What is the immediate management for a patient presenting with generalized tonic-clonic (GTC) seizures, tachycardia, and headache?

Immediate Management of GTC Seizure with Tachycardia and Headache

Administer benzodiazepines immediately if the seizure is ongoing or recurrent, as status epilepticus (defined as seizure activity >5 minutes or recurrent seizures without return to baseline) carries a mortality rate of 5-22% if untreated, and up to 65% if refractory. 1

Acute Seizure Termination

• Lorazepam 0.1 mg/kg IV (maximum 4 mg) at 2 mg/min is the first-line agent for active seizures 2, 3
• If seizures persist after initial benzodiazepine dose, repeat lorazepam 4 mg IV slowly after a 10-15 minute observation period 3
• Continuous monitoring of ECG, blood pressure, and respiratory function is essential during benzodiazepine administration 4
• Airway patency must be assured and ventilatory support equipment immediately available, as respiratory depression is the most important risk 3

Urgent Diagnostic Workup

Immediately obtain the following to identify reversible causes:

• Fingerstick glucose to rule out hypoglycemia as a seizure trigger 2
• Electrolytes (sodium, calcium, magnesium) as hyponatremia and hypocalcemia are common seizure precipitants 1, 2
• Renal function to assess for metabolic derangements 1
• ECG to evaluate the tachycardia and rule out cardiac arrhythmia as a cause of syncope versus seizure 5

Distinguishing Seizure from Syncope

The combination of tachycardia and headache requires careful evaluation, as both seizures and syncope can present with these features:

• Tonic-clonic movements that are prolonged and coincide with loss of consciousness suggest seizure 5
• Brief tonic-clonic movements (<15 seconds) starting after loss of consciousness suggest syncope 5
• Post-ictal confusion, muscle aching, and headache are more frequent after epilepsy 5
• Sinus tachycardia occurs in 41.2% of patients after GTCS 6

Cardiac Evaluation

Given the tachycardia, urgent cardiovascular assessment is warranted:

• Obtain 12-lead ECG to evaluate for arrhythmia, conduction abnormalities, or signs of cardiac ischemia 5
• Consider troponin I measurement, as it is elevated in 12% of patients post-GTCS, particularly in older patients 6
• Post-ictal atrial fibrillation can occur after GTCS and may require cardioversion 7
• If ECG shows concerning features (conduction abnormality, QT prolongation, or arrhythmia during exercise history), urgent cardiology consultation is required 5

Neuroimaging Indications

CT head without contrast is mandatory if:

• New focal neurologic deficits are present 2
• Recent head trauma occurred 2
• Persistent altered mental status beyond expected post-ictal period 5
• First seizure in patient >60 years old 5

CT head is NOT routinely indicated for patients who have returned to baseline after an uncomplicated first seizure 5

Second-Line Antiepileptic Therapy

If seizures persist after benzodiazepines, administer one of the following:

• Phenytoin 15-20 mg/kg IV at rate not exceeding 50 mg/min (adult) or 1-3 mg/kg/min (pediatric) 4
• Levetiracetam is an alternative second-line agent 2, 8
• Valproate is another option for refractory seizures 2, 8

Critical Monitoring During Phenytoin Administration

• Continuous ECG monitoring is mandatory, as phenytoin is contraindicated in sinus bradycardia, sino-atrial block, and second/third-degree AV block 4
• Monitor blood pressure and respiratory function throughout infusion 4

Management of Headache

The headache in this context is likely post-ictal:

• Headache is more frequent after epileptic seizures compared to syncope 5
• Evaluate for intracranial hemorrhage if headache is severe, sudden-onset, or associated with focal deficits 2
• Post-ictal headache typically resolves without specific intervention

Disposition Decisions

Hospital admission is required if:

• Multiple or recurrent seizures occurred 5, 1
• Persistent tachycardia or cardiac arrhythmia is present 7
• Metabolic abnormalities requiring correction are identified 1
• First unprovoked seizure with concerning features (age >60, abnormal neurologic exam, abnormal ECG) 5
• Patient has not returned to baseline mental status 5, 9

Discharge may be appropriate if:

• Single brief self-limited seizure with identified reversible cause 9
• Patient has returned to baseline mental status 9
• No cardiac abnormalities on ECG 5
• No concerning neurologic findings 5

Antiepileptic Drug Initiation

Do NOT routinely start long-term antiepileptic drugs for:

• Single provoked seizure (e.g., from electrolyte abnormality, hypoglycemia) 9, 2
• First unprovoked seizure without high-risk features 5

DO initiate antiepileptic therapy for:

• Evidence of structural brain disease (hemorrhage, infarct, mass) 2
• Recurrent unprovoked seizures 1
• Levetiracetam is the preferred long-term agent for GTCS per American Academy of Neurology recommendations 1

Common Pitfalls to Avoid

• Do not obtain routine EEG in the emergency setting for patients who have returned to baseline after a provoked seizure 9
• Do not start prophylactic anticonvulsants for patients with no history of seizures who are not undergoing neurosurgery 5
• Do not delay benzodiazepine administration while waiting for laboratory results if seizure is ongoing 1, 3
• Do not miss cardiac causes of loss of consciousness by assuming all events with tonic-clonic movements are primary seizures 5