Abstracts

South Carolina records an average of 12,500 new cases of traumatic brain injury (TBI) annually and 2.9% have a comorbid diagnosis of epilepsy and seizure disorders. Seventy-five percent were treated and released from the Emergency Department (ED). Individuals with epilepsy have an increased risk of injury, with as many as 30% reporting injuries compared to the general population. Of adults with epilepsy in the U.K. who answered questions on injuries sustained from an epilepsy attack, 22.5% reported a head injury in the previous year. In the U.S., patients with seizures may make up almost 1% of all patients seen in an urban ED, with 6% having serious trauma resulting from the seizure. However, there is no concrete, population-based, estimate addressing the rate of TBI among persons with epilepsy. This study examines the relationship between TBI and epilepsy to, 1) determine the occurrence of epilepsy among persons with TBI, 2) identify the seizure types frequently associated with brain injury, 3) characterize the demographic characteristics, and 4) identify the mechanism of injury. We defined TBI using the standard CDC case definition and ascertained cases with ICD-9-CM codes of 800-801, 803-804, 850-854, and 959.01. All persons who visited ED or were admitted to any one of the 62 non-federal hospitals were included in the study. Cases were unduplicated using personal identifiers. Observations with a comorbid diagnosis of 345 and 780.39 were selected as cases. A random sample of 893 observations was selected for detailed medical record review and evaluations. Preliminary analysis indicates that 75,006 individuals were diagnosed with TBI. About 2.9% (2,169) have a comorbid diagnosis of epilepsy and seizure disorders. Most common comorbid diagnosis was seizure not otherwise specified (780.39), followed by grand mal seizures (345.1) and convulsive epilepsy (345.3). In 71% of the records, there was evidence of seizure. Males with seizure were 3 times more likely to experience head trauma than females. Falls were the most commonly recorded mechanism of injury. The rate of occurrence of TBI among persons with seizure disorder is nearly 11 times that of the rate noted in the general population of South Carolina. These preliminary population-based findings suggest that TBI occurs at an alarming rate among persons with epilepsy. Repetitive head injuries are likely to exacerbate the seizure frequency and severity. Further study is needed to assess the specific clinical and behavioral factors that predispose persons with epilepsy to TBI. (Supported by the CDC under Cooperative Agreement # U17/CCU421926)