What is the appropriate acute and long‑term management of a patient presenting with a seizure?

Acute and Long-Term Management of Seizures

For a patient presenting with a first unprovoked seizure who has returned to baseline, do not initiate antiepileptic drugs in the emergency department; discharge home with outpatient neurology follow-up and arrange an outpatient EEG and MRI. 1, 2

Immediate Stabilization

• Assess airway, breathing, and circulation first; obtain a bedside finger-stick glucose immediately to exclude hypoglycemia as a reversible cause. 2
• If the seizure is ongoing (≥5 minutes), administer IV lorazepam 4 mg slowly (2 mg/min) as first-line therapy; have airway equipment and ventilatory support immediately available. 2, 3
• For refractory seizures after benzodiazepine, give phenytoin/fosphenytoin, valproate (30 mg/kg), or levetiracetam as second-line agents. 2

Laboratory Evaluation

• Obtain serum glucose and sodium in every patient—these are the only two laboratory tests that consistently alter acute ED management. 2
• Order a pregnancy test (urine or serum β-hCG) in all women of childbearing age, as pregnancy influences both diagnostic evaluation and antiepileptic drug selection. 2
• Reserve additional metabolic panels (calcium, magnesium, complete blood count) for patients with specific clinical clues such as vomiting, diarrhea, dehydration, known renal disease, or malignancy. 2
• Consider toxicology screening if drug exposure or substance abuse is suspected, though routine use is not supported by prospective data. 2

Neuroimaging Strategy

Emergent Non-Contrast CT Indications

Perform emergent head CT without contrast when any of the following high-risk features are present: 2

• Age >40 years
• Recent head trauma
• Focal seizure onset before generalization
• Fever or persistent headache
• Anticoagulation therapy
• Known malignancy or immunocompromised state
• New focal neurological deficits
• Failure to return to baseline mental status

CT abnormalities are found in 23–41% of first-time seizure presentations, and 22% of patients with normal neurologic exams still have abnormal imaging. 2

Deferred Outpatient MRI

• If the patient has returned to baseline, has a normal neurologic exam, no high-risk features, and reliable outpatient follow-up, defer neuroimaging to an outpatient MRI. 2
• MRI is the preferred modality for non-emergent evaluation because it detects epileptogenic lesions in approximately 55% of focal seizure patients, compared to only 18% with CT. 2

Electroencephalography

• Arrange an outpatient EEG as part of the neurodiagnostic work-up for every patient with an apparent first unprovoked seizure; abnormal EEG findings predict higher seizure recurrence risk. 2
• Order emergent EEG only for patients with persistent altered consciousness after seizure to detect nonconvulsive status epilepticus. 2

Lumbar Puncture

• Reserve lumbar puncture for patients with suspected meningitis or encephalitis (fever plus meningeal signs) or immunocompromised status. 2
• Perform head CT before lumbar puncture to exclude mass effect or contraindications. 2
• Routine lumbar puncture is not indicated for uncomplicated first-time seizures. 2

Antiepileptic Drug Initiation Decision

Do NOT Start AEDs in the ED for:

• Provoked seizures (seizures within 7 days of acute insult such as electrolyte abnormalities, alcohol withdrawal, toxic ingestions, or acute CNS infection)—treat the underlying precipitating condition instead. 1
• First unprovoked seizure without evidence of prior brain disease or injury—approximately one-third to one-half will have recurrence within 5 years, but starting AEDs after the first seizure prolongs time to next event without improving 5-year outcomes. 1, 2
• The number needed to treat to prevent one seizure recurrence within the first 2 years is 14, meaning many patients are exposed to medication adverse effects without proven mortality or morbidity benefit. 1, 2

Consider Starting AEDs in the ED (or Defer in Coordination with Outpatient Neurology) for:

• First unprovoked seizure with remote history of brain disease or injury (stroke, traumatic brain injury, tumor, or other CNS disease occurring >7 days ago)—these patients have higher recurrence rates, making treatment appropriate after a single event. 1, 2
• Patients with two or more unprovoked seizures on separate occasions—recurrence risk within 5 years increases from one-third to three-quarters. 1

Disposition Decisions

Safe Discharge Criteria

Discharge patients who meet ALL of the following: 1, 2

• Returned to clinical baseline in the ED
• Normal neurologic examination
• No persistent abnormal investigation results requiring inpatient management
• Reliable outpatient follow-up arranged

Admission Criteria

Admit patients with any of the following: 2

• Persistent abnormal neurologic examination
• Abnormal investigation results requiring inpatient care
• Failure to return to baseline
• Seizure recurrence within 24 hours
• Unreliable follow-up or social concerns

Seizure Recurrence Risk Counseling

• The mean time to first seizure recurrence is 121 minutes (median 90 minutes), and >85% of early recurrences occur within 6 hours of ED presentation. 2
• The overall 24-hour recurrence rate is 19%, decreasing to 9% when alcohol-related events and focal CT lesions are excluded. 2
• Nonalcoholic patients with new-onset seizures have the lowest early recurrence rate (9.4%). 2

Common Pitfalls to Avoid

• Do not assume all suspected seizures are true seizures—approximately 28–48% of suspected first seizures have alternative diagnoses (syncope, nonepileptic seizures, panic attacks). 2
• Do not miss hypoglycemia or hyponatremia—these are the only metabolic abnormalities that consistently require immediate intervention. 2
• Do not delay neuroimaging in high-risk patients—life-threatening pathology is present in nearly 1 in 4 patients with new-onset seizures. 2
• Do not label alcohol withdrawal seizures without excluding other symptomatic causes, especially in first-time seizures. 2

Outpatient Follow-Up Arrangements

• Arrange outpatient neurology follow-up within 1–2 weeks for all discharged patients. 2
• Schedule outpatient MRI and EEG before the neurology appointment to expedite definitive evaluation. 2
• Provide seizure precautions counseling: no driving (state-specific laws apply), no swimming alone, no working at heights, and avoid situations where sudden loss of consciousness could cause injury. 2