History and exam

Key diagnostic factors

common

focal neurologic deficits

Any focal deficits on exam may be evidence of a structural lesion resulting in symptomatic epilepsy.

focal neurologic symptoms (before or after seizure)

A description of specific and stereotyped neurologic symptoms either before or after a seizure can provide information about the type of epilepsy.

premonitory sensation or experience (fear, epigastric sensation, déjà vu, jamais vu)

A premonitory sensation or sequence of sensations more likely indicates focal-onset epilepsy, most often associated with temporal lobe origin.

Patients commonly have difficulty describing their aura.

temporary hemiparesis

A postictal paralysis or weakness on one side of the body is suggestive of focal-onset epilepsy, and generally indicates that the seizure focus is contralateral to the side of the deficit.

temporary aphasia

A postictal aphasia can also be seen after focal-onset seizures that involve language centers in the dominant hemisphere.

fever, nuchal rigidity, altered mental status

Seen in patients with seizure caused by central nervous system infection.

Other diagnostic factors

uncommon

neurocutaneous findings of neurologic disease

Some physical signs (neurocutaneous findings) may suggest an underlying neurologic disease that is associated with seizures. For instance, the presence of ash-leaf spots, shagreen patches, facial angiofibromas, and/or periungual fibromas are often indicative of tuberous sclerosis. Café au lait spots, axillary freckling, and/or fibromas are suggestive of neurofibromatosis.

Risk factors

strong

family history (extended or immediate) of generalized-onset epilepsy

For generalized tonic-clonic seizures due to generalized-onset epilepsies, a positive family history is strongly linked with the development of seizures. This is likely due to transmission of mutations to genes coding for a variety of ion channels and/or receptors involved in neural signaling.[12][13]​​​​

previous central nervous system (CNS) infection

Any major CNS illness (e.g., encephalitis, meningitis, neurocysticercosis) increases the risk of seizures. These illnesses are a major cause of epilepsy in low- and middle-income countries.[10][17]​​

head trauma

Any head trauma that results in prolonged loss of consciousness or is penetrating increases the risk of seizures later in life.[10][18]

CNS lesion

CNS lesions such as tumors and vascular malformations are associated with an increased risk of seizures.[19][20]

stroke

Stroke is the most common preventable cause of epilepsy among adults in high-income countries.[10]

prenatal or perinatal brain insult

Prenatal or perinatal brain insults are a primary cause of epilepsy in low- and middle-income countries in particular.[10]

intellectual disability

The prevalence of epilepsy is higher in people with intellectual disability than in the general population.[21]

HIV

Patients with HIV have a greater prevalence and incidence of seizures and epilepsy than the general population, and mortality rates are also higher.[22]

prior seizure events or suspected seizure events

In some cases, prior seizure events may have been misdiagnosed; thus, it is imperative to inquire about any potential seizures in the past.

weak

history of substance use

The use of alcohol or certain illicit substances can increase the risk of provoked or unprovoked seizure events. Cocaine, amphetamines, heroin, phencyclidine, and gamma-hydroxybutyric acid have been implicated.[23]

preterm birth

Children born preterm have an increased risk of developing epilepsy later in life, likely due to the increased incidence of periventricular hemorrhage.​​[24]​​[25]

multiple or complicated febrile seizures

Patients with recurrent or atypical febrile seizures (such as duration longer than 15 minutes and/or focality) may be at increased risk of generalized tonic-clonic seizure later in life.​​[26]​​[27]

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