Intermediate latency evoked potentials of cortical multimodal vestibular areas: Acoustic stimulation

•Multimodal vestibular network 3-D EEG dipoles mapped with BESA program.•Specific evoked and induced cortical potentials 20–150 ms.•Corresponding deep brain electrode data in epilepsy patient.

ObjectiveLoud acoustic stimuli at 500 Hz activate the vestibular system. Intermediate-latency vestibular cortical potentials of multimodal cortex regions were investigated, beyond the 20 ms time range.MethodsEighteen healthy subjects with 32-channel EEG and one epilepsy patient with right-sided intracortical electrodes received three types of stimuli: tone bursts capable of evoking vestibular evoked myogenic potentials (VEMP) in neck muscles and sham stimuli matched for either frequency or amplitude, which cannot evoke myogenic responses.ResultsVEMP-capable stimuli activated anterior insula and posterior operculum bilaterally at 20, 30, 60 and 110 ms, frontal brain regions at 70 and 110 ms, determined by Brain Evoked Source Analysis BESA. Recordings from intracranial electrodes revealed corresponding peaks at identical latencies. Stimulus-locked high and low beta and mu band modulations were found in vestibular, parietal and occipital regions, beyond 20 ms. Sham stimuli only evoked late acoustic potentials. Corresponding vestibular potentials were also seen in an eight-channel bipolar Laplacian montage.ConclusionsThe sequentially appearing cortical potentials evoked by VEMP-capable stimuli co-locate with data from functional imaging studies. Frequency-specific activity (induced potentials) in these areas may reflect multimodal proprioceptive and visual sensory crosstalk.SignificanceVestibular cortical evoked potentials may see clinical use in vertigo disorders.