Syndromes

Classifying epilepsy by seizure type alone leaves out other important information about the patient and the episodes themselves. Classifying into syndromes takes a number of characteristics into account, including the type of seizure; typical EEG recordings; clinical features such as behavior during the seizure; the expected course of the disorder; precipitating features; expected response to treatment, and genetic factors.

Epileptic syndromes can be either idiopathic (of unknown cause) or symptomatic of underlying brain damage or disease. In general, idiopathic forms have a better prognosis in terms of both seizure control and eventual remission than do symptomatic forms. Epileptic syndromes include seizure syndromes in newborns; hypothalamic hamartomas; febrile convulsions; West syndrome (infantile spasms); Lennox-Gastaut syndrome; childhood absence epilepsy; juvenile myoclonic epilepsy; Benign Rolandic epilepsy; Landau-Kleffner syndrome; Rasmussen's encephalitis (syndrome); progressive myoclonic epilepsy; temporal lobe epilepsy, and frontal lobe epilepsy. Types of epilepsy that appear in infancy range from benign to severe, although persistent epilepsy that begins during the first year of life tends to remain severe, sometimes throughout life. Some authorities would not include febrile (fever-generated) seizures in this list. Many consider them to be non-epileptic seizures because they cease to be a problem as the child grows older.

Epileptic syndromes in newborns include benign neonatal convulsions; familial benign neonatal convulsions; early myoclonic encephalopathy; and severe idiopathic status epilepticus. Usually, seizures in newborn babies are caused by identifiable metabolic or infectious conditions, many of which are associated with complications around the time of birth. In general, outcome following neonatal seizures depends more on the cause of the seizure than on the specific type. Newborns whose seizures are due to transient metabolic causes, who have normal clinical and EEG examinations, and who develop normally usually do not have epilepsy and do not require prolonged antiepileptic therapy.

Newborns whose seizures are due to disorders that affect brain structure (encephalopathies) are at risk for later epilepsy. This is especially true for newborns with brain malformations or hypoxic-ischemic disease that causes permanent brain damage and produces cerebral palsy.

Seizure-like phenomena. A variety of medical conditions may produce sudden episodes which have some similarities to epileptic seizures. Migraine and transient ischemic attacks (TIA's), for example, may produce visual disturbances; hyperventilation produces tingling, light-headedness and occasionally loss of consciousness, as does syncope (fainting).

In children, breath holding spells may lead to blueing of the lips and some jerking; tics likewise produce jerking; sleepwalking and other sleep disturbances may mimic seizure symptoms, while episodic dyscontrol syndrome produces rage attacks that may be erroneously identified as epileptic seizures.

Non-epileptic seizures. Non-epileptic seizures (also referred to as pseudoseizures, psychogenic or cryptogenic seizures) are episodic, paroxysmal events not related to abnormal electrical activity in the brain. Click here to read more about non-epileptic seizures.