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

Objective: 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.

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.