European Journal of Cardiovascular Medicine

Febrile seizure recur 30% of children after the first episode, 50% after two or more episodes and 50% of infants less than one year old. Half of recurrences occur within six months following the first episode, 3/4^th of recurrences within 1 year and 90% occur within 2 years of first episode [1]. There is no affirmation that febrile seizures or febrile status epilepticus can lead to cerebral palsy, neurologic damage, mental retardation, decrease in IQ and learning problems. Approximately 1/3^rd of children with a first episode of febrile seizure will have an episode of recurrence; 10% will have 3 or more episodes of febrile seizures. The most cardinal risk factors are family history of FS and onset of first febrile seizure at less than 12 months of age. Two other definitive risk factors for recurrence of FS are height of the temperature and the time interval between the onset of fever and the episode of seizure. In general, if the temperature is very high, the chance of recurrence is low. In one study, those with a temperature of 101°F had 42% risk for recurrence at 1 year, 29% risk for those with a temperature of 103°F, and only 12% risk for those with a temperature of 105°F. Second, if the extent of recognized fever is short, the chance of recurrence is high. The recurrence risk at 1 year is 46% for those with a FS within one hour of recognized onset of fever, compared with 25% risk for those having fever lasting for 1 to 24 hours, and 15% risk for those having >24 hours of recognized fever prior to the event of febrile seizure [2, 3].

A recurrent febrile seizure is more likely to be prolonged if the first episode was a prolonged episode. The correlation between the overall risk of recurrent febrile seizure and a family history of unprovoked seizures appears to be uncertain. A large study in Rochester, Minnesota, found out that there exists no difference in risk for recurrence of FS in a child with a family history of epilepsy (25%) and those without such family history (23%) [4].

Data were collected from patients visiting causality and admitted under the Department of Pediatrics, with informed consent fitting the inclusion and exclusion criteria

METHODS OF DATA COLLECTION

Patients coming to casualty of Department of Paediatrics with history of fever preceeding convulsions has considered for the purpose of the study after initial management, informed consent fitting the inclusion and exclusion criteria will be taken and patients consenting for the study was taken up. Data were gathered orally with appropriate history taking and from investigations done.

SAMPLE SIZE

A sample size of 250 Children aged 6 months to 60 months with both simple and complex febrile seizures admitted in Hospital.

INCLUSION CRITERIA

Children aged 6 months to 5 years with both simple and complex febrile seizures, who are admitted Hospital, and whose parents had given written informed consent.

EXCLUSION CRITERIA

• Children with seizure suspected to have central nervous system infection on first day itself and also diagnosed following LP.
• Children with seizure due to hypocalcemia and hypomagnesia.
• Children with at least one episode of a febrile seizures
• Seizure following trauma, drug, or toxin intake.
• Seizure in children with CSOM.

EVALUATION AND INVESTIGATIONS

All the patients are personally subjected to detailed history regarding name, age, sex, occupation, socioeconomic status, general physical examination, systemic examination.

INVESTIGATIONS DONE

1.  
2. Random blood sugar.
3. Renal function test.
4. Serum electrolytes.
5. Brain imaging and EEG (when and as required).
6. CSF analysis (when and as required).

After getting informed written consent from the parents or care givers, Children of both sexes from 6 months to 60 months of age having simple or complex febrile seizure were admitted and investigated regarding various risk factors for recurrence of febrile seizure. Other etiologies causing fever with seizure were excluded by history, clinical examination and relevant investigations. Children with recurrent febrile seizures were reviewed with their old records. All children either first episode or recurrence were followed up fortnightly in specialty OPD during the study period. Missed children were followed up whenever they had come to OPD.

Among 100 children with recurrent FS, 55 children (55%) had experienced initial febrile seizure when they were less than one year old. But, other 30 in number (30%) developed their first FS after their first birth day. Most of the children with recurrent FS had experienced their initial febrile seizure prior to their first birth day. Hence, it is one of the most important risk factor for recurrent FS.

Table 1: Association with age while developing first FS

Table 2: Bivariate analysis

Age less than 1 year while developing febrile seizure had a statistically significant association with recurrence of febrile seizure (p = 0.0001).

Most of the children (60.60%) are male among 100 children with recurrent febrile seizure. (Other 39.39%) are female children. So, male children are more prone for developing recurrent febrile seizure.

Table 3: Sex distribution in recurrent FS

Male children had a significant association with recurrence of febrile seizure statistically with the p value of 0.006.

Out of 100 patients with recurrent febrile seizures, 24 patients (84.84%) developed seizures within 24 hours of onset of fever. Rest of the 8 patients (24.24%) developed after 24 hours of onset of fever. Hence, duration of fever less than 24 hours from the onset of fever has a strong association with the development of recurrent febrile seizure.

Table 4: Association of fever duration with recurrent FS

Table 5: Bivariate analysis

This bivariate analysis had shown that the duration of fever less than 24 hours prior to the seizure was a significant risk factor for recurrence of febrile seizure (p = 0.01)

Out of 100 children with recurrent FS, 33 children (57.70%) had experienced more than one episode of recurrence and other 47 children (42.3%) had only one recurrent FS. Hence, number of recurrent episode itself increases the frequency of recurrent FS. So, it is also an important risk factor for recurrent FS.

Table 6: Number of recurrent febrile seizure

Table 7: Bivariate analysis

Multiple recurrent febrile seizure had itself increased the recurrence significantly (p = 0.004)

Among children with recurrent FS (100), 20 children (60.60%) did not have family history of febrile seizure either in 1° or 2° relatives. 13 children (39.39 %) had significant family history of FS. Hence, family history of FS either in 1° or 2° relatives does not affect the recurrence of febrile seizure.

Table 8: Association with family history of FS

Table 9: Bivariate analysis

Family history of recurrent febrile seizure did not have significant association with recurrent febrile seizure in the child (p = 0.3).

Younger age at first seizure, short duration of fever before the onset of first febrile seizure, lower temperature at onset, and family history of febrile seizures are risk factors of recurrence of febrile seizures in children. Out of 100 children with recurrent FS, 33 children (57.70%) had experienced more than one episode of recurrence and other 47 children (42.3%) had only one recurrent FS. Hence, number of recurrent episode itself increases the frequency of recurrent FS. So, it is also an important risk factor for recurrent FS. Among children with recurrent FS (100), 20 children (60.60%) did not have family history of febrile seizure either in 1° or 2° relatives. 13 children (39.39 %) had significant family history of FS. Hence, family history of FS either in 1° or 2° relatives does not affect the recurrence of febrile seizure. According to WHO guideline, anemia is defined as hemoglobin level is less than 11 g/dl. Out of 100 children with FS, 62 children (62%) had Hb < 11 g/dl. Other 38 children (38%) had Hb > 11g/dl. Hence, anemia may be a risk factor for development of febrile seizure. It may be a risk factor for development of recurrent FS. Because, among 100 children with recurrent FS, anemia was seen in 62 children (57.7%). Rest of them are not anemic (38%) and had Hb > 11 g/dl. But, this is statistically significant (p = 0.006).

In the study of Ausi Indriani et al., [5], among children with recurrent FS, 72 % were males and 28% were females. In contrast, the study of Anil Raj Ojha et al. [6] found that 54% of female children had experienced recurrent FS. But, there was not a statistical significance (p =0.584).

Hence, male gender is one of the most significant risk factor for recurrence of FS. In this study, 73.9 % of children with recurrence had seizure within 24 hours of fever and rest of them (26.1%), after 24 hours. Similar results were obtained in the following studies; in the study of Berg AT et al. [7], they had enlightened that 67% of children had recurrent FS within 24 hours of fever and 13%, after24 hours (p<0.001). In a study by Nadirah Rasyid Ridha et al. [8], revealed that the children having FS within 12 hours of fever were 4.96 times more prone for developing recurrent FS Ausi Indriani et al. [5] found that 46 % of children with recurrence had seizure within 24 hours of fever and 31%, within 24 to 48 hours of fever in their study. Anil Raj Ojha et al. [6], in their study, found that 60 % children had developed recurrent FS within 12 hours of fever (p =0.026. Hence, duration of fever less than 24 hours is a significant risk factor for FS recurrence.

In this study, among children with recurrent FS, only 45.9% had positive family history (1˚ relative). But, in the meta analysis by Offringa et al. [9], 43% children with recurrent FS had positive family history (1˚ relative) and 32%), without family history. Berg et al. [6] found that 36% of children with positive family history had recurrence at one year and 20%, without family history. In another study by berg et al. shown that patients with positive family history (1˚ relative) were 1.62 times more prone for having recurrent FS. Nadirah Rasyid Ridha et al. [5], in their study, found that patients with positive family history of FS were 6 times more commonly affected with recurrence. In contrast to the above studies, Van stuijvenberg et al. [10] found that positive family history (1˚ relative) had a relative risk of 0.8 with recurrent FS. Ausi Indriani et al., in their study revealed that family history were positive in only 28% of patients with recurrent FS and negative in 57 % of patients. Hence, family history of febrile seizure does not affect the risk of recurrence of febrile seizure.

The present study concludes that, the younger age at onset of first seizure, lower temperature during the seizure, brief duration between onset of fever and initial seizure were more significantly associated with recurrence of febrile seizures among children. These risk factors should be kept in mind by the physician, while dealing with a child suffering from febrile seizures.

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