Seizure

Seizure

David Ray Velez, MD

Table of Contents

Definition
Causes
Evaluation
Treatment

Definition

Seizure: A Sudden Uncontrolled Electrical Disturbance in the Brain

Types of Seizures

  • Provoked:
    • Provoked Seizure: Due to a Systemic Insult or Documented Brain Insult
    • Unprovoked Seizure: Due to an Unknown Etiology
  • Localization:
    • 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

Types of Generalized Seizures

  • Tonic-Clonic (Grand Mal) Seizures: An Abrupt Loss of Consciousness with Body Stiffening and Rhythmic Jerking Muscle Contraction
    • The Most Common Generalized Seizure
    • Usually Last 1-3 Minutes
    • Risk for Tongue Biting During the Clonic Phase
  • Tonic Seizure: Muscle Stiffening
    • Usually Affect the Back, Arms, and Legs
  • Clonic Seizure: Rhythmic Jerking Muscle Contraction
    • Usually Affect the Face, Neck, and Arms
  • Myoclonic Seizure: Sudden Brief Jerks of the Arms and 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 Occurs in Clusters
    • Last 5-10 Seconds but May Occur Over 100 Times Per Day
    • Most Common in Childhood

Postictal Phase/Period

  • Definition: The Period of Time After a Seizure Before Return to Baseline Level of Awareness and Function
  • Manifestations:
    • Confusion
    • Focal Neurologic Deficits (Todd Paralysis/Postictal Paresis)
      • Ex: Weakness of Hand, Arm or Leg
    • Impaired Awareness
  • 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 by EEG

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

Epilepsy

  • Definition: 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

Causes

Causes

  • 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
  • Sepsis
  • Substance/Medication Withdrawal
    • Alcohol or Benzodiazepines are Most Common
  • Cocaine or Amphetamine Intoxication
  • Intracranial Surgery
  • Sleep Deprivation

Evaluation

Examination

  • Always Start with ABC’s and Vital Signs
    • May Require Intubation and Mechanical Ventilation
  • Evaluate for Possible Seizure Precipitants or Triggers
  • Neurologic Exam to Evaluate for Focal or Lateralizing Defects

Work Up

  • Labs (CBC, Glucose, Electrolytes/Renal Panel)
  • Consider Urinalysis or Toxicology Screen
  • EKG
  • Electroencephalography (EEG)
    • Demonstrates Focal or Generalized Epileptiform Discharges
    • Consider Urgent EEG to Monitor for Subclinical Seizures if Postictal and Not at Baseline within 30-60 Minutes
  • Neuroimaging (CT or MRI)
  • Consider Lumbar Puncture if Presentation is Highly Suggestive of Meningitis

Treatment

Acute Seizure Control

  • Primarily Managed by Benzodiazepines
  • Agents:
    • Lorazepam (Ativan) 0.1 mg/kg (Max 2 mg/min)
      • Generally Preferred for Rapid Onset with the Highest Success
    • Diazepam (Valium) 0.15 mg/kg (Max 5 mg/min)
    • IM Midazolam 10 mg
  • Out-of-Hospital Benzodiazepine Use is Associated with Shorter Duration of Status Epilepticus and Lower Rates of Respiratory Complications – No Change in Ultimate Neurologic Deficits at Discharge
  • Give a Second Dose After 5-10 Minutes if Not Resolved

Refractory Status Epilepticus

  • Midazolam Infusion
  • Propofol Infusion
  • Phenobarbital Infusion

Correct Any Underlying Cause or Metabolic Derangement

Consider Further Antiseizure Prophylaxis

  • Levetiracetam (Keppra)
  • Phenytoin (Dilantin)
  • Fosphenytoin (Cerebyx)