USE OF LUMBAR PUNCTURE FOR FIRST EPISODE OF FEBRILE SEIZURE AMONG CHILDREN 6 MONTHS TO 18 MONTHS OF AGE : A CROSS SECTIONAL STUDY

Introduc on Febrile seizure accounts for the majority cases of the pediatric seizure. Fever with seizure can be either due to febrile seizure or underlying serious infec on as meningi s. As seizure may be the only manifesta on of meningi s it is important to rule out meningi s in children presen ng with fever and seizure.


Objec ve
The objec ve of this study was to determine the incidence of meningi s among children aged 6 to 18 months presen ng with first episode of febrile seizure.

Methodology
A prospec ve observa onal study was conducted among 94 children with first episode of febrile seizure presen ng to the emergency and observa on wards of Kan Childrens' Hospital and subjected to lumbar puncture (LP) as per the American Academy of Pediatrics (AAP) recommenda ons.The propor on of children with meningi s and no meningi s among the study popula on was determined, clinical characteris cs were compared among these groups and the incidence of meningi s in simple febrile seizure and complex febrile seizure was calculated.The collected data was analysed using SPSS.

Results
Twenty (21.3%) cases were diagnosed with meningi s among 94 children enrolled in our study.Meningi s was detected in 38.1% of the cases of complex febrile seizure and 7.7% of cases of simple febrile seizure.In the age group 6 to 12 months, 11 (17.4%) had meningi s while in 12 to 18 months of age, 9 (29%) were detected with meningi s.Meningi s was 7.38 mes more likely in cases presen ng with complex febrile seizure than simple febrile seizure (OR=7.58;95% CI 2.24-24.4;p<0.001).Regarding the clinical characteris cs, vomi ng, fever of more than 48 hours dura on prior to onset of seizure, impaired consciousness and complex features of seizure were found to be significantly associated with meningi s in our study.

Conclusion
The probability of meningi s among children aged 6 to 18 months presen ng with first episode of febrile seizure episode is high.In febrile convulsing children less than 18 months of age, meningi s should be considered even in the absence of signs of meningeal irrita on .

INTRODUCTION
Febrile seizure is the most common form of childhood seizure.Febrile seizure is seizure that occurs between 6 months to 5 years of age with a temperature of 38 degrees cen grade or higher that is not the result of CNS infec on or metabolic imbalance that occur in the absence of history 1 of prior afebrile seizure.Febrile seizure can be classified as either simple or complex.A simple febrile seizure is primarily generalized, usually tonic-clonic a ack associated with fever, las ng for a maximum of 15 minutes and not recurrent within a 24 hours period.Complex febrile seizure is more prolonged (>15 min), is focal and recurs within 24 hours.
Febrile seizure accounts for 1-5% of emergency department 2,3 visits.The precise annual incidence of febrile seizure worldwide is not known.The incidence varies among different regions.In western Europe and USA the incidence is reported to be 2-5% whereas it is between 5-10% in India, 8.8% in Japan, 14% in Guam, 0.5-5% in China and 6.6% in [4][5][6] Nepal.
In May 1996, recommenda ons were laid down by AAP regarding evalua on of children with the first episode of febrile seizure who present within 12 hours a er the seizure.This guideline strongly recommended LP in children less than 1 year of age and considered in children between 12 to 18 months for diagnosing meningi s via 7 cerebrospinal fluid (CSF) analysis.These recommenda ons were based on the knowledge that seizure is a common presen ng symptom of bacterial meningi s and clinical assessment of children at this age for signs of meningi s 8 can be difficult.However, in 2011 AAP updated their guideline recommending LP in any child whose history or examina on suggests the presence of meningi s or intracranial infec on.The guideline states that in any infant between 6 and 12 months of age LP is an op on when the child is considered deficient in Haemophilus influenza type b (Hib) or Streptococcus pneumonia immuniza on or when immuniza on status cannot be determined and it is an op on in child who is pretreated with an bio cs as an bio c treatment can mask signs and symptoms of meningi s.⁷ Meningi s is a major cause of childhood morbidity and mortality.Early detec on and treatment are important to reduce the chances of adverse neurological outcome and death associated with it.The probability of bacterial meningi s in children with fever and seizure varies from 9 0.6% to 6.7%.
Although there exist data regarding the yield of lumbar puncture among children with first episode of febrile seizure, the studies reflects a variable prevalence of meningi s.However only a few data exist regarding our country targe ng children 6 to 18 months of age.Thus this study aims to evaluate the importance of lumbar puncture as this group has been iden fied as clinically difficult to assess for bacterial meningi s and meningeal signs are not always present.

METHODOLOGY
This was a hospital based prospec ve observa onal study which was conducted at the emergency and observa on wards of Kan Childrens' Hospital from November 2013 ll October 2014.The inclusion criteria included all children 6 to 18 months of age with the first episode of febrile seizure who presented to the emergency and observa on ward within 12 hours a er the seizure.Those diagnosed with previous history of seizure disorder, chronic illness, trauma, neurosurgical interven on and cri cally ill children were excluded from the study.A er ini al stabilisa on of the children, detailed history was taken and examina on done.Children were considered febrile if their axillary temperature 0 exceeded 100.4 F. Inves ga ons were sent to determine the focus of infec on.A er informed and wri en consent LP was done according to the AAP guidelines.The children were then observed for at least 12 hours.The propor on of children with meningi s and no meningi s among the study popula on was determined based on LP reports and the incidence of meningi s in simple febrile seizure and complex febrile seizure was calculated.Meningi s was 3 considered in a child if he/she had CSF count > 5cells/mm , rd protein>40mg/dl and sugar<2/3 of blood sugar or gram stain posi ve for bacteria and/or posi ve CSF culture.Seizure characteris cs as type, dura on, character, interval between fever and seizure, number of seizure episodes and pos ctal drowsiness, the presence of meningeal signs and the presen ng symptoms and signs were compared between the meningi s and no meningi s group.The causes a ributable to fever in febrile seizure were also iden fied and final diagnosis assigned a er complete history, examina on and inves ga on.Data entry and analysis were done by using SPSS version 16.Categorical data was analyzed by chi-square test.P value of <0.05 was considered significant.

RESULT
During the study period of one year, 94 children who met the inclusion criteria were enrolled in the study.The age group was categorised into two groups: 6 to 12 months and 12 to 18 months as per the AAP prac ce parameters.The study group 6 to 12 months included 63 (67.1%) children whereas, 12 to 18 months group included 31 (33.9%)children.Almost two third of the cases (67%) of febrile seizure were below 12 months of age.There was male predominance in the study popula on with the male:female ra o of 1.8:1.Of the total cases, majority of the children (55%) presented with simple febrile seizure.Among the pa ents with febrile seizure, almost one fi h (21.3%) had meningi s (Figure 1).Meningi s was more commonly detected in children with complex febrile seizure than simple febrile seizure (Table 1).Significant associa on was observed in the occurrence of meningi s and the type of febrile seizure (p<0.001).Among 20 cases of meningi s, there was a total of 11 (54.5%)cases in the age group of 6 to 12 months and 9 ( 45.5%) cases in the age group of 12 to 18 months so the higher incidence was seen in children less than 12 months(Figure 2).Regarding clinical characteris cs sta s cal corela on was found between dura on of fever of more than 48 hours before the presenta on of seizure and meningi s(p=0.007).Vomi ng (p=0.009) and impaired consciousness (p=0.031) were found to be significantly associated with meningi s.The mean temperature o recorded in the meningi s group was 102.2+0.96F S.D. o whereas it was 101.5+1.01 .F S.D. which was sta s cally significant (p=0.004).The most common cause of fever in febrile seizure was URTI (27.7%) followed by pneumonia (18%) and bronchioli s (16%) (Table 2).The incidence of meningi s was compara vely higher in our study than others.It may be because about a large propor on i.e. 45.7% of the cases in our study presented with complex febrile seizure which poses a greater risk of meningi s than simple febrile seizure.Meningi s was detected in 38.1% of the cases with complex febrile seizure compared to 7.7% of the cases with simple febrile seizure (p<0.001).Significant difference is observed in the incidence of meningi s among children with simple and complex febrile seizure which is comparable to other studies.A study done by Tavasoli et al in Ali Asghar Children Hospital, Iran showed meningi s to be associated more with complex febrile seizure than 16 simple febrile seizure ( 84.2% Vs 15.8%, p<0.001).Similarly in other studies conducted by Casasoprana et al and Batra et al, the incidence of meningi s was higher in complex febrile seizure than simple febrile seizure (13% Vs 0% and 15,17 44.81% Vs 0.86% respec vely).
The mean age of presenta on of meningi s was 11.1+ 4.25 months S.D. In our study younger age is found to be associated with higher risk of meningi s.The majority of children with meningi s were less than 12 months.In 6 to 12 months age group, 63 cases (67.1%) had meningi s as compared to 31 cases (32.1%) in 12 to 18 months age group.Significant difference is observed in the incidence of meningi s among the children less than and over 12 We have found in our study that febrile convulsing children with meningi s have propor onately higher grade fever than children with no meningi s.Similar observa ons were made by Ghotbi et al and Singh et al who considered high grade fever as independent predictor of meningi s among 14,18 children with first febrile convulsion.
Regarding clinical characteris cs sta s cal corela on was found between dura on of fever of more than 48 hours before the onset of seizureand meningi s (p=0.007).Meningi s was detected in 10 cases (50%) who presented with fever of more than 48 hours dura on.Similar finding was observed in study done by Al-Eissa et al in which meningi s most commonly occurred with fever of this 19 dura on.In our study, pa ents with meningi s had significantly greater frequency of impaired consciousness which was sta s cally significant (p=0.0001).It was comparable with the studies conducted by Casasoprana et al, Tavasoli et al and Al-Eissa Y et al. and in which impaired consciousness was considered to be a significant risk factor 15,16,19 for meningi s.
Regarding the e ology of the febrile illness leading to the seizure, URTI (27.6%) followed by pneumonia (18%) and bronchioli s (11.7%) were the common causes of fever in our study.URTI was the commonest cause of fever in children 12,17,20 in this study which was similar to other studies.

CONCLUSION
In this prospec ve observa onal study, the incidence of meningi s was found to be high (21.3%)among children aged 6 to 18 months presen ng with their first episode of febrile seizure.Meningi s was more commonly associated with complex febrile seizure than simple febrile seizure.Children with complex febrile seizure were 7.38 mes more likely to have meningi s in comparison of simple febrile seizure.Though it is difficult to diagnose younger children with meningi s clinically as children less than 18 months usually lack signs of meningeal irrita on, certain characteris cs as vomi ng, complex features of seizure, delayed seizure i.e. more than 48 hours of onset of seizure and impaired consciousness were found to be significantly associated with meningi s.

RECOMMENDATIONS
In the view of high probability of meningi s among children aged 6 to 18 months presen ng with first episode of febrile seizure, lumbar puncture needs to be considered.In febrile convulsing children less than 18 months meningi s should be considered even in the absence of signs of meningeal irrita on.

LIMITATION
An important limita on to our study is the small number of pa ents.The other limita on include shorter period of study.Our study reflects data from one center and may not be represent that of other centers across the country so as, given that our study was conducted in one study center with a small sample size, a mul center trial would be necessary to determine the incidence of meningi s in pa ents aged 6 to 18 months.

Figure 1 :
Figure 1: Propor on of study popula on with meningi s (n=94) 10,11,17 months of age in other studies too.The mean temperature recorded in the meningi s group o was 102.2+0.96F S.D and no meningi s group was o 101+1.01F S.D. which is sta s cally significant (p = 0.004).

Table 1 :
Associa on between type of seizure and meningi s

Figure 2 :
Distribu on of cases of meningi s according to age and sex (n=20)

Table 2 :
Causes of fever in the study popula on Among 94 children enrolled in our study, 20 (21.3%) children had meningi s showing that almost one fi h of the children presen ng with febrile seizure had meningi s.Similar high incidence of meningi s was detected among children between 6 to 18 months in study done by Shrestha et al in Nepal and Owusu-Oforiet al in Ghana in which the 10,11 incidence of meningi s was 20.3% and 10.2% respec vely.But it is much higher as compared to study done by Ehsanipour et al at Hazrat Rasoul Hospital, Iran in which meningi s was *some pa ents had more than one diagnoses DISCUSSION 12 reported in 3.6% of the cases.Similar low incidence of meningi s (3.8%) was observed in a cross sec onal study conducted by Watemberg et al in Israel (3.8%), Ghotbi et al 13-15 (4.7%) and Casasoprana et al(1.9%).