Turkish Journal of Medical Sciences

Author ORCID Identifier

AYŞEGÜL GÜNDÜZ 0000-0003-2365-0850

TUBA CERRAHOĞLU ŞİRİN 0000-0003-4412-8105

PINAR BEKDİK ŞİRİNOCAK 0000-0002-4644-6572

TUBA AKINCI 0000-0001-8521-7003

BURCU NURAN ARKALI 0000-0002-8789-972X

FATMA CANDAN 0000-0001-8936-5134

MERAL E. KIZILTAN 0000-0003-0538-3736




Background/aim: In this study, we investigated the blink reflex (BR) after simultaneous and asynchronous stimulation of two trigeminal nerve branches. The objective was to characterize the physiology of trigeminal and facial circuits.Materials and methods: We performed three sets of experiments: recording BR response i. after supraorbital nerve stimulation (SON), after mental nerve stimulation (MN), and after simultaneous SON and MN stimulation (SON+MN) in 18 healthy individuals; ii. after MN (at an intensity eliciting BR response) preceding SON at various interstimulus intervals (ISIs) in seven healthy subjects; iii after MN (at sensory threshold) preceding SON at various ISIs. We compared the magnitudes of early and late responses.Results: The R1 amplitude after simultaneous SON+MN stimulation was greater than responses after single stimulation of the same branches. After simultaneous stimulations, the R2 and R2c areas under the curve (AUC) were smaller than the arithmetic sums of R2 and R2c AUC obtained after single stimulations. The second experiment provided a recovery excitability curve. In the third step, we obtained facilitation of R1 and inhibition of late responses.Conclusion: The SON+MN stimulation caused an increased R1 circuit excitability compared to the arithmetic sum of the single stimulations; however, magnitudes of late responses did not potentiate. Thus, we have provided evidence for R1 circuit enhancement by simultaneous stimulation in humans, whereas modulation of late responses exhibited a recovery curve similar to that shown for paired SON stimulation.


blink reflex, mental nerve, recovery curve, Simultaneous stimulation, supraorbital nerve, trigeminal nerve

First Page


Last Page


Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.