Glasgow Coma Scale

Traumatic brain injury can alter a person's conscious state. To asses a person's conscious state following brain injury, doctors use a number of systems and tests. One widely used system is the Glasgow Coma Scale (GCS). The Glasgow Coma scale evaluates a person's level of consciousness and degree of brain injury. The scale standardizes consciousness assessment and helps doctors predict patient prognosis. The Glasgow Coma Scale was first published in 1974 (Teasdale G, Jennett B. Assessment of coma and impaired consciousness. A practical scale. Lancet 1974,2:81-84. ) by Graham Teasdale and Bryan J. Jennett, two Glasgow University neurology professors. The Glasgow Coma Scale evaluates visual, motor, and verbal responses to stimuli from three categories. Each response - or lack there of - by the patient is scored. The score from each category is added and assessed. The total Glasgow Coma Scale score helps doctors identify a person's conscious state and extent of brain injury. A lower score indicates more severe brain injury and poorer prognosis.

*Glasgow Coma Scale Scoring

Best Eye Response (4)

  1. No eye opening.
  2. Eye opening to pain.
  3. Eye opening to verbal command.
  4. Eyes open spontaneously.

Best Verbal Response (5)

  1. No verbal response
  2. Incomprehensible sounds.
  3. Inappropriate words.
  4. Confused
  5. Orientated

Best Motor Response (6)

  1. No motor response.
  2. Extension to pain.
  3. Flexion to pain.
  4. Withdrawal from pain.
  5. Localizing pain.
  6. Obeys Commands.

Mild (13-15):

Moderate Disability (9-12):

  • Loss of consciousness greater than 30 minutes
  • Physical or cognitive impairments which may or may not resolve
  • Benefit from Rehabilitation

Severe Disability (3-8):

  • Coma: unconscious state. No meaningful response, no voluntary activities

Vegetative State (Less Than 3):

  • Sleep wake cycles
  • Arousal, but no interaction with environment
  • No localized response to pain

Persistent Vegetative State:

  • Vegetative state lasting longer than one month

Brain Death:

  • No brain function
  • Specific criteria needed for making this diagnosis

The scale may not be useful for brain injury victims with special conditions that limit his or her ability to respond. An endotracheal tube or breathing apparatus can inhibit the patient's verbal response score. Low blood oxygen (hypoxemia), drug overdose, intoxication, or other metabolic disturbances can also interfere with the scoring. Spinal cord injury impairs motor skills and affects scoring for the "Best Motor Response" category. In spite of these special circumstances, the Glasgow Coma Scale remains one of the most widely used systems in hospitals today.

Another well-known and widely used system is the Rancho Los Amigos Coma Scale. Please read further to learn about this system.

To learn more about traumatic brain injury and how it is caused, diagnosed, and treated, please read other articles on this site.

[Last revision: July 2009]

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