Facio-mandibular myoclonus: a rare cause of nocturnal tongue biting.

Facio-mandibular myoclonus is a parasomnia characterized by forceful myoclonus of masticatory muscles in sleep. This condition typically presents with recurrent nocturnal tongue biting, which can be misdiagnosed for nocturnal seizures. The use of surface electromyographic channels over the facial muscles during video-EEG monitoring is helpful in confirming the diagnosis based on a typical burst pattern. This case report highlights difficulties in the diagnosis of facio-mandibular myoclonus and useful features which differentiate it from similar conditions.