How to manage a seizure in a patient with potential underlying neurological disorders and considering their past medical history?

Management of Seizures

For an active seizure lasting >5 minutes, immediately administer benzodiazepines (lorazepam 4 mg IV preferred) as first-line therapy, followed by second-line agents (levetiracetam, valproate, or fosphenytoin—all equally effective) if seizures persist, while simultaneously checking glucose and identifying reversible causes. 1, 2

Immediate Actions During Active Seizure

Safety and Positioning

• Help the seizing patient to the ground, place them on their side in recovery position, and clear the surrounding area to minimize injury risk 3
• Stay with the patient throughout the seizure 3
• Never restrain the patient or place anything in their mouth—these actions cause harm 3
• Have airway equipment immediately available before administering benzodiazepines due to respiratory depression risk 2

Emergency Medical Services Activation

Activate EMS for: first-time seizure, seizures lasting >5 minutes, multiple seizures without return to baseline between episodes, seizures in water, traumatic injuries during seizure, difficulty breathing, choking, seizures in infants <6 months, seizures in pregnant patients, or failure to return to baseline within 5-10 minutes after seizure stops 3

Pharmacologic Management Algorithm

First-Line: Benzodiazepines (for seizures >5 minutes)

• Lorazepam 0.1 mg/kg IV (typically 4 mg) at 2 mg/min is the preferred benzodiazepine with 65% efficacy in terminating status epilepticus, superior to diazepam (59.1% vs 42.6%) 1, 2
• Lorazepam has longer duration of action compared to other benzodiazepines 1

Second-Line Agents (if seizures persist after benzodiazepines)

All three second-line agents have equivalent efficacy (45-47% seizure cessation at 60 minutes), so selection should be based on safety profile and patient-specific contraindications 2:

• Levetiracetam 60 mg/kg IV (maximum 4500 mg) over 10 minutes: hypotension risk 0.7%, intubation rate 20% 2
• Valproate 40 mg/kg IV (maximum 3000 mg) over 10 minutes: hypotension risk 1.6%, intubation rate 16.8% 2
• Fosphenytoin 20 mg PE/kg IV at maximum rate 150 mg/min: hypotension risk 3.2%, intubation rate 26.4% (preferred over phenytoin due to faster infusion and lower hypotension risk) 1, 2

Third-Line: Anesthetic Agents for Refractory Status Epilepticus

For seizures continuing despite benzodiazepines and one second-line agent 2:

• Midazolam: loading dose 0.15-0.20 mg/kg IV, continuous infusion 1 mg/kg/min, titrate up by 1 mg/kg/min every 15 minutes to maximum 5 mg/kg/min 2
• Propofol: loading dose 2 mg/kg bolus, continuous infusion 3-7 mg/kg/hour 2
• Pentobarbital: loading dose 13 mg/kg, continuous infusion 2-3 mg/kg/hour 2
• Initiate continuous EEG monitoring at this stage to guide therapy and detect non-convulsive seizure activity 2

Simultaneous Diagnostic Workup

Immediate Bedside Testing

• Check fingerstick glucose immediately in all seizure patients—hypoglycemia is a common, rapidly reversible cause 1, 2
• Document seizure duration from onset and semiology (focal versus generalized) 1

Search for Reversible Causes

Identify and treat underlying etiologies while administering anticonvulsants 1, 2:

• Metabolic causes: hypoglycemia, hyponatremia, hypocalcemia, hypomagnesemia 1
• Toxic causes: consider toxicology screen if ingestion suspected 1
• Infectious causes: CNS infection, encephalitis 4
• Structural causes: intracranial hemorrhage, CNS mass lesions, stroke 4
• Withdrawal syndromes: alcohol, benzodiazepines 3, 4

Neuroimaging

• Obtain head CT in the emergency department for first-time seizure patients, patients >60 years, and those with focal neurologic deficits 1
• MRI is preferred when neuroimaging is obtained due to higher sensitivity for structural lesions 1
• Do not delay anticonvulsant administration for imaging 2

EEG Considerations

• Consider emergent EEG for patients with persistent altered consciousness after seizure termination, those who received long-acting paralytics, and those in drug-induced coma 1
• Non-convulsive status epilepticus should be considered in any patient with unexplained confusion or coma 1

Classification: Provoked vs. Unprovoked Seizures

Provoked Seizures

Seizures occurring at the time of or within 7 days of an acute neurologic, systemic, metabolic, or toxic insult, such as hyponatremia, withdrawal, toxic ingestions, encephalitis, CNS mass lesions, or intracranial hemorrhage 4

Unprovoked Seizures

Seizures without acute precipitating factors, including remote symptomatic seizures from CNS/systemic insult >7 days past, such as prior stroke, traumatic brain injury, or cerebral palsy 4

Decision to Initiate Long-Term Antiepileptic Therapy

First Unprovoked Seizure

• Do not initiate long-term antiepileptic drugs after a first unprovoked seizure in the ED—early treatment only prolongs time to next event without changing 5-year outcomes 4, 1
• The number needed to treat to prevent one seizure recurrence in the first 2 years is 14 patients 4
• Exception: For patients with first unprovoked seizure and remote history of brain disease or injury (stroke, traumatic brain injury, cerebral palsy), antiepileptic medication may be initiated or deferred to outpatient neurology 4, 1

Recurrent Unprovoked Seizures

Patients with 2-3 recurrent unprovoked seizures have substantially increased recurrence risk and should receive antiepileptic therapy, with levetiracetam recommended as first-line monotherapy 4

Provoked Seizures

Do not start prophylactic anticonvulsants for provoked seizures—treatment is aimed at correction of the underlying cause with appropriate short-term anticonvulsant medication 1

Hospital Admission Criteria

Admit the Following Patients:

• Status epilepticus requiring multiple medications 1
• Persistent altered mental status after seizure 1
• Acute symptomatic causes requiring treatment 1
• Refractory seizures 1
• Patients with underlying brain disorders (observe for at least 6 hours, preferably 24 hours, as >85% of early seizure recurrences occur within 6 hours) 4
• Recurrent seizures or incomplete recovery 4

Safe for Discharge:

Patients with first unprovoked seizure who have returned to clinical baseline in the ED do not require hospital admission 4

Disposition and Follow-Up

• Urgent neurology follow-up within 1-2 weeks is recommended for all patients with a first seizure 4
• Brain MRI and EEG should be obtained in the outpatient setting to characterize structural abnormalities and assess for epileptiform activity 4

Special Populations

Febrile Seizures in Children

Administration of antipyretics (acetaminophen, ibuprofen, or paracetamol) is not effective for stopping a febrile seizure or preventing subsequent febrile seizures 3

Pregnant Patients

Activate EMS for any seizure in pregnant individuals 3

Critical Pitfalls to Avoid

• Do not delay benzodiazepines if seizure exceeds 5 minutes—mortality increases significantly in refractory cases (5-22% overall, reaching 65% in refractory status epilepticus) 1, 2
• Do not miss non-convulsive status epilepticus, which should be considered in any patient with unexplained confusion or coma 1
• Do not start prophylactic anticonvulsants in stroke patients—they may negatively affect neurological recovery 1
• Do not give oral medications, food, or liquids to a person experiencing a seizure or with decreased responsiveness after a seizure 3
• Phenytoin is ineffective for seizures secondary to alcohol withdrawal, theophylline toxicity, or isoniazid toxicity 5

Prognosis

• Mortality from status epilepticus ranges from 5-22%, reaching 65% in refractory cases 2
• Approximately 16-26% of patients with status epilepticus require endotracheal intubation 2
• Continuous vital sign monitoring is essential, particularly respiratory status and blood pressure 2