On Call: Seizure

Basics

• Definition: A Sudden Uncontrolled Electrical Disturbance in the Brain
• Causes Changes in Behavior, Movement, Feelings, or Levels of Consciousness
• Affect 8-10% of Adults Over a Lifetime

Definitions

• Acute Symptomatic Seizure: Due to a Systemic Insult or Documented Brain Insult
• Unprovoked Seizure: Due to an Unknown Etiology
• Epilepsy: Any of the Following
  • ≥ Two Unprovoked Seizures > 24 Hours Apart
  • One Unprovoked Seizure with a Risk of Future Seizures Similar to the Recurrence Risk After Two Unprovoked Seizures Over the Next 10 Years
  • Diagnosis of an Epilepsy Syndrome

Types of Seizures

• Focal (Partial) Seizure: Involves a Localized Region of the Brain
  • Focal Seizure with Retained Awareness (Simple Partial Seizure)
  • Focal Seizure with Impaired Awareness (Complex Partial Seizure)
• Generalized Seizures: Involves the Entire Brain

Generalized Seizures

• Tonic-Clonic (Grand Mal) Seizures: An Abrupt Loss of Consciousness with Body Stiffening & Rhythmic Jerking Muscle Contraction
  • Most Common Generalized Seizure
  • Usually Last 1-3 Minutes
  • Risk for Tongue Biting During the Clonic Phase
• Clonic Seizure: Rhythmic Jerking Muscle Contraction
  • Usually Affect the Face, Neck, & Arms
• Tonic Seizure: Muscle Stiffening
  • Usually Affect the Back, Arms, & Legs
• Myoclonic Seizure: Sudden Brief Jerks of the Arms & Legs
• Atonic (Drop) Seizure: Sudden Loss of Muscle Control Causing Collapse or Falls
• Absence (Petit Mal) Seizure: Staring into Space or Subtle Body Movements (Blinking/Lip Smacking) with Impaired Consciousness
  • Generally Occur in Clusters
  • Last 5-10 Seconds But May Occur Over 100 Times Per Day
  • Most Common in Childhood

Postictal Phase/Period

• Definition: Period of Time After a Seizure Before Return to Baseline Level of Awareness & Function
• Manifestations:
  • Confusion
  • Impaired Awareness
  • Focal Neurologic Deficits (Todd Paralysis/Postictal Paresis)
    • Ex: Weakness of Hand, Arm or Leg
• Recovery:
  • Most Recover within 10-20 Minutes
  • Can Last Seconds-Hours
  • Confusion Can Last for Days-Weeks
• Prolonged Postictal Phase Should Be Evaluated for Subclinical Seizure Activity

Status Epilepticus

• Historical Definition:
  • Single Seizure > 30 Minutes, or
  • Series of Seizures without Complete Recovery Between Seizures Over a 30-Minute Period
• Modern Operational Definition:
  • ≥ 5 Minutes of Continuous Seizures, or
  • ≥ 2 Discrete Seizures without Complete Recovery Between Seizures

Causes of Acute Symptomatic Seizure

• Stroke
• Traumatic Brain Injury (TBI)
• Subdural Hematoma (SDH)/Subarachnoid Hemorrhage (SAH)
• Cerebral Venous Thrombosis
• Eclampsia
• Hypoxic-Ischemic Injury
• Meningitis or Encephalitis
• Brain Abscess
• Metabolic Derangements
  • Hypoglycemia
  • Hyperglycemia
  • Hyponatremia
  • Hypocalcemia
  • Hypomagnesemia
  • Uremia
  • Hyperthyroidism
• High Fevers
• Substance/Medication Withdrawal
  • Alcohol or Benzodiazepines Most Common
• Cocaine or Amphetamine Intoxication
• Intracranial Surgery