Elsevier

The Lancet Neurology

Volume 13, Issue 8, August 2014, Pages 844-854
The Lancet Neurology

Personal View
The Glasgow Coma Scale at 40 years: standing the test of time

https://doi.org/10.1016/S1474-4422(14)70120-6Get rights and content

Summary

Since 1974, the Glasgow Coma Scale has provided a practical method for bedside assessment of impairment of conscious level, the clinical hallmark of acute brain injury. The scale was designed to be easy to use in clinical practice in general and specialist units and to replace previous ill-defined and inconsistent methods. 40 years later, the Glasgow Coma Scale has become an integral part of clinical practice and research worldwide. Findings using the scale have shown strong associations with those obtained by use of other early indices of severity and outcome. However, predictive statements should only be made in combination with other variables in a multivariate model. Individual patients are best described by the three components of the coma scale; whereas the derived total coma score should be used to characterise groups. Adherence to this principle and enhancement of the reliable practical use of the scale through continuing education of health professionals, standardisation across different settings, and consensus on methods to address confounders will maintain its role in clinical practice and research in the future.

Introduction

It is now difficult to envisage the chaos that characterised the assessment of patients with a head injury or other acute brain insult before the mid-1970s. Repeated observation of, what was termed at that time, conscious level was regarded as essential, but collection and exchange of data were undermined by ill-defined and inconsistent methods. Most investigators sought to divide the spectrum of altered consciousness into different constellations of discrete levels on the basis of terms such as comatose, sub-comatose, obtundation, stupor, semi-purposeful, and posturing. These terms now seem perplexingly vague and obscure. As a result, there were delays in detection of clinical changes,1 avoidable morbidity and mortality,2 and barriers to drawing reliable conclusions from research findings.

40 years ago, the description in The Lancet3 of what was later termed the Glasgow Coma Scale aimed to address the confusion resulting from these vague terms by proposing a practical approach, likely to be widely acceptable, through structured assessment of defined responses to stimuli. In this Personal View, we will examine the extent to which the original aspirations of the authors have been fulfilled, address some myths and misapprehensions, examine criticisms, and give our view of the continuing role of the scale in research and clinical practice. Although the scale has found wide application, our main focus is on its use in adults with traumatic brain injury, for whom most data are available.

Section snippets

Development and adoption of the scale

The rumour that the Glasgow Coma Scale was conceived in a bar in Glasgow is, sadly, not true.4 Its development began in 1971, as an instrument to improve the clinical care of people with acute brain injury and to increase understanding of the prognosis of those with severe brain damage.

The research that produced the scale took place in the Neurosurgical Unit at the Institute of Neurological Sciences in Glasgow, UK, a multidisciplinary clinical unit that provided specialist services in the west

Scaling, scoring, and classifying with the Glasgow Coma Scale

Soon after the description of the scale, each level of response was assigned a number—the worse the response, the lower the number. The steps in the eye opening, verbal response, and motor response subscales could then be communicated as three numbers (eg, E1, V2, M3, etc), allowing entry of clinical findings into a computer-based databank.11 The convenience of summing the separate scores into a single total score was soon recognised.17 This total score provided a useful overview for clinicians

Validity: relation to other indices and measures of severity

Without a gold standard for the evaluation of consciousness, the validity of the Glasgow Coma Scale as an indicator of severity is commonly obtained through the assessment of the relation between its score and other early clinical, functional metabolic, or structural features, and outcome (table 2,26, 27, 28, 29, 30, 31, 32, 33 figure 2, figure 3). Clinically, the duration of post-traumatic amnesia34 is a classic index for the severity of brain dysfunction after an injury, and lower values in

Reliability and confounders

After 40 years of use, and with the evolution of its applications, some investigators have had reservations and made critical comments about the Glasgow Coma Scale.50, 51, 52 When the Glasgow Coma Scale was devised the discipline of clinimetrics had not yet been developed.53 Subsequent systematic analyses54, 55, 56 yielded largely supportive conclusions about its composition and effectiveness, including its validation by acceptance.55 However, a consistent criticism has been variation in

Use of the Glasgow Coma Scale in clinical practice

Modern management of a patient with an acute brain injury is based on an anticipatory approach, aiming to identify and deal with sources of potential worsening rather than to react to adverse developments. For example, space-occupying haematomas should preferably be operated on before brainstem herniation occurs. Assessment of conscious level has a key role in clinical monitoring and in risk assessment for the presence of structural abnormalities. This is shown by the increasing yield of

Recommendations for use

The Glasgow Coma Scale assesses the level of consciousness in patients and should be distinguished from the overall coma score (numerical sum of the three components of the scale), which can be used for comparisons of groups. The scale is an effective instrument to monitor trends in level of consciousness. Ratings of the three individual components should be monitored, reported, and communicated separately (preferably in words but, with care, as a number). The displacement of graphical

Conclusions and future research

The Glasgow Coma Scale has evolved into a clinical instrument with several applications, including risk assessment, trend monitoring, classification, and prognosis. After 40 years, wide use of the scale supports its validation by acceptance55 and indicates that its creators have achieved many of their original aims. The Lancet article of 1974 was identified as a leading ‘citation classic’ in 2010.87, 88 An update in January, 2014, again using the Web of Science (appendix), showed a continuing

Search strategy and selection criteria

We identified articles through searches of PubMed, Science Direct, Ovid Medline, Embase, OVID, and CINAHL, with use of the search terms “Glasgow Coma Scale” or “Glasgow Coma Score” separately, and in combination with “review articles”. We included articles published up to Nov 1, 2013. We also identified papers from the authors' own files and from references cited in relevant articles. We generated the final reference list on the basis of articles' relevance to the topic of this Personal View.

References (91)

  • SM Green

    Cheerio laddie! Bidding farewell to the Glasgow Coma Scale

    Ann Emerg Med

    (2011)
  • K Prasad

    The Glasgow Coma Scale: a critical appraisal of its clinimetric properties

    J Clin Epidemiol

    (1996)
  • PM Middleton

    Practical use of the Glasgow Coma Scale; a comprehensive narrative review of GCS methodology

    Australas Emerg Nurs J

    (2012)
  • CM Clement et al.

    Clinical features of head injury patients presenting with a Glasgow Coma Scale Score of 15 and who require neurosurgical intervention

    Ann Emerg Med

    (2006)
  • D Simpson et al.

    Pediatric Coma Scale

    Lancet

    (1982)
  • S Galbraith

    Misdiagnosis and delayed diagnosis in traumatic intracranial haematoma

    BMJ

    (1976)
  • H Champion et al.

    Improving the Glasgow Coma Scale score: motor score alone is a better predictor

    J Trauma

    (2003)
  • L Mansuy et al.

    A clinical study of traumatic lesions in the brain stem

    Proc 3rd Int Congr Neurol Surg Excerpta Med Int Congr Ser

    (1966)
  • WF Bouzarth

    Neurosurgical watch sheet for craniocerebral trauma

    J Trauma

    (1968)
  • G Teasdale et al.

    Observer variability in assessing impaired consciousness and coma

    J Neurol Neurosurg Psychiatry

    (1978)
  • G Teasdale et al.

    Acute impairment of brain function-2. Observation record chart

    Nurs Times

    (1975)
  • B Jennett et al.

    Severe head injuries in three countries

    J Neurol Neurosurg Psychiatry

    (1977)
  • TW Langfitt

    Measuring the outcome from head injuries

    J Neurosurg

    (1978)
  • American College of Surgeons. Advanced Trauma Life Support....
  • GM Teasdale et al.

    A universal subarachnoid hemorrhage scale: report of a committee of the World Federation of Neurosurgical Societies

    J Neurol Neurosurg Psychiatry

    (1988)
  • O Bouamra et al.

    A new approach to outcome prediction in trauma: a comparison with the Triss model

    J Trauma

    (2006)
  • G Teasdale et al.

    Adding up the Glasgow Coma Score

    Acta Neurochir Suppl

    (1979)
  • LF Marshall et al.

    The National Traumatic Coma Data Bank. Part 1: design, purpose, goals, and results

    J Neurosurg

    (1983)
  • RW Rimel et al.

    Disability caused by minor head injury

    Neurosurgery

    (1981)
  • S Thornhill et al.

    Disability in young people and adults one year after head injury: prospective cohort study

    BMJ

    (2000)
  • RW Rimel et al.

    Moderate head injury: completing the clinical spectrum of brain trauma

    Neurosurgery

    (1982)
  • F Servadei et al.

    Defining acute mild head injury in adults: a proposal based on prognostic factors, diagnosis, and management

    J Neurotrauma

    (2001)
  • Predicting outcome after traumatic brain injury: practical prognostic models based on large cohort of international patients

    BMJ

    (2008)
  • EW Steyerberg et al.

    Predicting outcome after traumatic brain injury: development and international validation of prognostic scores based on admission characteristics

    PLoS Med

    (2008)
  • WD Obrist et al.

    Cerebral blood flow and metabolism in comatose patients with acute head injury

    J Neurosurg

    (1984)
  • JF Soustiel et al.

    Monitoring of cerebral blood flow and metabolism in traumatic brain injury

    J Neurotrauma

    (2005)
  • HM Wu et al.

    Selective metabolic reduction in gray matter acutely following human traumatic brain injury

    J Neurotrauma

    (2004)
  • RM Chesnut et al.

    Part 2: early indicators of prognosis in severe traumatic brain injury

    J Neurotrauma

    (2000)
  • P Goetz et al.

    Increase in apparent diffusion coefficient in normal appearing white matter following human traumatic brain injury correlates with injury severity

    J Neurotrauma

    (2004)
  • KW Lindsay et al.

    Evoked potentials in severe head injury–analysis and relation to outcome

    J Neurol Neurosurg Psychiatry

    (1981)
  • DO Okonkwo et al.

    GFAP-BDP as an acute diagnostic marker in traumatic brain injury: results from the prospective TRACK-TBI Study

    J Neurotrauma

    (2013)
  • CP Symonds

    Observations on the differential diagnosis and treatment of cerebral states consequent upon head injuries

    BMJ

    (1928)
  • TM McMillan et al.

    Assessment of post-traumatic amnesia after severe closed head injury: retrospective or prospective?

    J Neurol Neurosurg Psychiatry

    (1996)
  • M Bergsneider et al.

    Dissociation of cerebral glucose metabolism and level of consciousness during the period of metabolic depression following human traumatic brain injury

    J Neurotrauma

    (2000)
  • N Hattori et al.

    Correlation of regional metabolic rates of glucose with Glasgow Coma Scale after traumatic brain injury

    J Nucl Med

    (2003)
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