Neonatal seizure

A neonatal seizure is a seizure in a baby younger than age 4-weeks that is identifiable by an electrical recording of the brain. It is an occurrence of abnormal, paroxysmal, and persistent ictal rhythm with an amplitude of 2 microvolts in the electroencephalogram, detected in infants younger than 4 weeks. These may be manifested in form of stiffening or jerking of limbs or trunk. Sometimes random eye movements, cycling movements of legs, tonic eyeball movements, and lip-smacking movements may be observed. Alteration in heart rate, blood pressure, respiration, salivation, pupillary dilation, and other associated paroxysmal changes in the autonomic nervous system of infants may be caused due to these seizures. Often these changes are observed along with the observance of other clinical symptoms. A neonatal seizure may or may not be epileptic. Some of them may be provoked by stimulation or suppressed by restraining them. According to the International League against Epilepsy (ILAE), seizures are basically abnormally excessive or synchronous neuronal activity in the brain that is manifested as signs or symptoms. This definition, however, excludes the electrographic-only seizures that comprise 40-60% of that found in critically ill neonates. As per the classification system by the American Clinical Neurophysiology Society, seizures can be classified into electroclinical, clinical only, and electrographic-only seizures. Neonatal seizures have been classified into various types depending on various parameters. The earlier classification system, focused more on differentiating these neonatal seizures from those experienced in adult children. Neonates were found to experience either tonic or clonic seizures. They did not experience tonic-clonic seizures. If seizures were found to be focal, they were further classified into unifocal or multifocal. Seizures in the neonatal population can be mainly categorized into acute symptomatic seizures and neonatal epilepsy that is related to genetic or structural factors.