The Glasgow Coma Scale was first published in 1974 at the University of Glasgow by neurosurgery professors Graham Teasdale and Bryan Jennett. The Glasgow Coma Scale (GCS) is used to objectively describe the extent of impaired consciousness in all types of acute medical and trauma patients. The scale assesses patients according to three aspects of responsiveness: eye-opening, motor, and verbal responses. Reporting each of these separately provides a clear, communicable picture of a patient’s state.[rx]
Function
Scoring and Parameters
The Glasgow Coma Scale divides into three parameters: best eye response (E), best verbal response (V) and best motor response (M). The levels of response in the components of the Glasgow Coma Scale are ‘scored’ from 1, for no response, up to normal values of 4 (Eye-opening response) 5 ( Verbal response) and 6 (Motor response) The total Coma Score thus has values between three and 15, three being the worst and 15 being the highest.
The score is the sum of the scores as well as the individual elements. For example, a score of 10 might be expressed as GCS10 = E3V4M3.
Best eye response (4)
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No eye-opening
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Eye-opening to pain
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Eye-opening to sound
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Eyes open spontaneously
Best verbal response (5)
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No verbal response
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Incomprehensible sounds
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Inappropriate words
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Orientated
Best motor response (6)
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No motor response.
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Abnormal extension to pain
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Abnormal flexion to pain
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Withdrawal from pain
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Localizing pain
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Obeys commands
Application of the Glasgow Coma Scale in Pediatrics
The Glasgow Coma Scale can be used in children older than 5 years with no modification. Younger children and infants are not able to provide the necessary verbal responses for the practitioner to use the scale to assess their orientation or obey the commands to evaluate their motor response. Since a Pediatric Glasgow Coma Scale was initially described in Adelaide, there have been several modifications without any particular one becoming universally accepted.[rx] The versions below derive from those of James and the Pediatric Emergency Care Applied Research Network[rx][rx]
Children less than 2 years old (pre-verbal) / Children greater than 2 years old (verbal)
Best eye response
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No eye opening / 1 No eye-opening
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Eye-opening to pain / 2 Eye-opening to pain
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Eye-opening to sound / 3 Eye-opening to sound
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Eyes open spontaneously / 4 Eyes open spontaneously
Best verbal response
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None / 1 None
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Moans in response to pain / 2 Incomprehensible sounds
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Cries in response to pain / 3 Incomprehensible words
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Irritable/cries / 4 Confused
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Coos and babbles / 5 Orientated – appropriate
Best motor response
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No motor response / 1 No motor response.
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Abnormal extension to pain / 2 Abnormal extension to pain
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Abnormal flexion to pain / 3 Abnormal flexion to pain
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Withdrawal to pain / 4 Withdrawal to pain
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Withdraws to touch / 5 Localises to pain
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Moves spontaneously and purposefully / 6 Obeys commands
Issues of Concern
The following factors may interfere with the Glasgow Coma Scale assessment
Pre-existing factors
- Language barriers
- Intellectual or neurological deficit
- Hearing loss or speech impediment
Effects of current treatment
- Physical (e.g., intubation): If a patient is intubated and unable to speak, they are evaluated only on the motor and eye-opening response and the suffix T is added to their score to indicate intubation.
- Pharmacological (e.g., sedation) or paralysis: If possible, the clinician should obtain the score before sedating the patient.
Effects of other injuries or lesions
- Orbital/cranial fracture
- Spinal cord damage
- Hypoxic-ischemic encephalopathy after cold exposure
There are instances when the Glasgow Coma Scale is unobtainable despite efforts to overcome the issues listed above. It is essential that the total score is not reported without testing and including all of the components because the score will be low and could cause confusion.
Glasgow Coma Scale Pupils Score
The Glasgow Coma Scale Pupils Score (GCS-P) was described by Paul Brennan, Gordon Murray, and Graham Teasdale in 2018 as a strategy to combine the two key indicators of the severity of traumatic brain injury into a single simple index.[rx][rx]
Calculation of the GCS-P is by subtracting the Pupil Reactivity Score (PRS) from the Glasgow Coma Scale (GCS) total score:
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GCS-P = GCS – PRS
The Pupil Reactivity Score is calculated as follows.
Pupils unreactive to light – Pupil Reactivity Score
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Both pupils – 2
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One pupil – 1
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Neither pupil – 0
The GCS-P score can range from 1 and 15 and extends the range over which early severity can be shown to relate to outcomes of either mortality or independent recovery.
Classification of Severity of TBI
The relationship between the GCS Score and outcome l is the basis for a common classification of acute traumatic brain injury:
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Severe, GCS 3 to 8
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Moderate, GCS 9 to 12
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Mild, GCS 13 to 15
With the GCS-P score values between one and 8 denote a severe injury.