ASSESSMENT OF IONIZED CALCIUM STATUS IN FEBRILE SEIZURES

Epilepsy is one of the most common disorders of the brain[1]. In normal lifespan at least one person in every ten is having epileptic seizure, out of which third will develop epilepsy. Approximately 50 million people are suffering from epilepsy worldwide. According to a World Health Organization (WHO), epilepsy shares 1% of the global burden of disease, which is equivalent to breast cancer in women and lung cancer in men [2].


INTRODUCTION
Epilepsy is one of the most common disorders of the brain [1]. In normal lifespan at least one person in every ten is having epileptic seizure, out of which third will develop epilepsy. Approximately 50 million people are suffering from epilepsy worldwide. According to a World Health Organization (WHO), epilepsy shares 1% of the global burden of disease, which is equivalent to breast cancer in women and lung cancer in men [2].
The terms convulsive disorder, seizure disorder and cerebral seizures are used synonymously with epilepsy. They all refer to recurrent paroxysmal episodes of brain dysfunction manifested by stereotyped alterations in behavior [1].
A sudden change in the behavioral activity or dynamic with in limited time is called convulsion and results from the abnormal electrical activity of the brain [3]. Children are more susceptible to develop convulsion and one of the most common forms of convulsion in Correspondence: Dr. Niranjan Singh, Assistant Professor, Department of Biochemistry, Varun Arjun Medical College, Shahjahanpur, U.P. India. E-mail: niranjandugtal@gmail.com children are febrile seizures which occur in 2-5% of children aged between 6 months and 5 years [4,5]. According to American Academy of Pediatrics (AAP), febrile seizures occur in the absence of central nervous system infection, metabolic disorders and in absence of a history of prior afebrile seizures [6]. Usually good prognosis is seen in febrile seizure; however, but increase in it's recurrence increases the risk of epilepsy in the future, they are considered as serious conditions [7]. Etiology of febrile seizures is yet to be determined precisely. Some of the conditions involved in the etiology of febrile seizures include the family history of febrile seizures and alcohol and cigarette consumption by the mother during pregnancy [8,9]. Prematurity, complications during childbirth and recent vaccination are among other risk factors of febrile seizures [10]. Inadequately evolved electrical system of the brain is responsible for febrile seizure as it is unable to struggle against the stress of rise in body temperature [11].
A common biochemical abnormality causing seizures is hypocalcaemia, which may manifest as muscle cramps, tetany, seizures and paraesthesia [12]. During any acute febrile disease, disturbances in water and electrolytes occur frequently. It has been suggested that change in serum calcium might enhance the susceptibility to seizures.

ABSTRACT
Introduction: Epilepsy is one of the most common disorders of the brain. One of every ten people will have at least one epileptic seizure during a normal lifespan, and a third of these will develop epilepsy. In children the most common forms of convulsion are febrile seizures. Water electrolyte imbalance occurs during acute febrile illness and hypocalcaemia is one of them. Hypocalcaemia is also present in cases of seizures. To find out significance of calcium levels in cases of seizures this study was conducted. Aims: To assess the level of ionized calcium in cases of febrile seizure. Methods: This Case -Control study was conducted on fifty cases of febrile seizures and fifty age, weight matched controls and calcium deficiency determined in both groups. The serum ionized calcium levels were estimated by ion selective electrode method using Na, K, Ca analyzer. Results: Mean ionized calcium level was 4.62±0.26mg/ dl and 4.88±0.27 mg/dl in study and control groups respectively and this difference was found statistically extremely significant (p<0.001). Conclusion: The findings suggest that a considerable percentage of children having febrile seizures are suffering from low level of calcium.  Grouping: Study group: 50 were cases of febrile convulsions.

Control group: 50 patients suffering from a febrile illness without seizures
Methodology: Demographic data, seizure details, nature of febrile illness, complete developmental history, and family history of epilepsy /febrile seizures was recorded. The serum ionized calcium levels were estimated by ion selective electrode method using Na, K, Ca analyzer.
Statistical analysis: Data was collected from eligible patients on a pre-structured pre-tested Proforma. For data analysis statistical software SPSS-20 version was used and data were analyzed with the help of proportions, measures of central tendency and appropriate statistical test.

RESULTS
Mean age was 2.16±1.08 years and 2.12±0.82 years in study and control group respectively and this difference was found statistically insignificant (p>0.05).
In present study, male predominance over females in both study and control groups, where total 70% and 64% patients were males in study and control groups respectively. On applying chi square test, the gender difference was found statistically insignificant (p>0.05).

Table 1. Distribution of cases according to Ionized Calcium (mg/dl) level in both groups
According to above table, in study group, 12 (24%) patients had abnormal (<4.4 mg/dl) range of ionized calcium level while in control group no patient had abnormal ionized calcium level.
Mean ionized calcium level was 4.62±0.26mg/dl and 4.88±0.27 mg/dl in study and control groups respectively and this difference was found statistically highly significant (p<0.001).

DISCUSSION
Convulsions or seizures are one of the important pediatric health problems in developing and developed countries and febrile seizures are the most common seizure disorder in childhood, affecting 2% to 5% of children between the ages of 6 and 60 months1. It is generally believed that FS is an age-dependent response of the immature brain to fever. This postulation is supported by the fact that most (80-85%) febrile seizures occur between 6 months and 3 years of age, with the peak incidence at 18 months. Studies based on animal models suggest that there is enhanced neuronal excitability during the normal brain maturation but the exact mechanism is still unclear [2].
In our study Mean ionized calcium level was 4.62±0.26mg/dl and 4.88±0.27 mg/dl in study and control groups respectively and this difference was found statistically highly significant (p<0.001).
In a study by Akbayramset al [13] where 48 children with febrile seizures were compared with age matched Our observation is also similar to studies by Chiarelli F et al. where Serum levels of sodium and calcium were significantly lower in children with FS. [14] There was no association between low Serum calcium and FS in studies by N. Rutter et al and Sayedzadeh S A et al. [15,16]

CONCLUSION
The findings suggest that a considerable percentage of children having febrile seizures are suffer from calcium deficiency and gender have insignificant role.