Seizure Disorders and Epilepsy

Definitions & Classification - Seizure Starters

• Seizure: Transient event from abnormal, excessive/synchronous brain neuronal activity.
• Epilepsy: ≥2 unprovoked seizures >24h apart; or 1 unprovoked seizure + high recurrence risk (e.g., >60% over 10 yrs).
• ILAE 2017 Classification:
  • Focal Onset: Networks limited to one hemisphere.
    • Aware / Impaired Awareness.
    • Motor / Non-motor onset.
  • Generalized Onset: Bilaterally distributed networks.
    • Motor (e.g., Tonic-clonic, Atonic).
    • Non-motor (Absence).
  • Unknown Onset.

⭐ Simple febrile seizures do NOT increase risk of epilepsy. Complex febrile seizures do.

Etiology & Pathophysiology - Brainstorm Triggers

• Pathophysiology: ↑Excitatory (Glutamate) vs. ↓Inhibitory (GABA) neurotransmission.
• General Triggers:
  • Fever (children 6m-5y)
  • Sleep loss, stress
  • Metabolic: ↓Glucose, ↓Na+, ↓Ca2+
  • CNS Infections, Trauma, Hypoxia
  • Toxins, Drug withdrawal
  • Structural: Tumor, Stroke
  • Genetic factors
• Age-Specific:
  • Neonatal: HIE, ICH, Infection, Metabolic (Pyridoxine def.), IEM.
  • Infancy: Febrile seizures, Infection, Genetic (West, Dravet).
  • Childhood: Idiopathic, Infection, Trauma, Tumor. ⭐ > Pyridoxine (B6) deficiency: rare, treatable cause of neonatal/infant seizures. Trial IV pyridoxine 100mg.

Clinical Features & Diagnosis - Detective Workup

• History: Aura, LOC, motor features (type, duration), post-ictal state, triggers, FHx, developmental milestones.
• Examination: Neurocutaneous markers (e.g., ash-leaf spots), dysmorphism, focal neurological deficits.
• Key Investigations (1st unprovoked seizure):
  • EEG: Essential for classification & prognosis.
  • Neuroimaging (MRI preferred over CT): Indicated for focal seizures, abnormal neurological exam, or focal EEG findings.
  • Labs: Blood glucose, electrolytes (Ca, Mg, Na). Lumbar Puncture (LP) if CNS infection suspected (e.g., fever, meningismus).

⭐ Todd's paralysis: A postictal focal weakness (e.g., hemiparesis) that can last for minutes to 48 hours after a focal seizure, mimicking a stroke.

Management Principles - Taming the Storm

• Status Epilepticus (SE): 📌 BZDs → AEDs → Anesthesia!
  • 0-5 min: ABCs, IV access, Glucose.
  • 5-20 min (1st line): IV Lorazepam (0.1mg/kg), Diazepam (0.2mg/kg), IM Midazolam (0.2mg/kg).
  • 20-40 min (2nd line): IV Fosphenytoin (20mgPE/kg), Valproate (20-40mg/kg), Levetiracetam (30-60mg/kg), Phenobarbital (20mg/kg).
  • >40 min (Refractory SE): Anesthesia (Midazolam/Propofol).

• Epilepsy (Long-Term):
  • Goal: Monotherapy. Choice by seizure type.
  • Key AEDs:
    • Valproate (VPA): Broad; SE: Hepatotoxic, Teratogenic.
    • Levetiracetam (LEV): Broad; SE: Behavioral.
    • Ethosuximide (ESM): Absence.

⭐ Phenobarbital is often first-line for neonatal seizures.

Pediatric Epilepsy Syndromes - Kid-Specific Cases

⭐ Vigabatrin is first-line for infantile spasms in Tuberous Sclerosis.

High‑Yield Points - ⚡ Biggest Takeaways

• Febrile seizures: common; complex (focal, >15 min, recurrent in 24h) needs EEG/imaging.
• Infantile spasms: hypsarrhythmia on EEG; treat with ACTH or vigabatrin.
• Absence seizures: 3 Hz spike-wave on EEG; ethosuximide is first-line.
• Lennox-Gastaut syndrome: multiple seizure types, slow spike-wave EEG, intellectual disability.
• Status epilepticus: seizure >5 min; benzodiazepines first, then fosphenytoin/levetiracetam.
• JME: morning myoclonus, GTCs; valproate (caution: teratogenic).