Tooth brushing may trigger seizures in certain people with epilepsy according to an article published in the last month's issue of Neurology, the journal of the American Academy of Neurology.

Researchers say lesions in a specific part of the brain may be a cause in some people and the article reviewed the cases of three adults with epilepsy who experienced seizures while brushing their teeth. Two of the adults reported some of their seizures occurred when they brushed certain areas of their mouth. The seizures varied from jerking and twitching of the face to salivating vigorously. One patient was unable to let go of the toothbrush during the seizure. The seizures were confirmed by video monitoring.

Using MRI scans, researchers found all three patients had lesions in the somatosensory area of the brain, which is close to the hand and speech motor areas. 'The rhythmic act of brushing teeth may excite an already overly excitable area of the brain and is similar to photosensitive epilepsy, which involves seizures triggered by flashing lights and moving patterns,' said study author Wendyl D'Souza, who is with the Department of Neurology and Neurological Research at St Vincent's Hospital, the University of Melbourne, Australia.

He added that since tooth brushing involved persistent rhythmic action, this may explain why this trigger is more likely to induce seizures in the somatosensory area of the brain compared to other oral stimuli, such as eating.