Seizures

Seizure Emergencies: Clinical Framework and Exam Focus

Seizures are a common neurological emergency in the emergency department (ED), accounting for approximately 1–2% of all ED visits.^[1] The Certified Emergency Nurse (CEN) exam tests recognition of seizure types, prioritization of interventions, management of status epilepticus, and complication prevention. High-yield topics include the ABCDE approach, pharmacologic termination of seizures, and differentiation from mimics (e.g., syncope, psychogenic nonepileptic seizures).

Seizure Classification and Status Epilepticus Criteria

2.1 Seizure vs. Epilepsy

• Seizure: A transient occurrence of signs/symptoms due to abnormal, excessive, or synchronous neuronal activity in the brain.^[2]
• Epilepsy: A chronic brain disorder characterized by recurrent, unprovoked seizures (≥2 unprovoked seizures >24 h apart).^[3]
• Provoked seizure: Caused by an acute identifiable trigger (e.g., hypoglycemia, electrolyte imbalance, drug intoxication, fever).

2.2 Seizure Classification (ILAE 2017)

• Focal onset (previously partial) – originates in one hemisphere; may become bilateral tonic-clonic.
• Generalized onset – rapidly involves both hemispheres; includes tonic-clonic, absence, myoclonic, atonic, clonic, tonic.
• Unknown onset – insufficient information to classify.

2.3 Status Epilepticus (SE)

• Defined as ≥5 minutes of continuous clinical or electrographic seizure activity, or ≥2 seizures without full return to baseline.^[1]
• Medical emergency: Requires immediate intervention to prevent neuronal injury and systemic complications.

Seizure Emergency Management Stepwise Protocol

3.1 Emergency Management Algorithm for Seizures

1. ABCs and stabilization: Assess airway, breathing, circulation. Position patient on side (aspiration prevention). Administer oxygen if hypoxic. Establish IV access.^[4]
2. Seizure termination: If seizure continues beyond 5 minutes (impending SE), administer a benzodiazepine as first-line therapy.
3. Post-seizure assessment: Check blood glucose, electrolyte panel, and toxicology screen. Obtain CT head if indicated (new focal deficit, trauma, anticoagulation).
4. Secondary prevention: Start maintenance antiseizure drug (ASD) per neurologist guidance if needed.
5. Identify and treat cause: Hypoglycemia, hyponatremia, drug withdrawal, infection (CNS or systemic), stroke.

3.2 Status Epilepticus Stepwise Protocol

• 0–5 min: Assess ABCs, draw labs, check glucose.
• 5–10 min: Give benzodiazepine (IV lorazepam 0.1 mg/kg up to 4 mg, or IM midazolam 10 mg if no IV).^[5]
• 10–20 min: If ongoing, administer second-line agent: IV fosphenytoin (20 mg PE/kg), levetiracetam (60 mg/kg), or valproate (40 mg/kg).^[1]
• >20 min: If refractory, consider continuous EEG, IV anesthetic (propofol, midazolam infusion, or pentobarbital) with ICU admission.

Clinical Presentation of Seizure Subtypes

4.1 Focal Onset Seizure

• Aware: Patient conscious; may report aura (e.g., déjà vu, epigastric rising, odd smell).
• Impaired awareness: Altered consciousness; automatisms (lip smacking, picking).
• Motor onset: Clonic, tonic, or myoclonic jerking limited to one limb or face.
• Nonmotor onset: Sensory, autonomic, or psychic symptoms.

4.2 Generalized Tonic-Clonic Seizure

• Tonic phase: Stiffening, cyanosis, upward eye deviation.
• Clonic phase: Rhythmic jerking of extremities.
• Postictal phase: Confusion, drowsiness, headache, muscle soreness; may last minutes to hours.
• Potential findings: Tongue biting, urinary incontinence, elevated lactate, respiratory acidosis.

4.3 Absence Seizure

• Brief (seconds) staring spell; no postictal confusion; may be mistaken for inattention.
• More common in children; hyperventilation can provoke.

Seizure Diagnostic Workup: History, Exam, and Testing

5.1 History and Physical Exam

• Focus on eyewitness description: onset, duration, movements, eye deviation, color change, postictal period.
• Ask about triggers (sleep deprivation, alcohol withdrawal, medication noncompliance), past seizure history, recent fever or headache.
• Neurological exam: assess level of consciousness, focal deficits, nystagmus, signs of increased ICP.
• Check for injuries (tongue laceration, shoulder dislocation, vertebral fractures).

5.2 Diagnostic Studies

• Blood glucose: Fingerstick immediately – hypoglycemia is a common cause.
• Complete blood count, basic metabolic panel, calcium, magnesium, liver/renal function: Identify metabolic/electrolyte abnormalities.
• Toxicology screen: Rule out stimulant or anticholinergic poisoning.
• Antiseizure drug levels: If patient is on therapy and breakthrough seizure suspected.
• Noncontrast head CT: Indicated for first-time seizure, new focal deficit, trauma, anticoagulation, age >40, fever, or HIV.^[4]
• EEG: Nonemergent unless concern for nonconvulsive status epilepticus; urgent EEG if patient does not return to baseline.

Seizure Pharmacotherapy and Supportive Care Protocol

6.1 Pharmacologic Therapy

• First-line benzodiazepine:
  • IV lorazepam 0.1 mg/kg (max 4 mg) – preferred.^[5]
  • IV diazepam 0.15–0.2 mg/kg (max 10 mg).
  • IM midazolam 10 mg if no IV access.^[5]
  • Rectal diazepam or intranasal midazolam for pediatric or out-of-hospital use.
• Second-line antiseizure drugs (if seizure persists):
  • IV fosphenytoin 20 mg PE/kg (300 mg PE over 5–10 min) – watch for hypotension, arrhythmias.^[1]
  • IV levetiracetam 60 mg/kg (max 4500 mg) – well-tolerated, fewer drug interactions.
  • IV valproic acid 40 mg/kg (if contraindications absent).
• Refractory SE (failure of two ASD doses):
  • Continuous propofol infusion (1–2 mg/kg bolus, then 20–200 mcg/kg/min).
  • Midazolam infusion (0.2 mg/kg bolus, then 0.05–2 mg/kg/h).
  • Pentobarbital coma (5–15 mg/kg bolus, then 0.5–5 mg/kg/h) – requires ICU.

6.2 Supportive Care and Monitoring

• Maintain airway: Consider head-tilt/chin-lift; place oral airway only if obtunded postictal; avoid during active clonic phase.
• Continuous pulse oximetry, cardiac monitoring.
• Blood glucose management: Correct hypoglycemia with IV dextrose (50 mL D50) or thiamine (100 mg) if alcoholic or malnourished.
• Core temperature monitoring: Frequent/prolonged seizures can cause hyperthermia.
• Prepare for possible emergent intubation if status epilepticus persists with respiratory compromise.

Seizure Safety Measures and Complication Management

7.1 Patient Safety During Seizure

• Do not restrain forcefully – may lead to fracture or injury.
• Remove hazards (sharp objects, IV lines if possible); pad side rails.
• Place in lateral decubitus position to allow drainage of secretions.
• Never insert anything into the patient’s mouth (including fingers, bite blocks) – can cause aspiration or dental trauma.

7.2 Common Complications

• Airway obstruction from tongue or secretions – need suction and positioning.
• Respiratory depression from benzodiazepines – monitor respiratory rate and oxygen saturation; have bag-valve-mask ready.
• Hypotension from fosphenytoin or propofol – consider fluid bolus and vasopressors.
• Rhabdomyolysis from prolonged seizure – check creatine kinase, ensure IV fluids.
• Nonconvulsive status epilepticus – suspect if patient does not awaken after 30 min; obtain EEG.^[3]
• SUDEP (sudden unexplained death in epilepsy) – rare but related to generalized tonic-clonic seizures, often at night.

CEN Exam Strategies: Seizure Prioritization and Differential Diagnosis

• First priority: Secure airway and stop the seizure – do not wait for lab results before giving benzodiazepine if seizure >5 min.
• Differentiate seizure from syncope: Syncope – rapid onset, brief loss of tone, no postictal confusion; seizure – prolonged, rhythmic jerking, confusion after.
• Know benzodiazepine doses: Lorazepam 4 mg IV; midazolam 10 mg IM; diazepam 5–10 mg IV.
• Remember “ABC – Benzo – Labs – CT”: Sequential approach for exam questions.
• Pseudoseizures (psychogenic nonepileptic seizures): Suggest by lack of postictal confusion, intermittent flailing, closed eyes (resisting opening), but may coexist with epilepsy – avoid labeling without EEG.
• Pediatric considerations: Febrile seizures (age 6 mo–5 yr, generalized, <15 min) – usual management for simple febrile seizure is reassurance, not medication.
• High-yield lab: Serum glucose – most common correctable metabolic cause in ED.
• Post-seizure driving restrictions: Typically no driving for ≥6 months under state law; document counseling.

References and Sources

1. Emergency Nurses Association. (2022). Clinical Practice Guideline: Management of the Patient with Seizures in the Emergency Department. Journal of Emergency Nursing, 48(4), 394–405. https://doi.org/10.1016/j.jen.2022.03.001
2. Fisher, R. S., Acevedo, C., Arzimanoglou, A., et al. (2014). ILAE official report: a practical clinical definition of epilepsy. Epilepsia, 55(4), 475–482. https://doi.org/10.1111/epi.12550
3. Huff, J. S., & Fountain, N. B. (2011). Pathophysiology and management of seizures and status epilepticus. In Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7th ed. (Chapter 176). McGraw-Hill. https://doi.org/10.1036/0071485242
4. American College of Emergency Physicians. (2021). Clinical Policy for the Initial Evaluation and Management of Patients Presenting with Seizures in the Emergency Department. Annals of Emergency Medicine, 78(1), S1–S19. https://doi.org/10.1016/j.annemergmed.2021.03.016
5. Glauser, T., Shinnar, S., Gloss, D., et al. (2016). Evidence-based guideline: treatment of convulsive status epilepticus in children and adults: report of the Guideline Committee of the American Epilepsy Society. Epilepsy Currents, 16(1), 48–61. https://doi.org/10.5698/1535-7597-16.1.48