A seizure is caused by sudden, abnormal, and excessive electrical activity in the brain. Neonatal seizures occur during the neonatal period for a full-term infant which is the first 28 days of life. Most occur in the first one to two days to the first week of a baby’s life. Premature or low birth weight babies are more likely to suffer neonatal seizures than full-term babies.
Neonatal seizures or neonatal convulsions are epileptic fits occurring from birth to the end of the neonatal period in a child. The neonatal period is the most vulnerable of all periods of life for developing seizures, particularly in the first 1–2 days to the first week from birth. They may be short-lived events lasting for a few days only. However, they often signify serious malfunction of or damage to the immature brain and constitute a neurological emergency demanding urgent diagnosis and management.
- Lack of oxygen before or during birth due to placental abruption (premature detachment of the placenta from the uterus), difficult or prolonged labor, or compression of the umbilical cord.
- Infection acquired before or after birth, such as bacterial meningitis, viral encephalitis, toxoplasmosis, syphilis, or rubella.
- Stroke before or after birth
- Blood clot in the brain
- Bleeding in the brain
- Brain birth defects
- Blood sugar or electrolyte imbalances
- Metabolic disorders such as maple syrup urine disease, pyridoxine dependency or phenylketonuria (PKU).
- Drug withdrawal, which may affect babies born to mothers addicted to barbiturates, alcohol, heroin, cocaine or methadone
Neonatal seizures can be difficult to diagnose because the seizure may be short and subtle. In addition, symptoms of neonatal seizures may mimic normal movements and behaviors seen in healthy babies.
Symptoms depend on the type of seizure
- Tonic or myoclonic.
Symptoms of neonatal seizures in all types include:
- Random or roving eye movements, eyelid blinking or fluttering, eyes rolling up, eye-opening, staring
- Sucking, smacking, chewing, and protruding tongue
- Unusual bicycling or pedaling movements of the legs
- Thrashing or struggling movements
- Long pauses in breathing (apnea)
- Rhythmic jerking movements that may involve the muscles of the face, tongue, arms, legs or other regions of the body
- Stiffening or tightening of the muscles
- Turning the head or eyes to one side, or bending or stretching one or more arms or legs
- Quick, single jerking motions, involving one arm or leg or the whole body.
- Electroencephalogram (EEG), EEG records the electrical activity of the brain, and abnormalities on an EEG test (measured between seizures) can indicate a risk for seizures.
- Magnetic resonance imaging (MRI)
- Computed tomography (CT) scan
Once a seizure has been diagnosed, treatment directed at the underlying disease needs to be initiated. Anticonvulsant therapy includes the following:
- Phenobarbital is the drug of the first choice to treat neonatal seizures. It is relatively effective, the side effects are well appreciated, and the pharmacokinetics are reasonably well understood for the term and preterm infants. A loading dose of phenobarbital (20 mg/kg) will achieve a therapeutic level of approximately 20 µg/ml, which is not affected by birth weight or gestational age. The intravenous route is preferred because of the more rapid onset of action and more reproducible effects on blood levels. The maintenance dose of phenobarbital is lower in the first week of life (3.5 mg/kg/day) and increases to 5 mg/kg/day with increasing postnatal age.
- Dilantin is often the second drug of choice to be added when seizures are not controlled by phenobarbital alone. A loading dose of 20 mg/kg intravenously will achieve therapeutic blood levels (approximately 15 µg/ml) and a maintenance dose is 5 mg/kg/day.
- Lorazepam is useful for infants with “uncontrolled” seizures in spite of therapy with phenobarbital and Dilantin. The usual dose is 0.05 – 0.1 mg/kg per dose. Due to the possibility of respiratory depression (especially with phenobarbital on board), the safest use of these drugs is when ventilatory support has been initiated.
COMPLICATION OF SEIZURES
Complications from prolonged or frequent neonatal seizures include:
- Developmental delay
- Cerebral palsy with possible contractures
- Epilepsy later in life
- Feeding issues or swallowing issues.
- This is usually related to the underlying cause of the seizures.
PREVENTION OF SEIZURES
Prevention depends on the causes of the seizure.
- Avoid sepsis and metabolic derangements
- Improve delivery methods and oxygenation can help to reduce neonatal seizures.
- Early diagnosis, detection, and treatment of seizures and subclinical seizures can decrease long-term sequelae.
- If neonatal seizures are related to inborn errors of metabolism, specific diets may help prevent seizures.
- Genetic counseling for neonates with disorders such as benign familial neonatal seizures will help to prevent seizure.
- Pyridoxine deficiency/dependent seizures and metabolic disorders with a known mutation can help some couples avoid these disorders in future pregnancies.
WHAT TO DO IF YOUR CHILD HAS A SEIZURE:
If someone is nearby, ask them to call for a doctor. If no one is with you, follow the steps below and then call the doctor:
- Gently place your child on the floor or ground, and remove any nearby objects.
- Lay your child on his or her side to prevent choking on saliva (spit).
- If your child vomits, clear out the mouth gently with your finger.
- Loosen any clothing around the head or neck.
- Make sure your child is breathing OK.
- Don’t try to prevent your child from shaking, this will not stop the seizure and may make your child more uncomfortable.
- Don’t put anything in your child’s mouth. Your child will not swallow his or her tongue, and forcing teeth apart could cause injuries or block the airway.
- Don’t give your child anything to eat or drink, and don’t give any medicine pills or liquid by mouth until your child is completely awake and alert.
- Try to keep track of how long the seizure lasts.
- Your child may be sleepy or may take a while to get back to normal after the seizure. Stay with your child until he or she is awake and aware, and let your child rest after the seizure.