What is the recommended acute and follow‑up management for a young adult female presenting with a possible generalized tonic‑clonic seizure versus a psychogenic non‑epileptic seizure?

Management of Possible Generalized Tonic-Clonic Seizure vs. Psychogenic Non-Epileptic Seizure in a Young Adult Female

The critical first step is to distinguish true generalized convulsive seizures from psychogenic non-epileptic seizures (PNES) through detailed history from witnesses, clinical examination, and urgent EEG monitoring—ideally within 24 hours—because this distinction fundamentally determines whether antiepileptic medication is indicated or contraindicated. 1, 2

Immediate Acute Management

If Actively Seizing

• Administer benzodiazepines as first-line treatment for any seizure lasting ≥5 minutes, as seizures persisting beyond this duration are unlikely to self-terminate and represent status epilepticus 3, 4
• If seizures continue after adequate benzodiazepine dosing (refractory status epilepticus), administer second-line agents: IV fosphenytoin, levetiracetam, or valproate (all with similar 45-47% efficacy for seizure cessation within 60 minutes) 3, 5
• Avoid phenytoin and lacosamide as first-line agents due to cardiotoxicity risk when safer alternatives exist 5

If Post-Ictal or Baseline

• Stabilize airway, breathing, circulation 1
• Check fingerstick glucose immediately 5
• Obtain comprehensive metabolic panel including sodium, calcium, magnesium, and renal function 5

Diagnostic Differentiation: True Seizure vs. PNES

Clinical Features Suggesting PNES

• Longer duration of typical attack compared to epileptic seizures 6
• Significant clinical variability between episodes (>50% of PNES patients show this) 6
• Bilateral convulsive movements with apparent loss of consciousness but absence of tongue biting (only 4.2% in PNES) and ictal injury (16.7% in PNES) 6
• Identifiable psychological trigger in >60% of cases 6
• Predominantly affects women (70-80% female, ratio 2:1 to 10:1) 6, 7

Clinical Features Suggesting True Generalized Tonic-Clonic Seizure

• Stereotyped episodes with consistent semiology 1
• Tongue biting (lateral tongue) and ictal injuries are common 6
• Post-ictal confusion and drowsiness 1
• Brief duration (typically 1-3 minutes) 6

Essential Diagnostic Testing

• Obtain EEG within 24 hours of the seizure (51% yield for epileptiform abnormalities vs. 34% if delayed), followed by sleep-deprived EEG if initial study is negative 2
• Video-EEG monitoring with placebo induction (saline injection) has 95% sensitivity for confirming PNES when typical habitual attack occurs without electroclinical correlate 6
• Brain MRI should be obtained in outpatient setting for all patients except those with confirmed idiopathic generalized epilepsy 1, 2
• MRI identifies epileptogenic lesions in approximately 13% of first-seizure patients, including tumors 2

Classification: Provoked vs. Unprovoked Seizure

Provoked (Acute Symptomatic) Seizures

Occurring within 7 days of acute insult 3, 1:

• Electrolyte abnormalities: hyponatremia, hypocalcemia, hypomagnesemia 5
• Medication-related: tramadol, SSRIs (particularly vilazodone), alcohol withdrawal 5
• Metabolic: hypoglycemia, hyperglycemia, uremia 5
• CNS insults: intracranial hemorrhage, encephalitis, mass lesions 1

Unprovoked Seizures

• No acute precipitating factors 1
• May include remote symptomatic seizures (>7 days from CNS injury, stroke, traumatic brain injury) 3

Antiepileptic Medication Decision Algorithm

DO NOT Initiate Antiepileptic Drugs If:

• PNES is confirmed (conversion disorder accounts for 70% of PNES cases; these patients require psychiatric referral, not antiepileptic drugs) 6
• Provoked seizure with correctable cause (treat the underlying condition instead) 3, 5
• First unprovoked seizure without brain disease/injury (NNT=14 to prevent one recurrence in 2 years; early treatment only delays but doesn't prevent recurrence at 5 years) 3, 1

MAY Initiate or Defer Antiepileptic Drugs If:

• First unprovoked seizure WITH remote history of brain disease or injury (stroke, traumatic brain injury, cerebral palsy) 3
• Coordinate decision with neurology follow-up 3

SHOULD Initiate Antiepileptic Drugs If:

• Two or more unprovoked seizures (recurrence risk increases from 33-50% to 75% within 5 years) 3, 1
• Levetiracetam is recommended as first-line monotherapy for recurrent unprovoked seizures 1

Admission Decision Algorithm

DO NOT Admit If:

• First unprovoked seizure with return to clinical baseline in ED 3, 1
• PNES confirmed without safety concerns 6

ADMIT If:

• Underlying brain disorder present (observe for at least 6 hours, preferably 24 hours, as >85% of early recurrences occur within 6 hours) 1
• Provoked seizure with uncorrected underlying cause 1
• Recurrent seizures or incomplete recovery to baseline 1
• Status epilepticus or refractory seizures 3

Special Management Considerations for PNES

• Avoid prolonged antiepileptic drug treatment (20% of isolated PNES patients are inappropriately treated with ≥2 antiepileptic drugs for average of 2.4 years) 6
• Psychiatric evaluation is essential: conversion disorder (70%), somatization disorder, factitious disorder, or dissociative disorders are the underlying diagnoses 6, 7
• Coexisting epilepsy occurs in 9-37.5% of PNES patients, requiring careful EEG differentiation 6, 7
• Average diagnostic delay is 4.5-7 years, leading to unnecessary medication exposure and healthcare costs 6, 7

Disposition and Follow-Up

• Urgent neurology follow-up within 1-2 weeks for all first-seizure patients 1
• Outpatient brain MRI and EEG if not obtained in ED 1, 2
• For confirmed PNES: psychiatric or psychology referral for cognitive-behavioral therapy 6, 7
• Patient education on avoiding seizure triggers (sleep deprivation, substance use, medication non-compliance) 5

Critical Pitfalls to Avoid

• Misdiagnosing PNES as epilepsy leads to years of unnecessary antiepileptic drug exposure (10-20% of "therapy-resistant epilepsy" referrals are actually PNES) 7
• Initiating antiepileptic drugs for first unprovoked seizure without brain injury provides minimal benefit (NNT=14) and exposes patients to medication side effects 3, 1
• Delaying EEG beyond 24 hours reduces diagnostic yield by 33% 2
• Assuming alcohol withdrawal without thorough evaluation—this should be a diagnosis of exclusion, particularly in first-time presentations 5
• Missing coexisting epilepsy in PNES patients (occurs in up to 37.5% of cases) 6