Seizures: Overview and Classification

Definition

• Transient occurrence of signs and symptoms due to abnormally excessive or synchronous neuronal activity in the brain.

Types of Seizures

Based on Origin

• Generalized Seizures: Involves both hemispheres.
  • Previously known as primary generalized seizures.
• Focal Seizures: Originate from one hemisphere.
  • Can evolve to involve both hemispheres (called focal to bilateral seizures/secondary generalized seizures).

Based on Awareness (applies to Focal Seizures only)

• Focal Aware: Previously simple partial.
• Focal Impaired Awareness: Previously complex partial.

Based on Motor Involvement

• Motor Seizures: Involves movement.
  • Generalized: stiffening & jerking.
  • Focal: twitching, jerking, stiffening, automatic movements (e.g., licking lips, rubbing hands).
  • Jacksonian March: Abnormal movement spreads to other muscle groups.
• Non-Motor Seizures: No significant movement.
  • Generalized: Mostly absence seizures (changes in awareness).
  • Focal: Can involve other initial symptoms (e.g., changes in sensation, emotion, thinking).

Main Types of Generalized Seizures

1. Tonic-Clonic Seizures (Grand Mal)
   • Contraction of limbs, limb extension, arching of back.
   • Possible 'ignell cry'.
   • Total duration: 2-3 minutes.
2. Tonic Seizures
   • Increased tonicity, sustained contraction.
   • May cause cyanosis if breathing is affected.
3. Clonic Seizures
   • Characterized by shaking movements.
4. Myoclonic Seizures
   • Muscle spasms.
5. Absence Seizures (Petit Mal)
   • Little/no motor involvement.
   • Lasts around 10 seconds.
6. Atonic Seizures
   • Bilateral loss of muscle activity (more than 1 second).

Status Epilepticus

• Seizure lasting more than 5 minutes; medical emergency.
• Treatment: Airway management, medications (benzodiazepines, phenytoin, phenobarbital).

Post-ictal Phase

• Post-seizure period before returning to normal consciousness.
• Symptoms: confusion, tiredness, headaches, difficulty speaking.
• 10% may experience psychosis or amnesia.

Causes (Provoked vs. Unprovoked)

• Use 'VITAMINS' mnemonic:
  • Vascular (e.g., hemorrhagic stroke, hypertension).
  • Infections (e.g., meningitis, encephalitis).
  • Toxins (e.g., alcohol, cocaine, medications).
  • Arteriovenous malformations, Autoimmune conditions.
  • Metabolic (e.g., hypoglycemia, hyponatremia, multiple sclerosis).
  • Idiopathic.
  • Neoplasms (tumors).
  • Stress.

Diagnosis

• Witness history, postictal state, drug/alcohol history.
• Physical signs (e.g., tongue lesions, injuries during seizures).
• Investigations: Blood sugars, metabolic panels, CT/MRI, lumbar puncture (if infection suspected), EEG, prolactin levels.

Management

• Ensure safety: remove hazards, place in recovery position.
• First-line: Benzodiazepines (lorazepam, diazepam).
• Second-line: Barbiturates, propofol, phenytoin.
• Follow-up: Specialist clinics and anti-seizure medication (sodium valproate, lamotrigine, levetiracetam).