II. Signs

  1. Alternating hyperpnea and apnea at regular intervals (30 second to 2 minute cycles)
  2. Smooth waxing and waning in depth of respiration

III. Pathophysiology

  1. Sites of Injury
    1. Bilateral Cerebral Hemisphere dysfunction or
    2. Diencephalon dysfunction (posterior forebrain structures including the Thalamus)
  2. Mechanism
    1. See Respiratory Physiology
    2. Hyperventilation with rapid and deep breathing results in hypocapnia (decreased pCO2)
    3. Decreased pCO2 suppresses respiration resulting in brief apnea
    4. Apnea results in rise in CO2 again, allowing for Hyperventilation and the cycle repeats itself

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