A study on serum calcium and magnesium levels in seizures disorders in pediatric age

Introduction

Seizures are the most common neurologic disorder of childhood, occur in 4 to 10%, approximately and accounts for 1% of all emergency room visits.1, 2 The incidence is highest among the children below 3 years and decreases with increasing age.3, 4

Epileptic seizures can be induced in any normal human brain with a variety of different electrical or chemical stimuli. The ease and rapidity with which these seizures can occur, and the stereotyped nature of the seizures produced suggest that the normal brain, particularly the cerebrum contains within its fine anatomic and physiologic structure, a mechanism which is inherently unstable and which can be influenced in many different ways to produce a seizure. Thus many kinds of metabolic abnormalities and atomic lesions of brain are claimed to produce seizures, and conversely, there is no pathognomonic lesion of the epileptic brain.

The influence of infectious diseases on the serum minerals is clearly reported in the literature.5 Similarly children with seizures present frequently to emergency department also require a thorough laboratory work up, because elevated calcium(Ca) and magnesium (Mg) is found to have increasing roles in pathophysiology of epilepsy. Hypomagnesiemia and hypocalecimia cause hyper excitability of neurons which is associated with seizures in adults and children. Influence of dietary Mg deficiency in seizures is reported.6 However some other studies reported that there is no change in levels of serum Ca and Mg in seizure disorders. 7

With these it is very clear that there is controversy in serum Mg and Ca levels in seizures. Hence a study was undertaken to find the correlation between serum Ca and Mg levels and seizure disorders in pediatric age group.

Materials and Methods

It was a prospective case control time bound study, conducted in the department of paediatrics, Gandhi Medical College, Secunderabad. Study was conducted over a period of 1 year, March 2011 to 2012. Study protocol was approved by the institutional ethics committee. Informed written consent was taken from the parents of the participants.

Children of both gender, aged I month – 14 years with seizures were included in the study. Those aged > 14 years, who are on AED, with neurologic defects such as hemiplegia, mental retardation, developmental delay, with cutaneous syndromes such as tuberous sclerosis, neurofibraomatosis, VHL, sturge weber syndrome) and those who refused submit the consent were excluded.

During the study period, convenient sampling was considered. Total 80 samples considered. The participants were divided into test and control groups. All the study participants were included in the test group and non seizures children were grouped in control category.

Thorough clinical examination and detailed history was taken from all the study members. Investigations such as neuro imaging, EEG were conducted to find the etiology of seizures. Then venous blood samples were collected for the estimation of serum electrolyte levels, 24 hours after onset of seizures on admission. Blood samples were sent to laboratory for estimation of serum electrolytes by using ion selective electrode potentiometry. 5

Results

Among the 80 (100%) study members, 50 (62.5%) were test and 30 (37.5%) were included in control groups. Age wise, in the test group, 22% (11) were < 1 – 5 years age, 28% (14) in 6 – 10 years age and 50% (25) in 11 – 14 years age. Where as in control group, it was 33.3% (10) each in 1 – 5 years, 6 – 10 years and 11 – 14 years age, respectively (Table 1). The mean age was 8.6 and 7.8 years respectively in test and control groups.

In this report, 36% (18) were diagnosed to be idiopathic epilepsy, meningoencephalitis, neurocysticercosis in 14% (7) each, tuberculoma in 12% (6), hypoparathyroidism in 6% (3) and seizures in 18% (9) cases. Seizures were diagnosed to be due to gliosis, mesial temporal sclerosis, infarcts, hippocampal sclerosis, leighs disease (Table 2).

In the control group, Ca were ranged between 5.1 - 6 mg/dl and Mg levels were between 1.5 – 20 meq/l. Whereas in test group, Ca were ranged between 4.1 – 4.9 mg/dl and Mg levels were between 1.6 – 2.0 meq/l. Statistically there was significant difference between the serum electrolyte levels among the test and control groups, respectively (Table 3). The electrolyte levels were statistically significant among the children with and without epilepticus (Table 4).

Discussion

Epilepsy is one of the old maladies, serious neurological disorders reported in the Charakasamhita, 400 BC; it was called with a Sanskrit word means loss of consciousness.8, 9 However, the perception of epilepsy, a brain disorder begun in 18 century. Approximately 5 – 10% population have at least one seizure attack in the life, the incidence was more in early childhood. 10 More than 50% of seizures have their onset in childhood. 9

The incidence was 13% below 10 years age and 20% between 30 – 60 years age group. 11 In this study, the 50% of the children were below 10 years, the mean age was 8.6 years. The mean age was reported to be 9.43 years by in one of the north India reports by Pandey et al. 12 The investigators also reported that 10.05 years was the mean age in urban population 8.82 years for rural. However, the data were not analyzed in this category in this study.

Gender wise, in this study, the male female ratio was 1.5. The male female ratio was reported to be Tambe SHM et al. 10 Similar results were also reported by Holden et al and Powell et al. 13, 14 Holden et al. 13 studied 227 neonates of which 157 (56.77%) neonates were male and 120 (43.32%) neonates were female. Powell et al. studied total of 24 cases of which 17 (70.83%) were male neonates and 7 (29.16%) were females neonates. 14 But the cause for the male child predominance was not reported.

In this study, mean + SD values of serum Ca and Mg levels were 4.66 ± 0.94 mg/dl, 5.23 + 0.52 mg/dl and 1.81 ± 0.25 meq/l, 1.94 + 10.16 meq/l respectively in the test and control groups; statistically there was significant difference (Table 3). Ca levels were declared as 4.5 ± 0.08 mg/dl, 4.66 ± 0.04 mg/dl by Odapi et al., 15 2.38 ± 0.12 mg/dl, 2.48 ± 0.12 mg/dl by R Sinert et al., 16 respectively in the test and control groups. When Mg levels were considered, Horaciom et al. 17 reported 1.81 ± 0.2 meq/l, 2.08 ± 0.06 meq/l, 1.7 ± 0.22 meq/l, 2.1 ± 0.19 meq/l by S K gupta et al.,18 respectively in the test and control groups. Seizures were reported when the serum Ca levels fall below 2.4 mg/dl and when the Mg levels were considered below1.2 meq/l is the threat. 19 In addition, sodium levels are also another influencing factor. 20, 21 but in this study, sodium levels were not estimated, which is another limitation of this research.

In this study, Idiopathic was identified as predominant (36%) cause, followed by meningoencephalitis, neurocysticercosis, tuberculoma and hypoparathyroidism (Table 2). Similar findings were reported by R Sinert et al. 16 Vimelesh et al. mentioned that tuberculoma and tubercular meningitis were the common causes for this epilepsy in the pediatric age. 22 Supraorbital brain abscess was mentioned as common cause for epilepsy by Charles G et al. and meningoencephalitis by et al. 23

The mean Ca levels were 4.7+1.061 mg/dl and Mg level was 1.8+0.24 meq/l among the study subjects with the status of epilepticus; statistically there was no significant difference (Table 5). Similarly there was no significant difference between Ca and Mg levels among the study subjects without the status of epileptics (Table 5). There was fall in the serum Mg levels with the status of epilepticus. But this observation is not consistent with S K Gupta et al. 18 According to Uzma Jamil et al. report, serum Ca level was nearly half and Mg was nearly 2/5^th of previously diagnosed epileptics who were currently presented in status. 23

Conclusion

These we conclude that there was decrease in serum Ca and Mg levels among the children with seizures. However, there was no correlation between the levels of serum electrolytes and severity of seizures.

Conflict of Interest

The authors declare that they have no conflict of interest.

Source of Funding

None.