Clinical Approach to Diagnosis

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When seeing a child with possible epilepsy, the questions posed in the following subsections must be answered (Fig 1).

Is It a Seizure?

Determining whether a particular spell is truly an epileptic seizure versus a nonepileptic paroxysmal event can be challenging. Studies of children referred with a “first seizure” have shown that approximately one-quarter did not truly have an epileptic event. (10)(11) Table 1 contains descriptions of spells and lists the typical ages affected for common nonepileptic events that may be mistaken for seizures.

Seizures that arise from a focal brain region are typically preceded by a characteristic aura, which provides helpful localizing information because it usually reflects the area where the seizure arises. However, an aura is not present for seizures that are generalized in onset. Convulsive seizures and seizures that impair awareness are typically followed by a postictal state, in which the patient is sleepy and confused. Postictally, patients may also have transient focal weakness (Todd paresis) or language difficulties, depending on which area of the brain was involved in the seizure.

If This Is a Seizure, Is It Provoked?

Certain factors, most importantly high fever, may provoke seizures in children with otherwise healthy brains. Febrile seizures are common, affecting 3% to 5% of all children, and in most cases do not evolve into epilepsy. (12) A seizure would be considered to be febrile if it occurred in a child 6 months through 5 years of age without a history of epilepsy, in association with a fever (temperature >100.9°F [>38.3°C]), without evidence of an intracranial infection. Febrile seizures are considered complex if they are focal, prolonged (>10–15 minutes), or occur more than once in a 24-hour period. Febrile seizures lacking any complex features are considered simple febrile seizures.

Other provoking factors may include intracranial infection, electrolyte disturbances, hypoglycemia, and traumatic brain injury. Most cases of provoked seizures are not considered to be epilepsy, which is defined as either 2 or more unprovoked seizures occurring more than 24 hours apart or 1 unprovoked or reflex seizure with a high probability of recurrence. However, in some types of epilepsy, specific triggers may induce certain seizure types (such as photosensitive seizures in juvenile myoclonic epilepsy).

If This Is an Unprovoked Seizure, What Type of Seizure Is It?

Epilepsy classification provides a framework for diagnosis. Epilepsy in children comprises a diverse group of etiologies and syndromes. The primary goal of classification is to improve clinical epilepsy care by increasing the likelihood of finding a precise diagnosis in a more cost-effective manner with fewer investigations for the child and to identify the optimal therapy. Accurate classification is also important for epidemiologic reasons.

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