Abstracts

Rationale: Oral laceration injuries are widely recognized as potential complications of convulsive seizures. The predictive value for epilepsy in cases of tongue biting is well documented, but comparatively little is known about the frequency of tongue biting or its relationship to seizure semiology or lateralization. A prior report ascribed a lateralizing value to lateralized tongue biting, but a small sample made clinical applicability uncertain. Due to patient volume and continuous monitoring, systematic seizure assessment in a monitoring unit provides an ideal tool to study seizure semiology and some types of seizure-related complications. As systematic evaluation of oral bites has been added to our seizure assessment protocol, it was decided to harvest that data to provide a comprehensive evaluation of ictal biting injuries.Methods: Chart review was performed for all adults admitted to the Cleveland Clinic epilepsy monitoring unit between February 2014 and February 2015. Cases of oral lacerations were identified by review of nursing seizure assessment notes, which include a systematic evaluation of oral injuries. Patients' demographic data, epilepsy characteristics and seizure characteristics were collected from the electronic medical record and review of the seizure video and EEG. Cases of lateral tongue biting were then selected, and first event of lateralized tongue biting was evaluated to correlate with selected epilepsy- and seizure-related characteristics. Select patients with lateralized tongue biting while in a recumbent position were further evaluated to eliminate the contribution of position.Results: Over 13 months, 89 events of oral lacerations were reported in 52 individuals, for a prevalence of 5.6% of all monitoring unit admissions, 8.3% if excluding patients with only non-epileptic seizures. 88 of these injuries were reported in epileptic seizures, with 57 affecting the tongue and 49 being unilateral. 1 injury was during a non-epileptic seizure and involved the tip of the tongue. Of 88 epileptic seizures associated with a laceration, 80 were primarily or secondarily generalized, 3 were focal, and the others occured in seizure clusters comprising both focal and secondarily generalized seizures. 87/88 had a tonic component and 86/88 had a clonic component. 30/52 patients had lateralized tongue biting. The side of the injury correlated strongly with the dependent side. There was no correlation with handedness or side of clinical or electrographic seizure onset. This remained true when analyzing only the patients who had a seizure while recumbent.Conclusions: Oral laceration is a common complication in the epilepsy monitoring unit. While it is impossible to know when in the seizure the injury occurs, tonic and/or clonic movements were seen in all but one cases and are probably required features. Lateralized tongue biting was previously shown to correlate well with epileptic seizure. Unfortunately, and contrary to previous report, the side of tongue biting could was not associated with any feature related to the epileptic process, instead correlating strongly with patient position during the seizure.