(NEW) Electrocardiographic Changes In Children With Idiopathic Epilepsy And Epilepsy Secondary To Structural Brain Lesions

Introduction

Many changes in autonomic functions is associated with epileptic seizures , which may contribute to immediate or soon after cardiovascular, pulmonary, gastrointestinal, cutaneous, and urinary  manifestations .^[1]

One of the most dangerous changes occurs due to epileptic seizures are cardiovascular changes, which may result in sudden unexpected death in epileptic patients. Moreover, seizure leads to disturbance in cardiac functions and  resulting in  syncopal events.^[2]

Notably generalized convulsive seizures, put  the cardiovascular system on strain, which may promote cardiac complications such as cardiac arrhythmias, cardiomyopathy, and myocardial infarction.^[3]

 In the context of neurological diseases, wide variety of changes in the electrocardiogram (ECG) are seen. Arrhythmias and repolari-zation changes are the two major categories of change  were noticed . ^[4]

It is likely that the increased tendency for life threatening arrhythmias in patients with acute neurological disease is a result of the repolarization change, which increases the vulnerable period during which an extrasystole would be likely to result in ventricular tachycardia and/or ventricular fibrillation.

Therefore, the essential and potentially most lethal features of the ECG, which are known to change in the context of neurological disease, are the ST segment and T wave, which reflect abnormalities in repolarization.^[4]

Subjects and methods

This was a case control study conducted on children recruited from Pediatric Inpatient Department of Minia University Hospital for Obstetrics & Gynecology and Pediatrics in the period from April 2022 to April 2023.

This studied included 60 epileptic children diagnose according to ILAE criteria. ^[5] They were divided into group I: included idiopathic epileptic children, group II: included epileptic children secondary to structural brain lesions and 30 healthy children as controls represented group III.

Epileptic children age between 1 year old to 12 years old and who do not have any cardiological diseases were included in this study.

Ethical approval

For any patient enrolled into the study, the purpose and design were explained to the parents in details. A written consent was obtained from parents of each patient. We avoided utilizing deceptive practices by obtaining parents’ informed   consents prior to participant enrollment, which gave participants the option to withdraw from the study at any time. The ethical committee of the faculty of Medicine, Minia University approved this study (Approval No.337:5/202).

All patients were subjected to:

Full History taking: including; (Age, Sex, Family history, Prenatal, natal, and postnatal history, history of seizures (onset, duration, frequency, and type of seizures), (Diagnosis of epilepsy type done according to international league against epilepsy (ILAE) 2017 classification), developmental milestones, medications taken).Clinical examination including; systemic examination, anthropo-metric measures: (weight, length, height, head circumference and BMI) and complete neurological examination.

• Laboratory investigations including:

       Liver function tests (ALT, AST and serum albumin), renal function tests (blood urea and serum creatinine) and complete blood count to exclude other system affection.

• Magnetic Resonance Imaging studies of the brain (Brain MRI) were done to differentiate between idiopathic epilepsy and epilepsy secondary due to structural brain lesions (SBL).

• Digital Electro-Encephalogram (EEG) for all patients in the study: Nihon Koden digital EEG machine was used; the EEG was carried out on 16 channels.

• Electrocardiogram (ECG);

      Inter-ictal 12-lead ECG in the first 24h after the seizures was performed for all patients.

Results

This study showed no significant difference among all studied groups (children with idiopathic epilepsy, epilepsy secondary due to structural brain lesions (SBL) and control group) as regarding their demographic data. (Table 1)

No significant difference between group I (idiopathic epilepsy) and group II (epilepsy secondary to SBL) regarding the frequency of seizure per year, type of epilepsy, duration of seizure, duration of postictal drowsiness, family history of convulsion, and EEG changes, while there is a significant higher frequency of fever associated with seizure in group I (idiopathic epilepsy) than group II (epilepsy secondary to SBL) (p value <0.0001). There is also a significant higher frequency of motor and mental developmental delay in group II than group I (p value <0.0001) for each of them. Moreover, there is a significant higher age of seizure onset in epileptic children secondary due to SBL than in group I idiopathic epilepsy children (p value <0.027). (Table 2) 

No significant differences in ECG rhythm, ST segment, T wave, and QRS complex among all studied groups. There is a significant higher heart rate (tachycardia regarding the cut point

for age) in idiopathic epilepsy children and children with epilepsy secondary to SBLthan controls (p value >0.001 & <0.0001) respectively. (Table 3)

There is no significant difference in liver function, renal function and Na, K, Ca results among all studied groups.

(Table 4) 

Discussion

This study showed that the age of onset of seizure in idiopathic epilepsy children was significantly younger than children with epilepsy secondary to SBL, while there was no significant difference between them regards frequency of seizures per year, type of epilepsy, duration of seizures, postictal durations or EEG changes (P value 0.027)

This was in agreement with Camfield &Cam-field and Falco-Walter who noticed that the incidence of idiopathic epilepsy is increased in the first year of life and declines to adult levels by the end of 10 years of age.^{[6] [7]}

Beghi stated that idiopathic epilepsy and epilepsy secondary to SBL can occur at any age and there is no specific age for them, as secondary epilepsy may occur due to structural brain lesions, intracranial hemorrhage, ischemic insult in the brain or congenital brain malformation and tumors which could happen at any age and this is against our results. ^[8]

In this study, there was no significant changes in ECG rhythm, ST segment, T wave and QRS complex among idiopathic epileptic children & epileptic children secondary to SBL and control group.

Similar  results were obtained from Ufongene, El Atrache who reported  no changes in ECG  in epileptic children  early during postictal period. ^[9]

While Gigli, Sala stated that there is a higher incidence of ECG abnormalities in epileptic patients close to the seizure time and the epileptic patients have more ECG abnormalities in comparison to their baseline ECG. ^[10] Also Chan, Dervan stated that   ECG changes were common in pediatric epileptic patients. Nonspecific ST segment and T-wave changes represented the most common alterations with

the prevalence of 19% and 30%, respectively, this is against our results. ^[11]

This study reported that heart rate increases significantly in group I (idiopathic epilepsy) & group II (epilepsy secondary to SBL) when compared to group III (controls) (P value <0.001 &,0.0001) respectively.

This  was in agreement with Moseley, Nickels, Chouchou, Bouet, Myers, Sivathamboo and Schomer, Baljak who reported that postictal tachycardia occurred in 61%  of the studied  epileptic patients and they emphasizes the role of tachycardia as the most frequent cardiac complication of seizures. ^{[12],[13],[14],[15]}

This study also found a significant positive correlation between heart rate (HR) and duration of seizure in group I (idiopathic epilepsy) & group II (epilepsy secondary to SB) (R=0.49, P=0.006 and R=0.69, P<0.0001) respectively.

Ali, Bubolz and Brewster, Marzec reported that patients who had status epilepticus (who suffered from seizure which last for 5 minutes or more) are associated with higher incidence of having postictal ECG abnormalities that reflect altered ventricular depolarization–repolarization in children without prior seizure history and in children with epilepsy, this was in agreement with our results. ^[16],[17]

Nass, Motloch and Ibrahim, Megahed reported that  patients who had suffered prolonged seizure duration or continuous epileptic EEG discharges  propagated to the central autonomic network, altering or disrupting the normal autonomic regulation of essential cardiac functions and causing sub-endocardial isch-emia which  lead to increase cardiac enzymes level and ECG changes and cause increase in heart rate, this is in agreement with our results. ^[18],[19]