Glasgow coma scale

# Overview
The Glasgow Coma Scale or GCS is a neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment. A patient is assessed against the criteria of the scale, and the resulting points give a patient score between 3 (indicating deep unconsciousness) and either 14 (original scale) or 15 (the more widely used modified or revised scale). GCS was initially used to assess level of consciousness after head injury, and the scale is now used by first aid, emergency medical services, and doctors as being applicable to all acute medical and trauma patients. In hospitals it is also used in monitoring chronic patients in the intensive care. The scale was published in 1974 by Graham Teasdale and Bryan J. Jennett, professors of neurosurgery at the University of Glasgow's Institute of Neurological Sciences at the city's Southern General Hospital.

# Glasgow Coma Scale
The Glasgow Coma Scale or GCS is a neurological scale that aims to give a reliable, objective way of recording the conscious state of a person for initial as well as subsequent assessment. A patient is assessed against the criteria of the scale, and the resulting points give a patient score between 3 (indicating deep unconsciousness) and either 14 (original scale) or 15 (the more widely used modified or revised scale). GCS was initially used to assess level of consciousness after head injury, and the scale is now used by first aid, emergency medical services, and doctors as being applicable to all acute medical and trauma patients. In hospitals it is also used in monitoring chronic patients in the intensive care. The scale was published in 1974 by Graham Teasdale and Bryan J. Jennett, professors of neurosurgery at the University of Glasgow's Institute of Neurological Sciences at the city's Southern General Hospital.

# Glasgow Coma Scale Calculator
The scale is composed of three tests: eye, verbal and motor responses. The three values separately, as well as their sum, are considered. The lowest possible GCS (the sum) is 3 (deep coma or death), while the highest is 15 (fully awake person).

# Interpretation
Individual elements, as well as the sum of the score, are important.  Hence, the score is expressed in the form "GCS 9 = E2 V4 M3 at 07:35". Generally, when a patient is in a decline of their GCS score, the nurse or medical staff should assess the cranial nerves and determine which of the twelve have been affected. Tracheal intubation and severe facial/eye swelling or damage make it impossible to test the verbal and eye responses. In these circumstances, the score is given as 1 with a modifier attached e.g. "E1c" where "c" = closed, or "V1t" where t = tube. A composite might be "GCS 5tc". This would mean, for example, eyes closed because of swelling = 1, intubated = 1, leaving a motor score of 3 for "abnormal flexion". Often the 1 is left out, so the scale reads Ec or Vt.
Brain injury is classified as:
- GCS 8-15 and somnolence: Sleepy, easy to wake
- GCS 8-15 and stupor: Hypnoid, hard to wake
- GCS  13: Mild Head Injury
- GCS 912: Moderate Head Injury
- GCS  8: Severe Head Injury
- GCS 7-8: Light coma; Coma Grade I
- GCS 5-6: Light coma; Coma Grade II
- GCS 4: Deep coma; Coma Grade III
- GCS 3: Deep coma; Coma Grade IV
The GCS has limited applicability to children, especially below the age of 36 months (where the verbal performance of even a healthy child would be expected to be poor). Consequently, the Pediatric Glasgow Coma Scale, a separate yet closely related scale, was developed for assessing young children.

# Disclaimer
Based on motor responsiveness, verbal performance, and eye opening to appropriate stimuli, the Glasgow Coma Scale was designed and should be used to assess the depth and duration of coma and impaired consciousness. This scale helps to gauge the impact of a wide variety of conditions such as acute brain damage due to traumatic and/or vascular injuries or infections, metabolic disorders (e.g., hepatic or renal failure, hypoglycemia, diabetic ketosis) etc.

# Revisions
- Glasgow Coma Scale: While the 15-point scale is the predominant one in use, this is, in fact, a modification and is more correctly referred to as the Modified Glasgow Coma Scale. The original scale was a 14 point scale, omitting the category of "abnormal flexion". Some centers still use this older scale, but most (including the Glasgow unit where the original work was done) have adopted the modified one.
- The Rappaport Coma/Near Coma Scale made other changes
- Meredith W., Rutledge R, Fakhry SM, EMery S, Kromhout-Schiro S have proposed calculating the verbal score based on the measurable eye and motor responses.

# Controversy
The GCS has come under pressure from some researchers that take issue with the scale's issues, such as poor inter-rater reliability and lack of prognostic utility. Although there is not an agreed upon alternative, newer scores such as the Simplified Motor Scale and FOUR Score have also been developed as improvements to the GCS. While inter-rater reliability of these newer scores have been slightly higher than the GCS, they were not significant enough to gain consensus as a replacement.