Specially trained doctors called pediatric neurologists try to identify the cause of seizures in newborns and infants. Commonly recognized causes of epilepsy before the age of 1 year include:

• Newborn illnesses (lack of oxygen, infection, hemorrhage, etc.)
• Abnormal brain development in the womb
• Genetic disorders
• Encephalitis (an infection of the brain)
• Meningitis (an infection of the membranes covering the brain)
• Febrile illness related seizures (febrile seizures)

Depending on the baby's medical history and examination results, the doctor may order a variety of tests or procedures to look for:

• Structural abnormalities in the brain, using magnetic resonance imaging (MRI) of the head with a special epilepsy protocol
• Abnormal background or electrical activity in the brain, using an EEG
• Chemical disorders or metabolic problems, using a variety of blood or urine tests
• Genetic disorders, using chromosomal studies
• Evidence of infection or metabolic disorders, or chemical disorders using a spinal tap (lumbar puncture)

The best test to look for abnormalities in the structure of the brain is MRI. If an infant's MRI scan looks normal during the first few months of life, the doctor is likely to repeat it later because some abnormalities that were not visible earlier may show up around 1 year of age.

The lumbar puncture, which is done to obtain a sample of cerebrospinal fluid, is safe and not very painful. The baby's worst crying usually comes when the doctor cleans the skin with a cool antiseptic solution. An anesthetic cream can be used to anesthetize the skin. Intravenous sedation is sometimes used.

In many cases no cause can be found. Brain injuries causing seizures may be impossible to pinpoint, especially injuries occurring in the womb or those associated with only microscopic damage. For example, seizure disorders in infancy may result from a viral infection in the mother during pregnancy that is undetectable with our current tests—though nearly all pregnant women who have mild viral infections have perfectly healthy babies.

Once in a great while, seizures in newborns and infants are caused by a deficiency of vitamin B6 (pyridoxine). It is important to recognize the deficiency because it is a very treatable cause of seizures. The diagnosis can be established by seeing whether the seizures improve when vitamin B6 is given by mouth, or by recording the EEG while injecting vitamin B6. An improvement in the EEG patterns indicates a vitamin B6 deficiency.

Topic Editor:James W. Wheless, M.D.
Last Reviewed:10/5/06