Effects of caffeine on cervical vestibular evoked myogenic potential: a pilot study

Caffeine at low doses blocks adenosine receptors. These receptors are present in all parts of the body including auditory and vestibular system. This study aimed to evaluate the effects of caffeine on cervical vestibular evoked myogenic potential (cVEMP). In this interventional double-blind study, 40 cases (20 females and 20 males) aged 18-25 years were randomly assigned into two groups: the test group, 3 mg/kg caffeine and little sugar and dry milk in 100ml water, and the control group, placebo including sugar and dry milk in 100ml water. Myogenic potential was recorded before and after intervention with 500 Hz tone burst in 95 dBnHL. The statistical analysis revealed that there was no significant difference in p13 and n23 latency and amplitude asymmetry. However, the mean amplitudes of right ear (p=0.04) and two ears (p=0.02) of test group indicated a significant increase after caffeine ingestion. The results showed no significant difference in caffeine group compared to the placebo group in any of parameters and ears (p>0.05). With current study small sample size we found no effect of 3 mg/kg dose of caffeine on cervical vestibular evoked myogenic potential. Although after intervention the significant increase in the amplitude of all samples was notable, no significant difference was found between the two groups. The present study was the first research in this area, however, larger sample size and different doses of caffeine is suggested for future studies.