Abstracts

Rationale: Febrile seizures are the most common cause of convulsions and affects 2-5% of children. They are categorized as either simple or complex depending on their clinical features. For simple febrile seizures, the American Academy of Pediatrics recommends minimal investigations apart from considering lumbar puncture when clinically indicated. No clear guidelines exist for evaluation of complex febrile seizures (CFS). The rationale behind this retrospective study is to identify the yield of electroencephalography (EEG) and magnetic resonance imaging (MRI) in children presenting with CFS to a tertiary medical center, and to help determine if a particular type of CFS is associated with higher rate of abnormalities. Further, this data may help develop specific guidelines for diagnostic work-up of CFS. Methods: We conducted an electronic medical record search for children between ages of 1 month to 6 years who presented to our center with a diagnosis of CFS between January 2005 and May 2013. Patients with preexisting neurological disorders, systemic metabolic abnormalities, and previous diagnosis of epilepsy were excluded from this study. A total of 367 children were included in this study. We categorized these patients based on the type of CFS (seizure type A: ?- 2 seizures in 24 hours, seizure type B: focal seizure, seizure type C: seizure ?- 15 minutes ) and analyzed the correlation between seizure type and EEG, MRI findings. The Institutional Review Board approved this study. Results: There were a total of 367 patients: seizure type A- 175 patients (48%), seizure type B-121 patients (33%) and seizure type C-71 patients (19%). EEG was performed in 156/367 and MRI in 145/367 patients. EEG abnormalities were noted in 19/156 (12.2%) and MRI abnormalities were seen in 30/145 (20.7%). See graph # 1. Seizure type A: 65/175 had EEG's and 70/175 had MRI. Of these 7/65 (10.8%) EEGs were abnormal and 7/70 (10%) had abnormal MRI's of which 4/7 had focal abnormalities. Seizure type B: 47/121 had EEG's and 47/121 had MRI. Of these 6/47 (12.5%) EEGs were abnormal and 15/47 (31.9%) had abnormal MRI's of which 7/15 had focal abnormalities. Seizure type C: 44/71 had EEG's and 28/71 had MRI. Of these 6/44 (13.6%) EEG's were abnormal and 8/28 (28.6%) MRIs were abnormal, 5/8 of which showed focal abnormalities. Conclusions: 1.?- 2 seizures in 24 hours were the most common type of CFS presentation, followed by focal CFS and the least common was CF seizure ?- 15 minutes. 2. Patients with CFS lasting > 15 minutes were more likely to get an EEG (62%) compared to patients with the 2 other types of CFS (focal -38.8%) & (?- 2 seizures in 24 hours -37.1%) (p=0.04). 3. Brain MRI was performed more frequently in patients with CFS lasting > 15 minutes compared to other seizure types (p=0.29). 4. Brain MRI abnormalities were seen more frequently in focal CFS and prolonged CFS (32% and 28.6%) compared to ?- 2 seizures in 24 hours (10%) and focal MRI abnormalities were most frequent in prolonged CFS (17.8%) 5. Overall EEG abnormalities were similar in all 3 seizure types (10.8%, 12.8%, and 13.6%) (p= 0.89). Focal spikes and slowing was more common in focal CFS (~15%) compared to the other 2 types of CFS (11.3 % and 10.7%). See graph # 2. MRI should be considered for prolonged CFS and focal CFS as it may affect prognosis discussions and management decisions. EEG should be considered for focal CFS as focal abnormalities were higher in this group and may affect management. MRI and EEG may not be indicated for all CFS patients who have ?- 2 seizures in 24 hours. Other factors such as family history of epilepsy, neurologic exam and development should be considered before making decisions regarding investigations for these patients. Funding: None