What should be done for a patient with a history of seizures who experienced an aura before their last seizure?

Management of a Patient with Seizure History Who Experienced an Aura Before Their Last Seizure

The presence of an aura before a seizure indicates a focal (partial) onset and helps localize the epileptogenic zone, but does not change acute management—the patient should still be evaluated according to standard first seizure protocols, with discharge appropriate if they have returned to baseline and have no high-risk features. 1, 2

Understanding the Clinical Significance of the Aura

The aura represents the initial manifestation of a focal seizure with preserved awareness, occurring when abnormal neuronal discharge activates functional cortex before consciousness is lost. 3, 4 This has important diagnostic and prognostic implications:

• Localization value: The specific type of aura helps identify the seizure focus—epigastric, gustatory, and olfactory auras suggest mesial temporal origin (particularly with hippocampal sclerosis), while visual/oculosensory auras suggest occipital involvement, and somatosensory auras indicate parietal cortex activation. 5, 6, 4

• Seizure classification: The presence of an aura definitively classifies this as a focal onset seizure (even if it secondarily generalized), which influences long-term treatment decisions and prognosis. 3, 4

• Risk stratification: Focal seizures may indicate underlying structural pathology requiring neuroimaging, though the aura itself does not mandate emergent imaging unless other high-risk features are present. 1, 2

Immediate Emergency Department Management

Critical Initial Actions

• Check serum glucose and sodium immediately, as these are the only laboratory abnormalities that consistently alter acute management. 1, 2

• Obtain pregnancy test if patient is of childbearing age, as this significantly impacts medication choices if treatment is initiated. 1

• Perform neurological examination to assess if patient has returned to baseline—persistent focal deficits (Todd's paralysis) may indicate need for admission. 5, 1

Neuroimaging Decision Algorithm

Perform emergent CT head without contrast if ANY of the following high-risk features are present: 1, 2

• Age >40 years
• Recent head trauma
• Persistent altered mental status
• New focal neurological deficits
• Fever or persistent headache
• History of malignancy or immunocompromised state
• Anticoagulation use
• Focal seizure onset (which the aura confirms)

For low-risk patients (young, returned to baseline, normal neurologic exam, reliable follow-up), deferred outpatient MRI is acceptable, as MRI is the preferred imaging modality for detecting epileptogenic lesions. 1, 2

Important caveat: Approximately 22% of patients with normal neurological examinations still have abnormal CT findings, and 23% of patients with new-onset seizures have acute stroke or tumor on CT. 1 The presence of an aura (indicating focal onset) strengthens the indication for neuroimaging, though timing can be deferred if other high-risk features are absent. 2

Disposition and Recurrence Risk

Discharge Criteria

The patient can be safely discharged if ALL of the following are met: 1, 2

• Returned to clinical baseline neurological status
• Normal neurological examination
• No persistent altered mental status
• No abnormal investigation results requiring inpatient management
• Reliable follow-up arrangements established

Seizure Recurrence Timeline

• The mean time to first seizure recurrence is 121 minutes (median 90 minutes), with 85% of early recurrences occurring within 6 hours of ED presentation. 1, 2, 7

• The overall 24-hour recurrence rate is 19% in all seizure patients, decreasing to 9% when alcohol-related events and focal CT lesions are excluded. 1, 2

• Nonalcoholic patients with new-onset seizures have the lowest recurrence rate (9.4%), while alcoholic patients with seizure history have the highest (25.2%). 2

Antiepileptic Drug Treatment Decision

Patients with a first unprovoked seizure who have returned to baseline can be discharged without initiating antiepileptic medication, as treatment does not improve long-term outcomes despite reducing short-term recurrence risk. 1

However, the American Academy of Neurology recommends that treatment be initiated after a second seizure, as the strategy of waiting until a second seizure is considered appropriate for first unprovoked seizures. 1

Key consideration: The number needed to treat to prevent a single seizure recurrence within the first 2 years is approximately 14 patients, exposing patients to medication adverse effects without proven mortality or morbidity benefit. 1

If treatment is initiated (typically after second seizure or in high-risk situations), levetiracetam is effective for focal seizures with doses of 1000-3000 mg/day in divided doses, showing 17-23% reduction in seizure frequency over placebo. 8

Special Considerations for Aura-Specific Management

Distinguishing Aura from Stroke Mimics

The European Society of Cardiology guidelines help differentiate epileptic aura from other conditions: 5

• Rising abdominal sensation with unpleasant smell or taste that is specific to the patient and recurring suggests epileptic aura rather than vasovagal syncope. 5

• Déjà vu/jamais vu is pro-seizure and supports epileptic origin. 5

• Migrainous aura may be confused with seizure aura, but migraine aura typically has gradual progression (visual symptoms spreading over minutes), whereas epileptic aura is more abrupt. 5

Long-Term Implications

Important counseling point: In patients with hippocampal sclerosis who undergo successful epilepsy surgery, 18.9% have persistent auras despite being seizure-free, whereas only 2.6% of patients with structural lesions have persistent auras post-surgery. 6 This suggests anatomical dissociation between seizure generation and aura production in mesial temporal epilepsy. 6

Common Pitfalls to Avoid

• Do not assume all auras are benign—late-onset migraine-like headaches with prolonged visual aura may indicate occipital arteriovenous malformation and require immediate brain imaging. 9

• Do not miss stroke mimics—approximately 28-48% of suspected first seizures have alternative diagnoses including syncope, nonepileptic seizures, and panic attacks. 2, 7

• Do not fail to establish accurate time of onset—creative questioning about phone call timestamps or TV programming times may allow treatment of patients initially identified as "onset time unknown." 5

• Do not overlook the need for EEG—while surface EEG frequently fails to detect changes during isolated auras, abnormal EEG findings predict increased risk of seizure recurrence and should be obtained in outpatient follow-up. 2, 3