Nationwide incidence and risk factors for posttraumatic seizures in children with traumatic brain injury
Authors: Rumalla Kavelin , Smith Kyle A. , Letchuman Vijay , Gandham Mrudula , Kombathula Rachana , Arnold Paul M. 
Published: September 2018

OBJECTIVE

Posttraumatic seizures (PTSs) are the most common complication following a traumatic brain injury (TBI) and may lead to posttraumatic epilepsy. PTS is well described in the adult literature but has not been studied extensively in children. Here, the authors utilized the largest nationwide registry of pediatric hospitalizations to report the national incidence, risk factors, and outcomes associated with PTS in pediatric TBI.

METHODS

The authors queried the Kids’ Inpatient Database (KID) using ICD-9-CM codes to identify all patients (age < 21 years) who had a primary diagnosis of TBI (850.xx–854.xx) and a secondary diagnosis of PTS (780.33, 780.39). Parameters of interest included patient demographics, preexisting comorbidities, hospital characteristics, nature of injury (open/closed), injury type (concussion, laceration/contusion, subarachnoid hemorrhage, subdural hematoma, or epidural hematoma), loss of consciousness (LOC), surgical management (Clinical Classification Software code 1 or 2), discharge disposition, in-hospital complications, and in-hospital mortality. The authors utilized the IBM SPSS statistical package (version 24) for univariate comparisons, as well as the identification of independent risk factors for PTS in multivariable analysis (alpha set at < 0.05).

RESULTS

The rate of PTS was 6.9% among 124,444 unique patients hospitalized for TBI. The utilization rate of continuous electroencephalography (cEEG) was 0.3% and increased between 2003 (0.1%) and 2012 (0.7%). The most common etiologies of TBI were motor vehicle accident (n = 50,615), accidental fall (n = 30,847), and blunt trauma (n = 13,831). However, the groups with the highest rate of PTS were shaken infant syndrome (41.4%), accidental falls (8.1%), and cycling accidents (7.4%). In multivariable analysis, risk factors for PTS included age 0–5 years (compared with 6–10, 11–15, and 16–20 years), African American race (OR 1.4), ≥ 3 preexisting comorbidities (OR 4.0), shaken infant syndrome (OR 4.4), subdural hematoma (OR 1.6), closed-type injury (OR 2.3), brief LOC (OR 1.4), moderate LOC (OR 1.5), and prolonged LOC with baseline return (OR 1.8). Surgically managed patients were more likely to experience PTS (OR 1.5) unless they were treated within 24 hours of admission (OR 0.8). PTS was associated with an increased likelihood of in-hospital complications (OR 1.7) and adverse (nonroutine) discharge disposition (OR 1.2), but not in-hospital mortality (OR 0.5). The overall utilization rate of cEEG was 1.3% in PTS patients compared with 0.2% in patients without PTS. Continuous EEG monitoring was associated with higher rates of diagnosed PTS (35.4% vs 6.8%; OR 4.9, p < 0.001).

CONCLUSIONS

PTS is common in children with TBI and is associated with adverse outcomes. Independent risk factors for PTS include younger age (< 5 years), African American race, increased preexisting comorbidity, prolonged LOC, and injury pattern involving cortical exposure to blood products. However, patients who undergo urgent surgical evacuation are less likely to develop PTS.