What is the appropriate management for a patient with a history of seizures, considering their age and underlying medical conditions?

Management of Seizures in Adults

For patients with a history of seizures presenting with breakthrough seizures, immediately assess for and correct metabolic triggers (hypocalcemia, hyponatremia, hypomagnesemia, hypoglycemia), then optimize their existing antiepileptic medication regimen rather than routinely adding new agents unless they are in status epilepticus. 1, 2

Immediate Assessment and Stabilization

Vital Signs and Safety

• Ensure airway, breathing, and circulation are stable 3
• Document Glasgow Coma Scale score, as GCS <15 indicates higher risk of early seizure recurrence 3
• Record seizure characteristics: duration, focal versus generalized onset, motor activity, and post-ictal state 3

Critical Laboratory Evaluation

Check these metabolic parameters immediately, as they are reversible seizure triggers:

• Serum glucose and sodium on all patients 1, 3
• Ionized calcium, magnesium, and renal function (creatinine, BUN) 1
• Hypocalcemia can trigger seizures at any age, even without prior history, and typically resolves with supplementation alone 4, 1
• Hyponatremia, hypomagnesemia, uremia, and hyperglycemia are significant provoked seizure causes 1, 2

Management Based on Seizure Type

Status Epilepticus (Seizure >5-20 minutes or recurrent without recovery)

First-line treatment: Benzodiazepines 4

Second-line treatment after benzodiazepine failure (Level A recommendation):

• Administer an additional antiepileptic medication 4

Preferred second-line agents (Level B recommendation):

• IV valproate 20-30 mg/kg at 6 mg/kg/hour: 88% seizure cessation rate, superior to phenytoin (79% vs 25% as second-line), no hypotension risk 4
• IV phenytoin/fosphenytoin 18-20 mg/kg at 50 mg/min: Traditional choice but only 56% success rate and causes hypotension in 12% of patients 4

Alternative second-line agents (Level C recommendation):

• IV levetiracetam 30 mg/kg at 5 mg/kg/min: 73% seizure cessation, comparable to valproate (68%), fewer adverse effects 4, 5
• Propofol or barbiturates for refractory cases 4

Critical pitfall: Phenytoin is ineffective for alcohol withdrawal seizures and toxin-induced seizures (theophylline, isoniazid) 2

Breakthrough Seizures in Known Epilepsy

Do not automatically add or load antiepileptic medications. The evidence does not support routine loading in the ED for preventing early recurrent seizures, and route of administration (oral vs parenteral) does not affect outcomes 4

Instead, focus on:

• Identifying and correcting metabolic triggers (see above) 1, 2
• Assessing medication compliance
• Searching for acute provoking factors: infection, stroke, hemorrhage, trauma, medication changes 4, 2

First Unprovoked Seizure

The World Health Organization explicitly recommends against routine prescription of antiepileptic drugs after a first unprovoked seizure 6

Rationale:

• Only one-third to one-half will have recurrence within 5 years 6
• Treatment reduces recurrence risk by approximately half but does not affect long-term outcomes at 5 years 6
• Number needed to treat to prevent one recurrence in 2 years is 14 patients 6

Observation period:

• Mean time to first recurrence is 121 minutes (median 90 minutes) 3, 6
• 85% of early recurrences occur within 6 hours 6
• Keep patients under observation during this high-risk window 3, 6

Neuroimaging Requirements

Perform brain neuroimaging in the ED for first-time seizures (Level B recommendation): 3

• Age >40 years
• History of malignancy or immunocompromise
• Anticoagulation therapy
• New focal neurologic deficits
• Acute head trauma
• Persistent headache or fever
• Focal seizure onset before generalization

Deferred outpatient neuroimaging is acceptable when reliable follow-up exists (Level B recommendation) 3

Disposition Decisions

Safe for Discharge (Level C recommendation):

• First unprovoked seizure with return to clinical baseline 3
• Normal neuroimaging (or deferred with reliable follow-up) 3
• No high-risk features for early recurrence 3

Requires Admission:

• Abnormal neuroimaging findings 3
• Persistent neurologic deficits 3
• Provoked seizures requiring treatment of underlying cause 3
• High risk for early recurrence: alcoholism, GCS <15, age ≥40, hyperglycemia, history of CNS injury 3, 6
• Status epilepticus or refractory seizures 4

Special Populations

22q11.2 Deletion Syndrome

• Lifetime epilepsy prevalence 5-7% (vs 0.5-1% general population) 4
• Hypocalcemia is a critical trigger at any age due to underlying parathyroid dysfunction 4
• Hypocalcemic seizures resolve with calcium/vitamin D supplementation alone; anticonvulsants only if seizures persist after calcium normalization 4
• Check ionized calcium, magnesium, parathyroid hormone, and creatinine regularly 4
• Increased risk during biological stress: surgery, childbirth, infection 4

Women of Childbearing Potential

• Obtain pregnancy test 1
• Avoid valproate if possible 6

Common Pitfalls to Avoid

• Do not routinely treat first unprovoked seizures—the default should be observation and neurology follow-up 6
• Do not use phenytoin for alcohol withdrawal or toxin-induced seizures 2
• Do not overlook hypocalcemia—it can occur at any age without prior history 4, 1
• Do not assume epilepsy—most provoked seizures do not represent epilepsy and require only short-term treatment while correcting the underlying cause 2
• Do not forget to check for non-convulsive status epilepticus in confused or comatose patients of unclear etiology; obtain EEG promptly 2