What is the initial workup for a patient presenting with a seizure in the Emergency Department (ED)?

Initial Emergency Department Workup for Patients with Seizures

The initial workup for a patient presenting with a seizure in the Emergency Department should include serum glucose and sodium levels, pregnancy testing for women of childbearing age, and neuroimaging when feasible. 1

Laboratory Testing

• Determine serum glucose and sodium levels for all patients with seizures, as these are the most frequent abnormalities identified and can directly cause seizures 1, 2
• Obtain a pregnancy test for all women of childbearing age, as pregnancy status affects testing, disposition, and medication decisions 1, 2
• Consider toxicology screening when drug exposure or substance abuse is suspected 2
• Perform a lumbar puncture, after head CT, for patients who are immunocompromised or when meningitis/encephalitis is suspected 1, 2
• Routine testing for calcium, magnesium, or phosphate levels is not supported by evidence in otherwise healthy patients 1
• Consider checking urine for blood to detect evidence of rhabdomyolysis, which can be a complication of seizures 1

Neuroimaging

• When feasible, perform neuroimaging of the brain in the ED for patients with a first-time seizure 1
• Head CT should be performed emergently when an acute intracranial process is suspected, particularly in patients with 1:
  • History of acute head trauma
  • History of malignancy
  • Immunocompromised status
  • Fever
  • Persistent headache
  • History of anticoagulation
  • New focal neurologic examination
  • Age older than 40 years
  • Focal onset before generalization
• Deferred outpatient neuroimaging may be considered only when reliable follow-up is available 1
• MRI is the preferred imaging modality for non-emergent situations 2

Disposition Decisions

• Patients with a first unprovoked seizure who have returned to their clinical baseline in the ED may not require admission 2
• Consider admission if any of the following are present 2:
  • Persistent abnormal neurologic examination
  • Abnormal investigation results
  • Patient has not returned to baseline
• The mean time to first seizure recurrence is 121 minutes (median 90 minutes) with more than 85% of early seizures recurring within 6 hours 2
• Non-alcoholic patients with new-onset seizures have the lowest early seizure recurrence rate (9.4%) 2

Common Pitfalls to Avoid

• Failing to identify metabolic abnormalities such as hypoglycemia or hyponatremia that may be causing the seizure 2
• Missing structural lesions by not performing appropriate neuroimaging 2
• Diagnosing alcohol withdrawal seizures without excluding other causes, especially in patients presenting with a first-time seizure 1
• Discharging patients without ensuring adequate follow-up, which can lead to increased readmission rates 3
• Failing to communicate with the patient's primary care physician or neurologist about the ED visit, which disrupts continuity of care 4

Special Considerations

• For patients with known epilepsy presenting with a breakthrough seizure, communication between emergency physicians, neurologists, and primary care physicians is critical for continuity of care 4
• Seizure care pathways in the ED can reduce unnecessary admissions, length of stay, and readmission rates 3
• For patients with status epilepticus (seizure lasting >5 minutes or multiple seizures without return to baseline), prompt treatment with benzodiazepines is essential 1

By following this structured approach to the evaluation of patients with seizures in the ED, clinicians can ensure appropriate diagnostic testing while avoiding unnecessary procedures, ultimately improving patient outcomes and resource utilization.