What do seizures in newborns look like?
Seizures in newborns (babies in the first month of life) are different from seizures that occur in older children and adults. The seizures often are fragmentary because the infant's brain is still developing and is unable to make the coordinated responses seen in a typical generalized tonic-clonic seizure.
- The baby may have jerking or stiffening of a leg or an arm that can alternate from side to side.
- Or the whole upper body may suddenly jerk forward. Or both legs may jerk up toward the belly with the knees bent.
- The baby's facial expression, breathing, and heart rate may change.
- Impairment of responsiveness (which is critical in defining many types of seizures) is difficult to assess in newborns. Parents may suspect that responsiveness is impaired when their voices are unable to attract the newborn's attention.
Even experts have difficulty in recognizing seizures in newborns. Normal babies have many sudden, brief jerks, grimaces, stares, and mouth movements that might suggest epilepsy in an older child or adult. A diagnosis of epilepsy in an infant is more likely if...
- The behavioral changes are not typical of children of the same age. Some parents videotape the suspected behavior at home for viewing by the doctor.
- Repeated episodes are identical in their behavioral features and duration.
- The episodes occur while the child is both awake and asleep.
- The episodes are not brought on by changes in posture or activity, or can not be stopped by gentle manipulation of the arm or leg.
What behaviors are easily mistaken for seizures?
The Moro reflex in babies is a perfectly normal response that can be easily mistaken for a seizure. When a baby is startled, such as by momentary removal of support of its head, a loud noise, or a bright light, it suddenly will stiffen its back; its arms and legs will extend outward from the body; and its fingers will fan out. The Moro reflex is present in its full form until age 3 months and in an incomplete form until age 5 months.
Another example of normal behavior in infants that may be confused with seizures is jitters. Jitters are shivering movements or tremors and are not epileptic seizures. They are similar to the shivering that occurs with fever in older children and adults.
Does the EEG help diagnose seizures in newborns?
The electroencephalogram (EEG), which is usually so helpful in defining seizures, is more difficult to interpret in newborns. Although the normal and abnormal patterns of brain electrical activity in newborns are becoming more clearly defined, areas of uncertainty still exist, and only specially trained pediatric neurologists can expertly interpret newborn EEG patterns.
What does 'benign familial neonatal convulsions' mean?
Newborns with a rare genetic disorder, benign familial neonatal convulsions, begin having frequent brief seizures in the first few days of life. The disorder usually is inherited by an autosomal dominant gene (that is, one parent also had the disorder). It may also result from a spontaneous mutation in the child's DNA. The seizures usually stop by 6 to 9 months of age.