Differential diagnosis of episodic symptoms.

Because nonepileptic disorders may cause episodic and paroxysmal symptoms that resemble epilepsy, these conditions and syndromes must be considered in the differential diagnosis or when antiepileptic drugs are ineffective. Gastroesophageal reflux usually presents as recurrent vomiting in infants and young children. A small subgroup of infants develop apnea and cyanosis accompanied by posturing of the limbs, deviation of the eyes, or opisthotonos, which leads to the incorrect diagnosis of epilepsy. Breathholding spells and pallid infantile syncope, common in infants and young children, may also be mistaken for epileptic attacks. The parasomnias, including pavor nocturnus and somnambulism, are frequently mistaken for epilepsy, since these nocturnal episodes are paroxysmal in nature, may be associated with automatic behavioral mannerisms, and tend to be recurrent. Migraine is especially difficult to differentiate from epilepsy because its manifestations, particularly in children, are so diverse. Other disorders that may superficially mimic epilepsy include transient ischemic attacks, syncope, and transient global amnesia.