearing loss].

Objective

The clinical significance of aural fullness in patients with vestibular migraine（VM） remains unclear, and it is yet to be determined whether VM with aural fullness represents a distinct subtype of VM; this study aimed to compare differences in demographic characteristics, clinical manifestations, audiological findings, and vestibular function tests between VM patients with and without aural fullness, and explore whether the former is a subtype of VM and whether it requires differentiated treatment.

Methods

A total of 174 VM patients were enrolled, including 75 with aural fullness（aural fullness group） and 99 without aural fullness（non-aural fullness group）; demographic data, vertigo characteristics, medical history, family history, pure-tone audiometry, and vestibular function tests were thoroughly recorded, and independent samples t-test and chi-square test were used for inter-group comparisons.

Results

①Regarding demographic characteristics, the age of the aural fullness group was significantly lower than that of the non-aural fullness group[（44.08±13.97） years vs. （49.45±16.05） years, P=0.020）, while the two groups showed consistent gender distribution（more females than males） with no statistically significant difference. ②For aural fullness characteristics, unilateral aural fullness accounted for 65.0% in the aural fullness group, significantly higher than bilateral aural fullness（35.0%, P<0.001）. ③In terms of vertigo characteristics, there were no statistically significant inter-group differences in the nature of attacks（rotational vertigo: 36.0% vs. 41.4%, P=0.463; dizziness: 21.3% vs. 11.1%, P=0.064; rotational vertigo or dizziness: 29.3% vs. 25.3%, P=0.548; dizziness with unsteady gait: 9.3% vs. 11.1%, Fisher P=0.806; visual oscillation with unsteady gait: 4.0% vs. 11.1%, Fisher P=0.086）, duration（several hours: 34.7% vs. 33.3%, P=0.841; several minutes: 22.7% vs. 21.2%, P=0.808; several seconds: 5.3% vs. 8.1%, Fisher P=0.557; several days: 9.3% vs. 9.1%, Fisher P=1.000; multiple combined patterns: 17.3% vs. 15.2%, P=0.686）, or incidence of nausea and vomiting（84.0% vs. 72.7%, P=0.071, no statistical significance）. ④No statistically significant inter-group differences were found in medical history and family history, including motion sickness history（8.0% vs. 4.0%, Fisher P=0.337）, headache history（22.7% vs. 34.3%, P=0.084）, and family history of dizziness（12.0% vs. 14.1%, P=0.666）. ⑤For audiological characteristics, 21.3%（16/75） of patients in the aural fullness group had low-frequency hearing loss, significantly higher than 5.1% in the non-aural fullness group（χ²=10.66, P=0.001）; among patients with unilateral aural fullness, 28.6%（14/49） had ipsilateral low-frequency hearing loss, significantly higher than 7.7%（2/26） of those with bilateral aural fullness（χ²=4.41, P=0.036）; however, there was no statistically significant difference in the rate of bilateral high-frequency hearing loss between the two groups（54.7%[41/75]vs. 50.5%[50/99], χ²=0.30, P=0.586）. ⑥In vestibular function tests, no statistically significant inter-group differences were observed in smooth pursuit type Ⅲ/Ⅳ（12.5% vs. 13.1%, P=0.913）, caloric test with CP>25%（31.2% vs. 37.4%, P=0.411）, abnormal video head impulse test（vHIT） rate（30.8% vs. 32.6%, P=0.865）, or abnormal vestibular evoked myogenic potential（VEMP） rate（53.8% vs. 38.9%, Fisher P=0.484）.

Conclusion

VM patients with aural fullness have an earlier age of onset, with nearly 1/4 accompanied by low-frequency hearing loss; VM patients with and without aural fullness are highly consistent in gender distribution, nature/duration of vertigo, vestibular function impairment, and presence of bilateral high-frequency hearing loss, suggesting that the core clinical phenotypes of the two groups are consistent, while the former has an earlier age of onset and a higher proportion of unilateral hearing loss, which may be related to the pathological mechanism of VM and inner ear microcirculation disorders.