A seizure occurs due to abnormal electrical firing in the brain and is characterised by a change in behaviour, uncontrolled jerking movements and may be accompanied by loss of consciousness. Most seizures last for a few seconds to two minutes. Any seizure that lasts for more than five minutes is a medical emergency. Seizures in full-term babies within 28 days after birth or before 44 weeks of gestation age in preterm babies is known as neonatal seizure and affects about 2 per 1000 live births in term infants and up to 20 per 1000 live births in premature infants.Its prevalence in India is estimated to be about 0.7% in full-term babies and 1.1% in preterm babies.
Neonatal seizures are difficult to diagnose and left untreated it can lead to permanent disability or death. In India, mortality associated with neonatal seizures is reported to be about 15%, but varies depending on cause of seizures. Neonatal seizures can develop due to poor oxygen supply in the brain which is known as hypoxic-ischemic encephalopathy (HIE) and in severe cases can lead to death in 50% of the babies suffering from the condition. It can also lead to long time disabilities such as brain damage, cerebral palsy, learning disabilities, hearing or vision loss later in life. Neonatal seizures due to severe bleeding in the brain also have a high mortality rate. Seizures due to birth defects are associated with a high risk of brain damage and learning disabilities later in life. About 20% to 30% of children with neonatal seizures develop epilepsy later in life.
CAUSES AND RISK FACTORS
Evidence suggests that prematurity, birth after the due date, low or high birth weight, family history of seizures or epilepsy, maternal health conditions such as diabetes, hypertension and obesity or heavy smoking are associated with a high risk of seizures in neonates.
The other causes of seizure in an infant may include lack of oxygen before or during birth, infections, stroke, bleeding in the brain, blood clots in the brain, brain defects, certain birth conditions, low blood sugar levels, electrolyte imbalance, etc.
RECOGNISING SIGNS AND SYMPTOMS
Neonatal seizures in most cases do not become generalised, affect only one part of the brain and their manifestations are very difficult to distinguish from normal activities such as chewing or bicycling movements in babies. However, some of the common signs and symptoms that parents can look for include sudden jerking or stiffening of the leg and hand muscles, unusual bicycling movements of the legs, change in facial expression and heart rate, repetitive facial or eye movements, the baby stops breathing for a few seconds, failure to respond to familiar sounds, staring, etc.
These signs and symptoms may be commonly confused with the Moro reflex in babies in which they get startled suddenly such as a loud noise or bright light or shivering movements when the child has a fever. Unlike seizures, these movements can be stopped by restraint.
Seeking paediatrician advice is recommended to establish an exact diagnosis.
Several medical examinations including an Electroencephalography (EEG), laboratory testing such as pulse oximeter, blood tests, urine tests, etc, cranial imaging with the help of CT scan or MRI, coupled with detailed family history and physical examination can help diagnose the condition accurately in a new-born child. A CT scan helps to detect brain malformations and bleeding inside the brain. An MRI can help to understand these changes more accurately.
Sometimes the doctor may suggest video monitoring of the child to understand the signs and symptoms more clearly. In children with recurrent seizures or unknown causes, a genetic test may also be considered.
Newborn seizures are managed in a specialised hospital setting known as the neonatal intensive care unit (NICU). Management primarily focuses on treating the underlying cause to stop recurrent episodes and thus treatment varies in each case. The medical team will look for the underlying cause such as infection or low blood sugar levels and treat the baby accordingly. In many cases, the doctor may administer anti-epileptic drugs or other medications to stop repeated seizure episodes.
The writer is a Consultant – Pediatrics, PICU, and Neonatology, Manipal Hospital Whitefield.