Closed Head Injury Clinical Presentation

Updated: Feb 24, 2016
  • Author: Leonardo Rangel-Castilla, MD; Chief Editor: Brian H Kopell, MD  more...
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Presentation

Physical

The Glasgow Coma Scale (GCS), first introduced by Teasdale and Jennett in 1974, has been the standard for objectively assessing individuals with traumatic head injuries (see Table 2). [38] It comprises motor, verbal, and eye scores. The overall score generally refers to the best response/examination obtained within the first 6-8 hours after injury and following resuscitation and is considered to be a predictor of the patient's overall outcome. [39, 40, 41, 13, 42]

The GCS has 2 main advantages in that it provides a reproducible, objective evaluation of neurological status, and it is a relatively simple way to monitor a patient's neurological condition over time. The GCS has shortcomings because its reliability depends on the absence of confounding factors (eg, sedation, paralytics, hypothermia, hypotension, hypoxia). Additionally, it cannot compensate for lack of eye opening in patients with periorbital trauma or loss of verbal response in intubated patients, and it omits brainstem reflex assessment. [43, 44]

Most clinicians assign a verbal score of 1 and apply the modifier "T" to intubated individuals. This may not be an accurate assessment of the patient's true verbal score. [45] The motor component of the GCS score is most predictive of the severity of the brain injury and correlates most strongly with overall outcome. [45]

The GCS score is often used to categorize the severity of head injury into mild (15-13), moderate (12-9), or severe (8 or less). In general, mild head injury does not usually involve significant primary brain injury, is not associated with neurological deficits, and may or may not include loss of consciousness. Approximately 75% of head injuries are categorized as mild to moderate in nature. [46] Most authorities agree that a patient with a severe head injury is one who is unconscious and unable to follow simple commands.

Table 2. Glasgow Coma Scale (Open Table in a new window)

Best Motor Response

Obeys commands

6

Localizes

5

Withdraws (abnormal flexion)

4

Flexion (decorticate posturing)

3

Extension (decerebrate posturing)

2

No response

1

Verbal Response

Oriented

5

Confused

4

Inappropriate words

3

Incomprehensible sounds

2

No response

1

Eye Opening

Spontaneous

4

To command

3

To pain

2

No response

1

Total

 

3-15

 

Patients should also be evaluated for basic brainstem reflexes. This assessment includes the evaluation of pupillary reflex, corneal reflex, gag/cough reflex, oculocephalic reflex, vestibuloocular reflex, and spontaneous breathing. Pupillary asymmetry or anisocoria of more than 1 mm (up to 1 mm may be physiological) must be attributed to an intracranial lesion until proven otherwise. [45]

Careful attention must be given to the evaluation of spontaneous breathing in the ventilated patient. A common pitfall is to mistakenly assess a patient as taking spontaneous breaths when the sensitivity on the ventilator is set to a level that triggers a mechanical breath at the slightest effort by the patient.

Proper evaluation entails setting the ventilator sensitivity to zero, then reevaluating the patient after a few seconds, which does not allow time for hypoxia or hypercapnia to develop. The presence of any of the above reflexes confirms that the patient has at least basic brainstem reflexes. A complete absence of brainstem reflexes is an ominous sign.

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Causes

Causes include the following:

  • Motor vehicle collisions

  • Motorcycle collisions

  • Assaults

  • Falls

  • Other

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