Epilepsy and seizures

Quick Overview

Epilepsy is a neurological disorder characterized by recurrent unprovoked seizures (≥2 seizures >24 hours apart). Status epilepticus (SE) is a life-threatening emergency requiring immediate intervention. NICE NG217 provides evidence-based guidance on diagnosis, when to initiate treatment, first-line AED selection, and legal driving requirements-all critical for safe, effective management.

Core Facts & Concepts

Definitions & Thresholds

• Epilepsy diagnosis: ≥2 unprovoked seizures >24 hours apart OR 1 seizure + high recurrence risk (>60% over 10 years)
• Status epilepticus: Seizure lasting ≥5 minutes OR ≥3 seizures in 1 hour without full recovery
• Provoked seizure: Identifiable acute cause (hypoglycemia, alcohol withdrawal, acute stroke, CNS infection)

Seizure Classification (ILAE 2017)

First-Line AED Selection (NICE NG217)

• Focal seizures: Lamotrigine or levetiracetam (carbamazepine if unsuitable)
• Generalized tonic-clonic: Sodium valproate (males), lamotrigine/levetiracetam (females of childbearing potential)
• Absence seizures: Ethosuximide or sodium valproate
• Myoclonic seizures: Sodium valproate or levetiracetam

⚠️ Warning: Avoid sodium valproate in women of childbearing potential unless Pregnancy Prevention Programme in place (teratogenicity risk 30-40%)

Problem-Solving Approach

Status Epilepticus Emergency Protocol (NICE NG217)

1. 0-5 minutes: ABCDE approach, secure airway, high-flow O₂, check glucose, IV access
2. 5-10 minutes: Benzodiazepine (first-line)
   • IV lorazepam 4mg (repeat once after 10 minutes if ongoing)
   • Alternatives: Buccal midazolam 10mg OR rectal diazepam 10-20mg
3. 10-25 minutes: If seizure continues after 2 benzodiazepine doses → second-line
   • IV levetiracetam 60mg/kg (max 4.5g) OR
   • IV phenytoin 20mg/kg (max rate 50mg/min) OR
   • IV valproate 40mg/kg (max 3g)
4. 25+ minutes: Refractory SE → call anesthetics for intubation, propofol/thiopental, ICU transfer


When to Start Treatment After First Seizure

• Start AED if: Brain imaging abnormality, EEG showing epileptiform activity, nocturnal seizure, or recurrence risk >60%
• Otherwise: Discuss risks/benefits; many clinicians defer until second seizure

Analysis Framework

Differential Diagnosis: Seizure vs. Syncope vs. Non-Epileptic Attack

Red Flags Requiring Urgent Investigation

• 🚩 First seizure in adult >25 years (exclude tumor, stroke)
• 🚩 Focal neurology (suggests structural lesion)
• 🚩 Persistent fever/headache (CNS infection)
• 🚩 Head trauma within 3 months

Visual Aid

Driving Regulations (DVLA - UK)

Key Points Summary

✓ Status epilepticus: Treat at 5 minutes with IV lorazepam 4mg (repeat once); second-line at 10-25 minutes with levetiracetam/phenytoin/valproate

✓ First-line AEDs: Focal = lamotrigine/levetiracetam; Generalized TC = valproate (males) or lamotrigine (females); Absence = ethosuximide

✓ Start AED after first seizure if: Brain lesion, epileptiform EEG, nocturnal seizure, or recurrence risk >60%

✓ Avoid valproate in women of childbearing age unless Pregnancy Prevention Programme (30-40% teratogenicity risk)

✓ Driving: Group 1 requires 12 months seizure-free; Group 2 requires 10 years off AEDs

✓ Lateral tongue biting + post-ictal confusion strongly suggest true epileptic seizure vs. syncope/non-epileptic attack

✓ Red flags: First seizure >25 years, focal neurology, fever/headache → urgent imaging/LP to exclude tumor/stroke/infection