Tests and diagnosis

By Mayo Clinic Staff

Some children experience episodes that resemble absence seizures, but aren't seizures. Such episodes usually can be interrupted by calling the child's name or by touching his or her shoulder. True absence seizures, on the other hand, can't be interrupted by voice or touch. Absence seizures may occur in the middle of a child's conversation or physical activity.

Your doctor will ask for a detailed description of the seizures. Blood tests can help rule out other potential causes of seizures, such as a chemical imbalance or the presence of toxic substances. Other tests may include:

  • Electroencephalography (EEG). This painless procedure measures waves of electrical activity in the brain. Brain waves are transmitted to the EEG machine via small electrodes attached to the scalp with paste or an elastic cap. Your child may be asked to hyperventilate or look at flickering lights, an attempt to provoke a seizure. During a seizure, the pattern on the EEG is different from the normal pattern.
  • Brain scans. Tests such as magnetic resonance imaging (MRI) can produce detailed images of the brain, which can help rule out other types of problems, such as a stroke or a brain tumor. This test is not painful, but your child will need to hold still for long periods of time. Talk with your doctor about the possible use of sedation, especially for young children.
Jun. 23, 2011