Background: Vestibular migraine (VM) is considered one of the most common cause of episodic central vestibular disorders, the mechanism of VM is currently still unclear. It is worth investigating whether VM belongs to the migraine subtype or is a separate disorder. The development of functional nuclear magnetic resonance (fMRI) in recent years offers the possibility to explore the pathogenesis of VM in depth. The study aimed to investigate resting-state functional brain activity alterations in patients with VM diagnosed based on the diagnostic criteria of the Bárány Society and the International Headache Society.
Methods: Seventeen patients with VM who received treatment in our hospital from December 2018 to December 2020 were enrolled. Clinical data of all patients were collected. Eight patients with migraine and 17 health controls (HCs) were also included. All subjects underwent fMRI examination. The amplitude of low frequency fluctuation (ALFF), fractional amplitude of low frequency fluctuation (fALFF) and regional homogeneity (ReHo) were calculated to observe the changes in spontaneous brain activity in patients with VM. Then brain regions with altered spontaneous brain activity were selected for seeded-based functional connectivity (FC) analysis to explore the changes in FC in patients with VM.
Results: Among 17 patients with VM, there were 7 males and 10 females with an average age of 39.47±9.78 years old. All patients with VM had a history of migraine. Twelve (70.6%) patients with VM had recurrent spontaneous vertigo, 2 (11.7%) patients had visually-induced vertigo, and 3 (17.6%) patients had head motion-induced vertigo. All 17 patients with VM reported worsening of dizziness vertigo during visual stimulation. The migraine-like symptoms were photophobia or phonophobia (n=15, 88.2%), migraine-like headache (n=8, 47.1%), visual aura during VM onset (n= 7, 41.2%). 5 (29.4%) patients with VM had hyperactive response during the caloric test, and 12 (70.6%) patients had caloric test intolerance. Eleven (64.7%) patients had a history of motion sickness. VM patients showed exhibited significantly increased ALFF and fALFF values in the right temporal lobe (STG and MTG), and significantly increased ReHo values in the right STG, MTG and ITG in comparison with HCs. Compared with patients with migraine, patients with VM showed significantly decreased ALFF values in the right median cingulate and paracingulate gyri, significantly increased fALFF values in the right parietal lobe (postcentral gyrus and superior parietal gyrus), and the right frontal lobe (supplementary motor areas and dorsolateral superior frontal gyrus), as well as significantly increased ReHo values in the right thalamus. Compared with HCs, patients with migraine showed significantly increased ALFF values in the right limbic lobe (right parahippocampal gyrus and right fusiform gyrus), left ITG and the right frontal lobe (supplementary motor areas, right median cingulate and paracingulate gyri, and right right inferior frontal gyrus), significantly decreased ALFF values in the pons and brainstem, significantly decreased ReHo values in the frontal cortex (including left and right supplementary motor areas, left dorsolateral superior frontal gyrus, left median cingulate and paracingulate gyri, right paracentral lobule, right dorsolateral superior frontal gyrus, left and right middle frontal gyrus).
Conclusions: Ventral stream of visual processing and allocentric spatial cognition in patients with VM may be impaired. Vertigo attacks in patients with VM may be related to increased spontaneous activity in the right parietal lobe-frontal lobe-thalamus; patients with VM and migraine both had altered brain function, but the underlying mechanism seems to be different.