Glasgow Coma Scale (GCS): The Neurological Assessment Tool

About

The Glasgow Coma Scale was developed by Professors Graham Teasdale and Bryan Jennett. In the year 1974, these researchers at the University of Glasgow developed this tool.

This scale is widely used to measure consciousness of a person. It is mainly utilized when patients are in a coma or experiencing reduced consciousness. The scale assesses patients according to three aspects of responsiveness: eye-opening, motor, and verbal responses.

The Glasgow Coma Scale and its total score are now part of many guidelines and systems. It is primarily used for assessing people with serious injuries or illnesses.

Consciousness and the GCS Scoring System

In the medical context, consciousness means being awake, alert and oriented. This implies being responsive to the people around us and being able to understand what's happening in our immediate surroundings.

The Glasgow Coma Scale breaks down the assessment of functions into three parts:

• The best eye response (E)
• The best verbal response (V)
• The 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 Glasgow Coma Score thus has values between 3 and 15, three being the worst and score of 15 being the highest.

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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.

The GCS scoring is as follows:(1^✔ ✔Trusted Source
Glasgow Coma Scale (GCS)

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Test	1	2	3	4	5	6
Eye (ocular response)	Does not open eyes	Opens eyes in response to pain	Opens eyes in response to voice	Opens eyes spontaneously	N/A	N/A
Verbal (oral response)	Makes no sounds	Incomprehensible sounds	Inappropriate words	Confused and disoriented, but able to answer questions	Oriented to time, person, and place, converses normally	N/A
Motor (motoric response)	Makes no movements	Abnormal extension	Abnormal flexion	Flexion / Withdrawal from painful stimuli	Moves to localize pain	Obeys commands

GCS Assessment in Children

The Glasgow Coma Scale can be used in children older than 5 years without any modification. Younger children and infants are not able to comprehend or obey the commands to provide the necessary verbal and motor response.

A Pediatric Glasgow Coma Scale was initially described in Adelaide, which over the period of time has been universally accepted. On motor scale, this scale assesses the motor and eye response similar to that of adults. The verbal responses are assessed on a scale of 5-1. These responses are in the form of oriented replies, words, vocal sounds, cry and none(2^✔ ✔Trusted Source
Assessing the conscious level in infants and young children: a paediatric version of the Glasgow Coma Scale

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GCS: Its Implications and Uses

• The Glasgow Coma Scale helps guide the early care of patients with brain injuries or serious illnesses. It helps decide things like airway management, neuroimaging, whether to admit for observation, or discharge.
• Regular Glasgow Coma Scale assessments are important to track a patient's progress and guide treatment changes.
• The GCS Score categorizes traumatic brain injury as severe (GCS 3 to 8), moderate (GCS 9 to 12), and mild (GCS 13 to 15).
• The lower the GCS Score, the higher the risk of mortality after a head injury, showing a clear connection.
• The Glasgow Coma Scale Pupils Score (GCS-P) was described by Paul Brennan, Gordon Murray, and Graham Teasdale in 2018.

• Calculation of the GCS-P is by subtracting the Pupil Reactivity Score (PRS) from the Glasgow Coma Scale (GCS) total score: GCS-P = GCS – PRS.
• The Pupil Reactivity Score is calculated based on the non-reactivity of the pupils to light. Thus giving non reactivity of both pupils, one pupil and neither pupil a score of 2, 1 and 0(3^✔ ✔Trusted Source
  Glasgow Coma Scale
  
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GCS: Its Limitations

• The GCS scoring is a guiding assessment tool that helps with management. It's not the only factor determining a patient's prognosis or outcome.
• There are limitations to its use. It may not be possible to use the GCS all situations.For eg: When the patient is on a ventilator, is intoxicated, or is unable to hear/ see due to associated conditions.
• Factors like drug use, alcohol intoxication, shock, or low blood oxygen can alter a patient's level of consciousness. These factors could lead to an inaccurate score on the GCS(4^✔ ✔Trusted Source
  What Is the Glasgow Coma Scale?
  
  Go to source).

For the past 50 years, experts have carefully examined the scale and confirmed its ongoing value as a diagnostic tool. Further refinements and addition to the tool shall only add to the management strategies in critically ill patients.