Seizures and Epilepsy - Lecture Notes

Key Definitions

• Seizures vs. Epilepsy
  • Not all seizure occurrences classify as epilepsy.
  • Epilepsy: Two or more unprovoked seizures.
  • Provoked Seizures: Result from known causes like drug interactions, overdoses, or metabolic changes.
  • Unprovoked Seizures: No identifiable cause.

Seizure Classification

• Two broad categories: Generalized and Focal.
  • Focus of this lecture: Generalized Seizures.

Generalized Seizures

• Definition: Temporary involuntary change caused by abnormal/excessive cortical neuron activity.
  • Affects the entire brain.
  • Results in unconsciousness.

Common Types of Generalized Seizures

1. Tonic-Clonic Seizures (formerly Grand Mal)*

   • Characteristics:
     • Initial cry due to body contraction and air escape.
     • Individual becomes unconscious, falls.
     • Rhythmic contraction (tonic) and relaxation (clonic) of muscles.
     • Breathing stops, potentially turning the individual blue.
     • Duration: Usually 2-3 minutes; if >5 minutes, termed status epilepticus.

2. Absence Seizures (formerly Petit Mal)

   • Characteristics:
     • Sudden stop in activity, blank stare, look into the distance.
     • Minimal/no muscular contraction.
     • Brief unconsciousness, appears like daydreaming.
     • Duration: Typically 20-30 seconds.
     • Frequency: Can occur 70-100 times/day.
     • More common in children.

Less Common Types of Generalized Seizures

• Clonic Seizure: Rhythmic contraction and relaxation.
• Tonic Seizure: Prolonged muscle contraction.
• Myoclonic Seizure: Quick, singular muscle group contraction.
• Atonic Seizure: Loss of muscle tone, individual may fall.

Prevalence in Demographics

• More common in children than adults.
• 10% of infants experience at least one seizure, often febrile.

Future Topics

• Discussion on partial/focal seizures and treatments.