Early Post-Traumatic Seizures in Moderate to Severe Pediatric Traumatic Brain Injury: Rates, Risk Factors, and Clinical Features

Abstract

We performed a retrospective, observational study at a level I pediatric trauma center of children with moderate-to-severe traumatic brain injury (TBI) from January 2002 to September 2006 to identify clinical and radiographic risk factors for early post-traumatic seizures (EPTS). Two hundred and ninety-nine children ages 0-15 years were evaluated, with 24 excluded because they died before the initial head computed tomography (CT) was obtained (n=20), or because their medical records were missing (n=4). Records were reviewed for accident characteristics, pre-hospital hypoxia or hypotension, initial non-contrast head CT characteristics, seizure occurrence, antiepileptic drug (AED) administration, and outcome. All care was at the discretion of the treating physicians, including the use of AEDs and continuous electroencephalogram (EEG) monitoring in patients receiving neuromuscular blocking agents. The primary outcome was seizure activity during the first 7 days as determined by clinician observation or EEG analysis. Of the 275 patients included in the study, 34 had identified EPTS (12%). Risk factors identified on bivariable analysis included pre-hospital hypoxia, young age, non-accidental trauma (NAT), severe TBI, impact seizure, and subdural hemorrhage, while receiving an AED was protective. Independent risk factors identified by multivariable analysis were age <2 years (OR 3.0 [95% CI 1.0,8.6]), Glasgow Coma Scale (GCS) score ≤8 (OR 8.7 [95% CI 1.1,67.6]), and NAT as a mechanism of injury (OR 3.4 [95% CI 1.0,11.3]). AED treatment was protective against EPTS (OR 0.2 [95% CI 0.07,0.5]). Twenty-three (68%) patients developed EPTS within the first 12 h post-injury. This early peak in EPTS activity and demonstrated protective effect of AED administration in this cohort suggests that to evaluate the maximal potential benefit among patients at increased risk for EPTS, future research should be randomized and prospective, and should intervene during pre-trauma center care with initiation of continuous EEG monitoring as soon as possible.

Incidence of seizures on continuous EEG monitoring following traumatic brain injury in children

“…Seventy-one percent of this cohort (102 patients) had moderate or severe TBI (initial GCS score of 3-12) and therefore underwent cEEG monitoring according to the protocol, whereas 25% (36 patients) had mild TBI (GCS score of [13][14][15]. In 4% the initial GCS score was not recorded in the database (Table 1).…”

“…2,6,13,15,17,19 Continuous electroencephalography (cEEG) is the only test to definitively diagnose subclinical seizures. It additionally offers a continuous record of any seizure activity that may have otherwise gone unwitnessed.…”

“…In addition to the moderate and severe TBI cases, continuous EEG monitoring was applied in instances of mild TBI (GCS score [13][14][15] at the discretion of the treating services. This most commonly occurred when clinical seizures were witnessed or when subclinical seizures were suspected.…”

Nonconvulsive Seizures of Traumatic Brain Injury Patients

“…8,11) In patients with TBI, seizures during acute period could be a stimulus for secondary injury, causing poor outcome and high mortality rate. [9][10][11] Therefore prompt diagnosis and treatment of seizures are important for patients with TBI, especially during the acute period. Our study showed that the rate of SDH was high among NCS and 'suspicious NCS' patients, and most of seizures occurred postoperatively.…”

“…Because NCS occurs with a high frequency in case of TBI, the prompt EEG monitoring should be performed for the diagnosis when NCS is suspected. 2,[9][10][11] In case of NCSs, non-coma inducing agents such as IV fosphenytoin and intermittent benzodiazepines could be used in addition to the oral AEDs such as valproate, levetiracetam, and topiramate. 6) All patients in our study…”