Article updated and reviewed by Peter B. Kang, MD, Assistant in Neurology, Children's Hospital Boston, and Instructor in Neurology, Harvard Medical School, Boston, MA. Editorial review provided by VeriMed Healthcare Network on April 18, 2005.
Seizures are characterized by abnormal electrical activity in the brain, usually causing changes in behavior such as rhythmic movements or confusion. An individual with epilepsy is someone who has recurrent spontaneous seizures, that is, seizures that are not associated with triggers such as fevers or head trauma.
Please see the “Epilepsy (Seizure Disorders)” section for basic information about seizure types, emergency management, and medications.
There are a number of seizure syndromes that affect children, not all of which meet the criteria for epilepsy. Three common seizure syndromes are febrile seizures, Rolandic epilepsy, and absence epilepsy.
Febrile seizures are seizures that are triggered by fevers, and typically occur in children from the age of six months to five years. Simple febrile seizure are ones in which the seizure is brief (up to several minutes in duration), generalized (stiffening and shaking of all limbs), limited to one seizure for the duration of the illness, and occur in children who are developmentally normal and have no known chronic neurological disorders. Simple febrile seizures, barring injury during the seizures themselves, are generally benign, with no significant long term consequences for neurological development known to date and only a slightly increased risk for epilepsy in the long term. Simple febrile seizures are not generally regarded as a form of epilepsy since the seizures are not spontaneous. If there are features that mark the seizures as being complex (or “atypical”) rather than simple, there may be a higher risk of epilepsy and serious long term consequences for neurological development. Many children with complex febrile seizures still do fairly well. Simple febrile seizures often do not require specialized testing such as electroencephalography (EEG, an electrical brainwave test like an EKG) or an MRI scan, but complex febrile seizures may require such an evaluation. If a child has seizures both with and without fever, the child meets the criteria for epilepsy. An important concern to keep in mind, especially with an infant who has a seizure with fever, is that such a seizure may be the first sign of meningitis, so any child with a first time febrile seizure should be evaluated at the nearest hospital emergency department. Depending on the circumstances, subsequent seizures may require evaluation also, especially if the seizure is prolonged or if the child does not recover afterwards in the same manner as in previous events. Febrile seizures sometimes run in families.
Rolandic epilepsy is a common form of childhood epilepsy that is characterized by partial seizures. This disorder begins between infancy and puberty. The most common seizure type is the simple partial seizure, characterized by abnormal motor activity of a specific part of the body (for example, one arm or one leg). The face may be affected, leading to difficulty speaking. These seizures generally occur at night. Sometimes one of these partial seizures will generalize (spread to the rest of the brain) and develop into a generalized tonic-clonic (“grand mal”) seizure. This form of epilepsy can be diagnosed based on the description of the events and a characteristic pattern of abnormalities (centrotemporal spikes) on EEG. There may be variants with slightly different forms of seizures or slightly different abnormalities on EEG. The seizures are usually easy to control with medication, and by adolescence they typically resolve and the medication can gradually be weaned off. This is a benign form of childhood epilepsy, and affected children generally have normal neurological development.
Absence (“petit mal”) epilepsy typically begins in the first decade of life (after infancy). The seizures are mild generalized events characterized primarily by brief staring spells that last a few seconds, followed by a resumption of the interrupted activity. To others, including teachers and parents, they may appear only as a brief pause in activity. There are no convulsions (stiffening or shaking), but occasionally there may be other mild manifestations such as lip smacking or drooling. These seizures may happen dozens of times per day. Some children with absence epilepsy are thought by their parents or teachers to be daydreamers or to have attention deficit hyperactivity disorder because the spells interrupt schoolwork and make them appear distracted and unfocused. The description of the spells may be subtle, and are often not sufficient for diagnosis. Two aids to diagnosis include hyperventilation and an EEG. Hyperventilation is known to trigger these seizures, so a neurologist may ask the child to blow at a fan or other object during the office visit for several minutes. If the child stares off while hyperventilating, the neurologist may call out a color or other word, and then when the child stops staring, ask him or her what word was spoken. If the staring spell was a true seizure, the child should not have any recollection of hearing that word. In some cases, the child has the episodes so frequently that this test can be done without hyperventilation. The EEG is very accurate in diagnosing this form of epilepsy, since the seizures occur so frequently. A very characteristic electrical discharge appears on the EEG, and is usually correlated with a staring spell. Absence seizures respond very well to medication, and can make an enormous difference in the child’s school performance and learning. Usually, these seizures resolve spontaneously by adolescence and the child can gradually be weaned from the medication. In some cases, the seizures persist longer, and may develop into other forms of epilepsy in adolescence and adulthood. Neurological development is variable; many affected children do well, but some have subtle difficulties that persist into adulthood.
There are many other seizure syndromes that affect children. A pediatrician and/or a pediatric neurologist should be consulted whenever a seizure disorder is suspected.