Consultation with the Specialist: Management of Status Epilepticus in Children

The definition of status epilepticus (SE) is a simple, prolonged seizure or recurrent seizures associated with impaired consciousness for 30 minutes or longer. There are two types of SE: convulsive and nonconvulsive. The latter consists of prolonged absence or complex partial seizures.SE occurs most frequently in patients younger than 1 year of age and those between 60 and 80 years. Determining the underlying cause of SE is of utmost importance and is directed by the clinical presentation. The differential diagnosis is similar in all age groups, although the frequencies change in the various diagnostic categories. Table 1 delineates some of the leading causes of SE in various age groups.The differential diagnosis in any age group should include both systemic and central nervous system (CNS)infections; trauma; hypoxia; CNS malformations; ischemic events, including stroke or hemorrhage; and toxic or metabolic causes, including electrolyte imbalance, alcohol use, illicit drug use, and inborn errors of metabolism. External and internal antiepileptic drug withdrawal also is a significant factor.The incidence of SE due to infection and congenital anomalies is higher in the pediatric age group. If a child is younger than 3 years of age,infection, hypoxia, or metabolic disturbances are the most likely causes. In the child older than 3 years, idiopathic epilepsy, congenital anomalies, or chronic encephalopathies are the more likely precipitants. Although usually benign, febrile seizures can progress to SE.Neonatal SE is challenging to diagnose and treat because seizures in neonates are usually subtle and not dramatic in appearance. Clinical manifestations include rhythmic eye movements, rowing or pedaling motions of the legs, tonic posture, or less commonly focal or multifocal generalized tonic, clonic, or tonic-clonic seizures. It often is difficult to correlate clinical seizures with electrocerebral epileptiform activity on electroencephalography (EEG). The decision to treat needs to be based on the underlying etiology of the seizures, background and ictal activity of the EEG, and consideration of the consequences of chronic antiepileptic drug administration.SE is associated with a poorer prognosis in adults than in children. Average mortality rates in one study were 25% for adults versus 2.5% in children. Alcohol and drug abuse account for a large percentage of cases of SE.Table 2 lists a classification scheme for SE. Convulsive,either generalized or partial, is the most easily recognizable form of SE. Nonconvulsive often is difficult to identify and to differentiate from confusional migraine and psychiatric fugue states. Cascino reported that 25%of persons experiencing SE have absence or complex partial SE.Important differential diagnoses in patients who have nonconvulsive SE (absence or complex partial), depending in part upon their age, include confusional states or unresponsiveness associated with transient ischemic attacks,transient global amnesia, stroke, or migraine. Toxic and metabolic causes should be sought early in the evaluation. One must always consider psychiatric disorders, such as various forms of psychosis, fugue states, and