On Light-induced Sneezing

Purpose: To investigate whether the tickling inside the nose before a light-induced sneeze in susceptible individuals is correlated to a recordable local activity or not.

Methods: Seven healthy volunteers, three with a history of light-induced sneezing, were stimulated with stroboscopic light or a strong halogen lamp. Recording was done with an evoked potential averaging technique via intranasal electrodes placed in such a way that they substantially reduced the strong electrical response from the retina.

Results: Despite an adequate light stimulus, no reproducible electrical activity could be recorded from any of the members in any experiment.

Conclusion: Light-induced sneezing is presumably a central phenomenon. The electrical activity travels through the optic pathways straight to the trigeminal nucleus and the tickling is a referred sensation. A genetic variation in the distance between the optic pathways (colliculus superior) and the mesencephalic part of the trigeminal nucleus may explain why light-induced sneezing is more common in certain families and races.