This was a retrospective hospital-based study conducted in the Department of Pediatrics, Manipal Teaching Hospital, Pokhara. During period of July 2007 to July 2011 a total of 6975 children in the age group 6 months to 15 years were admitted in the Pediatric Department. Among these, 551 children (12.7%) were admitted with presenting complain of seizure and included in the study. Children with seizures onset after hospitalization were excluded.
The following information was obtained from the medical records of each patient: age (range from 6 months to 15 years), sex, type of seizure, associated symptoms (fever, cough, rhinorrhea, vomiting, diarrhea and headache), family history of seizure or epilepsy, developmental history, laboratory test results (white blood count, C-reactive protein, serum electrolytes, blood sugar and cerebrospinal fluid (CSF) analysis, neuroimaging; CT scan head or cranial magnetic resonance imaging (MRI),electroencephalography (EEG) findings, duration of hospital stay, final diagnosis. Final outcome was recorded in four categories; discharged after recovery, left against medical advice (LAMA), mortality and referral to other institutions were also recorded.
Patients were divided into two groups based on whether the seizure was with or without fever: Group 1 comprised patients with temperature recorded greater than or equal to 38°C, and Group 2 comprised patients with temperature less than 38°C. Seizure type classification, including generalized tonic-clonic (GTC), absence, myoclonic, partial and other seizures types was based on the Commission on Epidemiology and Prognosis, 1993 International League Against Epilepsy . Status epileptics was defined as, “a single epileptic seizure of more than 30 minutes or a series of epileptic seizures during which function is not regained between ictal events in a period more than 30 minutes long”. Febrile seizure was defined by the 1993 International League Against Epilepsy as, “an epileptic seizure occurring in childhood after 1 month of age, associated with febrile illness not caused by an infection of the central nervous system (CNS), without previous neonatal seizure or previous unprovoked seizure, and not meeting criteria for other acute symptomatic seizure”. In addition, febrile seizures were classified as simple febrile seizures or complex febrile seizures. A simple febrile seizure lasts less than 15 minutes, is initially generalized in nature, and occurs once during a 24-hour period. In contrast, a complex febrile seizure lasts more than 15 minutes, has focal features at any time, or recurs within a 24-hour period .
Other etiologies including meningitis and encephalitis were diagnosed on the basis of recorded clinical and laboratory investigation and verified with standard reference . Furthermore, patients were divided into three age groups: age group (6 months − 5 years), age group (6–10 years) and age group (11–15 years).Variables including age, sex, type of seizure, associated symptoms, family history of seizure or epilepsy, developmental history, laboratory test results, neuroimaging examinations, EEG findings, duration of hospital stay, diagnosis and final outcome were compared between febrile and afebrile group. These variables were also compared among children of different age groups.
Ethical committee approval
Preceding the study, approval for the study was obtained from the institutional research ethical committee of Manipal College of Medical Sciences.
Sample size calculation
By conducting a pilot study of 100 children with seizures it is estimated that for 95% confidence interval and, significance level α = 5%, P = 54%, Q = 46%, allowable error = 10%, required sample size was 327. P = percentage of children admitted with seizure and fever .
Descriptive statistics and testing of hypothesis were used for the analysis. The data was analyzed using Statistical Package for the Social Sciences (SPSS) for Windows Version 16.0 (SPSS Inc; Chicago, IL, USA). The Chi-square test was used to examine the association between different variables and strength of the relationship with logistic regression. Odds ratios (OR) and their 95% confidence intervals (95% CI) were calculated. P < 0.05 was considered as statistically significant [20, 21].