The Glasgow Coma Scale (also called the Glasgow Coma Score) was originally developed in 1974 by two neurosurgeons at the University of Glasgow. It measures a person’s responsiveness to stimuli and is used to assess level of consciousness with a score ranging from 3 (near death) to 15 (completely conscious). The original test used a maximum score of 14 but was later modified; therefore, the test commonly used today is technically the Modified Glasgow Coma Scale.
Physicians use the test not only for assessing consciousness at a given moment, but also for determining whether a patient is improving or declining by comparing scores over a period of time.
How the Glasgow Coma Scale Works
The test has three parts with different scores assigned to each. A score is recorded for the highest level of response in each test, and the total of the three scores determines the result.
- Eye Response (score of 1 to 4)
- Verbal Response (score of 1 to 5)
- Motor Response (score of 1 to 6)
4 = Eyes open spontaneously without requiring stimulation
3 = Eyes open in response to voice (does not apply to awakening a sleeping patient)
2 = Eyes open in response to pain (usually applied by pinching the fingernail)
1 = Eyes do not open
5 = Responds coherently when asked questions (name, age, day and month, etc.)
4 = Speaks coherently but exhibits confusion or disorientation
3 = Speaks random words or thoughts, or doesn’t respond coherently to questions
2 = Makes sounds but not understandable words
1 = Makes no sounds
6 = Can perform simple movements when asked
5 = Responds to pain or pressure being applied by trying to reach for or remove the source
4 = Attempts to pull away or turn away when pain or pressure is applied
3 = Responds to pain by bringing forearms to the chest and clenching fists
2 = Responds to pain by rigidly extending arms, arching head back, and/or extending the legs and toes
1 = Does not respond to pain
What the Glasgow Coma Scale Score Means
Adding the scores from each of the three tests yields the Glasgow Coma Scale score, which can indicate the severity of a traumatic brain injury.
15 – 13: Mild injury with good prognosis for recovery. Some symptoms (emotional, mild cognitive impairment, headaches) may persist for an extended period. (See Understanding Post-Concussion Syndrome.)
12 – 9: Moderate injury with probable lasting cognitive disability that can benefit from rehabilitation.
8 – 3: Comatose. Survivors are likely to have severe physical and mental disabilities.
Limitations in Using the Glasgow Coma Scale
Because younger children may have limited verbal capabilities, the Glasgow Coma Scale is primarily used for older children and adults. Younger patients are evaluated with the Pediatric Glasgow Coma Scale, a slightly different test.
When other injuries or medical interventions interfere with the patient’s ability to open his eyes (eye injuries or bandages), speak (facial injury or breathing tube), or move (injury to limbs), physicians record the individual scores for only the testable responses. Obviously, the total will not fit the evaluation criteria above. In these cases, it is up to the physician to interpret the partial score.
- Concussion Symptoms
- MRI vs. CT Scan in Determining Brain Injuries
- PET and SPECT Scans of Brain Function
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