Seizure Disorders and Epilepsy

Seizure Disorders and Epilepsy

Seizure Disorders and Epilepsy

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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. Focal vs. Generalized Seizure Brain Activity and EEG

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

Etiology & Pathophysiology - Brainstorm Triggers

  • Pathophysiology: ↑Excitatory (Glutamate) vs. ↓Inhibitory (GABA) neurotransmission. Glutamate and GABA Imbalance in Epilepsy
  • 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.

EEG: 3Hz spike-and-wave discharges in absence epilepsy

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

SyndromeAge OnsetSeizure TypesEEG PatternTx HighlightsPrognosis
West Syndrome3-12 moInfantile spasmsHypsarrhythmiaACTH, VigabatrinPoor
Lennox-Gastaut (LGS)1-8 yrMultiple (tonic, atonic, atypical absence)Slow spike-wave (<2.5 Hz)Valproate, ClobazamPoor
Childhood Absence (CAE)4-10 yrTypical absence3 Hz spike-waveEthosuximideGood
Benign Rolandic (BRE)3-13 yrNocturnal focal motor, oro-pharyngealCentrotemporal spikesOften none, LevetiracetamExcellent

⭐ 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).

Practice Questions: Seizure Disorders and Epilepsy

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Which of the following is true about febrile convulsions?

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Flashcards: Seizure Disorders and Epilepsy

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Infantile epileptic spasm occurs as an age-specific seizure disorder, before the age of _____

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Infantile epileptic spasm occurs as an age-specific seizure disorder, before the age of _____

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