Abstracts

Rationale: Traumatic brain injury (TBI) is a well-known risk factor for epilepsy. The occurrence of seizure following TBI can be associated with poor functional outcome. We aimed to identify the frequency and risk factors for seizure occurrence during hospitalization for TBI and determine the impact of seizures on outcome.Methods: All patients with age ³ 18 years who were admitted with traumatic brain injury were identified by ICD-9-CM codes from the National Trauma Data Bank (NTDB), using data files for 2009 and 2010. NTDB is one of the largest trauma databases and contains data from over 900 trauma centers across the U.S. Occurrence of seizures during hospitalization was identified by using ICD-9-CM codes. Patients’ demographics, comorbidities, admission Glasgow Coma Scale (GCS), Injury Severity Score (ISS), in-hospital complications, and discharge disposition were compared in the seizure group (SG) and the no-seizure group (NSG).Results: A total of 790 patients had in-hospital seizures which comprised 0.2% of all patients admitted with traumatic brain injury. The mean age for SG was 4 years older than NSG [52.89 (51.67-54.13) versus 48.25 (48.18-48.32); p<.0001]. African-American ethnicity (23% versus 12%, p<.0001) and moderate TBI (7% versus 4%, p=0.003) were more common in SG, whereas the total injury severity score was lower in SG [12.73 (12.15-13.31) versus 14.78 (14.74-14.82), p<.0001]. SG more commonly had history of alcohol dependence (24% versus 11%, p<.0001). Fall was the most common mechanism of injury in SG occurring in 58%, compared with 36% in NSG (p<.0001). Subdural hematoma was more common in SG (29% versus 21%, p<.0001). SG had higher rates of pneumonia, ARDS, acute kidney injury, and increased ICP. SG had higher rates of CNS infections (1% versus 0.01%, p<.0001) and blood product transfusion (14% versus 6%, p<.0001). The two groups had similar rates of craniotomy and decompression of skull fracture. The average length of ICU stay and ventilator days were not different between the two groups. The average length of hospital stay was significantly higher in SG (8 days versus 6 days, p=0.0002) and these patients had higher rate of discharge to nursing facility (31% versus 24%, p<.0001). The difference in length of hospital stay [1.39 (1.14-1.85), p=0.008] and discharge to nursing facility [1.24 (1.05-1.47), p=0.02] remained statistically significant after adjusting for demographics, GCS score, injury severity, mechanism of injury, subdural hematoma and in-hospital complications.Conclusions: In-hospital seizures occur in 0.2% of all TBI patients. Fall and subdural hematoma are strong predictors of seizure in these patients. Although infrequent, seizures are associated with increased rate of hospital complications such as pneumonia and ARDS and it is an independent predictor of longer hospital stay and worse hospital outcome.