Predictors of abnormal findings of computed tomography of the head in pediatric patients presenting with seizures.

OBJECTIVE

To develop a preliminary clinical decision guideline, using characteristics of ED pediatric patients presenting with seizures, that successfully predicts all abnormal results of computed tomography (CT) of the head.

METHODS

We assembled a retrospective case series in the ED of a tertiary care children's hospital without trauma designation. The series comprised all patients who presented between January 1, 1992, and December 31, 1994, with seizures (febrile and afebrile) who underwent head CT as part of ED evaluation.

RESULTS

Our inclusion criteria were met by 203 patients. Of these patients, who had a median age of 3.1 years, 53% were boys; 18% had been transferred from another facility; 25% had received anti-convulsant medication in the field, at the referring facility, or both; 32% had a history of seizures before the presenting episode; 6% had sustained a closed-head injury (CHI); 15% had a cerebrospinal fluid (CSF) shunt; 4% had an underlying malignancy or neurocutaneous disorder (NCT); and 30% had a documented fever. CT findings were abnormal in 25 patients (12%). CT showed evidence of hemorrhage in eight patients (32%), small focal abnormalities in four (16%), cerebral edema in three (12%), and shunt obstruction in two (8%). chi 2 Recursive-partitioning analysis revealed that CT scan results were always normal when the patient did not have an underlying high-risk condition (malignancy, NCT, recent CHI, or recent CSF shunt revision), was older than 6 months, had sustained a seizure of 15 minutes or less, and did not have a history of a new-onset focal neurologic deficit. Retrospective application of these criteria revealed that 41% of the CT scans could have been deferred.

CONCLUSIONS

In this case series, the absence of defined high-risk factors predicted normal head CT findings. The deferral of emergency CT in this population should be considered.