Health Questions and Answers

Coma

What are the most common causes of coma?

  • Drugs (e.g., alcohol, illicit drugs, accidental or intentional overdose)
  • Hypoxia
  • Hypoglycemia
  • Other metabolic derangements (e.g., sepsis, uremia, hepatic failure)
  • Structural brain disease (e.g., stroke, intracranial hemorrhage)

Outline the approach to the patient in coma.

  • ABCs-protect the airway, breathing, and circulation.
  • Draw blood to check for metabolic derangements, infections, and drugs.
  • Infuse glucose, thiamine, and naloxone.
  • History and physical exam for clues to the cause of coma. Focus on pupils and extraocular movements for evidence of brain-stem dysfunction.
  • Definitive diagnosis (and therapy) may require CT scanning, lumbar puncture, EEG, and other studies, depending on the situation.
  • KEY POINTS:
  1. The most common cause of dizziness is benign paroxysmal positional vertigo.
  2. The leading causes of death after a stroke are medical complications, not the stroke itself.
  3. Although heparin may prevent some future strokes, it has no value in the acute treatment of strokes.
  4. The sudden onset of a severe headache may be an intracranial hemorrhage.
  5. Despite a long differential, it is rare to find a treatable cause of dementia.
  6. Most etiologies of coma are medical problems, not primary neurologic diseases.

What is the prognosis of coma?
Almost 70% of patients admitted to a hospital in a coma die. Brain-stem abnormalities-absent extraocular movements, gag reflex, or spontaneous respirations, or unreactive pupils-carry an especially grim prognosis.

References
WEB SITES
www.neuroguide.com
www.aan.com (American Academy of Neurology)
www.medmatrix.org
www.internets.com/mednets/sneurolo.htm
www.medwebplus.com/subject/Neurology.html

BIBLIOGRAPHY

  • Hamel MB et al: Identification of comatose patients at high risk for death or severe disability. JAMA 273:1742-1484, 1995.
  • Aminoff M: Neurology and General Medicine, 3rd ed. Philadelphia, Churchill-Livingstone, 2001.
  • Noseworthy JH (ed): Neurologic Therapeutics. London, Martin Dunitz, 2003.
  • Bradley WG, Daroff RB, Fenichel GM, Jankovic J: Neurology in Clinical Practice, 4th ed. Philadelphia, Butterworth-Heinemann, 2004.
  • Caplan LR: Stroke: A Clinical Approach, 3rd ed. New York, Butterworth-Heinemann, 2000.
  • Samuels MA, Feske S (eds): Office Practice of Neurology, 2nd ed. Boston, Churchill-Livingstone, 2003.
  • Johnson RT, Griffin JW: Current Therapy in Neurologic Disease, 6th ed. St. Louis, Mosby, 2002.
  • Victor M, Ropper AH: Prinicples of Neurology, 7th ed. New York, McGraw-Hill, 2001.

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