Glasgow Coma Scale Score Calculation and Clinical Significance

Components and Scoring of the Glasgow Coma Scale

The Glasgow Coma Scale consists of three components that assess eye opening, verbal response, and motor response, with each component scored separately to give a total GCS score, as recommended by the American Academy of Neurology 2, 1
Eye Response: Opens eyes to pain = 2 points, which is a critical component of the GCS score 1
Verbal Response: Making incomprehensible sounds = 2 points, indicating a severe impairment in verbal communication 1
Motor Response: Withdraws arm to pain = 4 points, which is a key indicator of motor function 1

A GCS score of 8 classifies the patient as having severe traumatic brain injury, according to the Brain Injury Association of America 3
GCS scores are categorized as: Mild (13-15), Moderate (9-12), and Severe (≤8), as defined by the World Health Organization 3
The GCS was developed by Teasdale and Jennett in 1974 as a standardized tool for assessing consciousness level in patients with head injury, and is widely used by the American College of Surgeons 2
A GCS score of 8 or less typically indicates the need for airway protection and possible neurosurgical intervention, as recommended by the Neurocritical Care Society 3, 2

While a single GCS score provides valuable information, serial GCS determinations are more valuable for detecting deterioration in patients with head injuries, as emphasized by the American Academy of Emergency Medicine 2
Failing to assess each component separately before calculating the total score is a common pitfall in GCS assessment, which can be avoided by following the guidelines set by the American College of Emergency Physicians 2
Not accounting for confounding factors like alcohol intoxication, sedative medications, or metabolic disturbances is another common pitfall, as noted by the Society of Critical Care Medicine 1
Using a single GCS score rather than serial assessments to monitor trends can lead to inaccurate conclusions, as warned by the American College of Surgeons 2, 4