Procedure

Electroencephalogram

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Electroencephalogram, EEG

  • Background
  1. Measures electrical activity of cerebral cortex
  2. Measures gray matter function (Neuronal function)
  3. Normal in white matter disease
  • Seizure Disorder findings
  1. Indications
    1. Seizure Diagnosis
    2. Anticonvulsant weaning
      1. Seizure free for 2 years and
      2. Normal EEG
  2. Non-Seizure Times
    1. Abnormal in 70% of Seizure patients
  3. During Seizure
    1. Massive electrical discharge
  4. Post-ictal
    1. Slowing of EEG
  5. Medications that do not affect EEG
    1. Anticonvulsants
  6. Medications that cause Beta (fast wave patterns)
    1. Barbiturates
    2. Benzodiazepines
  • Cerebrovascular Accident (CVA) assessment
  1. Cortical CVA (large vessel disease)
    1. Abnormal EEG
  2. Subcortical or Brainstem CVA (small vessels disease)
    1. Normal EEG
  • Metabolic encephalopathy
  1. Non-focal slowing of EEG
  2. Rhythmic bursts of symmetrical frontal slowing
  3. Specific patterns may assist with etiology
    1. Hepatic Encephalopathy: Triphasic waves