The present study found a number of specific brain areas that may be activated by otolith stimulation. Given the findings and source localization techniques (which required limited input from the investigator as to where the sources are believed to be located in the brain) used in the present study as well as the similarity in findings between studies employing galvanic stimuli, fMRI (functional magnetic resonance imaging), and scalp-recorded potentials in response to VEMP-eliciting stimuli, our study provides additional evidence that these brain regions are activated in response to stimuli that can be used clinically to evoke the VEMP.

The present experiment provided a direct comparison of the cVEMP in response to AC versus BC 500 Hz short-duration toneburst stimuli in the same subjects. The results of the present experiment also provide insight into the laterality of the cVEMP response and reveal that the cVEMP may not be completely ipsilateral (i.e., there may be a form of bilateral interaction that occurs when both sides are stimulated simultaneously). Last, the results indicate that BC stimuli likely activates the saccule as well as the utricle, given that AC VEMPs can be masked by the administration of BC masking noise presented to the midline.

The results revealed that a moderate amount of caffeine does not have a clinically significant effect on the results from caloric and cVEMP tests in young healthy adults. Future research is necessary to determine whether similar results would be obtained from individuals with a vestibular impairment, as well as older adults.

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