Ictal biting injuries in the epilepsy monitoring unit, a cohort study of incidence and semiological significance

Purpose: Oral biting injuries are widely recognized complications of seizures. Value in differentiating epileptic vs paroxysmal non-epileptic seizures is well demonstrated, but frequency and semiological value are poorly described. We aimed to evaluate frequency in an epilepsy monitoring unit setting as well as semiological value. Material and methods: Systematic evaluation of ictal oral injuries was provided by the nursing staff on the Epilepsy Monitoring Unit. Cases were identified by chart review. Demographic, diagnostic and seizure-related data were collected from medical records and video-EEG recording, and correlated with location of tongue laceration. Lateralized oral lacerations while recumbent were further analyzed to eliminate contribution of body position. Results: 89 events were reported in 52 individuals (5.6% of all admissions or 8.3% of patients with epileptic seizures). Lacerations occurred in 88 epileptic seizures (80 generalized, three focal, five undetermined) and one non-epileptic seizure. 87/88 had a tonic component and 86/88 had a clonic component. Lateralized tongue laceration occurred in 30 patients. This correlated with body position during the event but not with handedness or seizure characteristics. Conclusions: Oral biting is a common complication in the epilepsy monitoring unit. Its presence suggests a tonic or clonic component but is of no help in localizing seizure onset.