Head trauma (main)

This page is for adult patients. For pediatric patients, see: head trauma (peds)

Background

TBI epidemiology by GCS.

• Also known as Traumatic Brain Injury (TBI): Impairment in brain function from a mechanical force

TBI Pathophysiology

Primary injury

• Contusions
  • Bruises to brain parenchyma
• Hematomas
  • Epidural hematoma
  • Subdural hematoma
  • Intraparenchymal
  • Intraventricular
  • Subarachnoid hemorrhage
• Diffuse axonal injury
• Direct cellular damage
  • Neurons
  • Axons
• Tearing and shearing of tissues

Secondary injury

Brain swelling causes increased ICP which compresses the tissue causing ischemia with direct compression of the vasculature causing brain tissue herniation and brain death

• Leads to expansion of the original injury (predominantly metabolic insult)
  • Calcium and sodium shifts
  • Mitochondrial damage
  • Production of free radicals
• Ultimately leads to damage to axonal integrity and axonal transport
  • Enzyme activity leads to apoptosis
• Microscopic structural injury is often unidentifiable on CT or MRI

Cerebral Blood Flow and Autoregulation

• vasoconstriction
  • HTN, Hypocarbia, alkalosis
• No good way to measure cerebral blood flow
  • Use CPP as surrogate
    • CPP is amount of pressure needed to perfuse the brain
    • CPP=MAP-ICP
      • When ICP elevates, CPP decreases
      • Normal ICP
        • 15 in adults
        • <10 to 15 in children
        • 1.5 to 6.0 in infants
• Autoregulation allows the body to control the cerebral blood flow
  • Autoregulatory mechanism is damaged in most TBI patients

Clinical Features

• Adult patient with blunt head trauma

Differential Diagnosis

Head trauma

• Traumatic brain injury
  • Intracranial hemorrhage
    • Intra-axial
      • Traumatic intracerebral hemorrhage
    • Extra-axial
      • Epidural hemorrhage
      • Subdural hemorrhage
      • Subarachnoid hemorrhage
  • Moderate-to-severe traumatic brain injury
    • Elevated intracranial pressure
  • Mild traumatic brain injury
    • Clinical decision rules for head CT in trauma
    • Post-concussive syndrome
• Orbital trauma
• Maxillofacial trauma
• Scalp laceration
• Skull fracture
  • Basilar skull fracture
  • Skull fracture (peds)
• Pediatric head trauma
  • PECARN head trauma rule

Neck Trauma

• Penetrating neck trauma
• Blunt neck trauma
  • Vertebral and carotid artery dissection
  • Strangulation
  • Whiplash injury
• Cervical injury
  • Cervical fractures and dislocations
  • Cervical injury (peds)
  • Cervical spine clearance
• Neurogenic shock
• Spinal cord injury

Evaluation

Adult GCS

Eye Opening	Verbal	Motor
		6: Obeys commands
	5: Oriented	5: Localizes to pain
4: Spontaneously opens	4: Confused speech	4: Withdraws from pain (normal flexion)
3: Opens to command	3:Inappropriate words	3: Decorticate posturing (abnormal flexion)
2: Opens to pain	2: Incomprehensible sounds	2: Decerebrate posturing (extension)
1: Does not open	1: No response	1: No response

• 14-15: Mild
• 9-13: Moderate
• 3-8: Severe

Workup

Workup is dependent on GCS severity, see:

• Mild traumatic brain injury (GCS 14-15)
  • Clinical decision rules for head CT in trauma
• Moderate-to-severe traumatic brain injury (GCS <14)

Management & Disposition

Dependent on underlying diagnosis, see:

• Traumatic intracerebral hemorrhage
• Moderate-to-severe traumatic brain injury
  • Elevated intracranial pressure
• Mild traumatic brain injury
• Post-concussive syndrome

Calculators

Glasgow Coma Scale (GCS)

Glasgow Coma Scale Calculator

Component	Response	Points
Eye Opening (E)	Spontaneous	+4
	To verbal command	+3
	To pain	+2
	No eye opening	+1
Verbal Response (V)	Oriented	+5
	Confused	+4
	Inappropriate words	+3
	Incomprehensible sounds	+2
	No verbal response	+1
Motor Response (M)	Obeys commands	+6
	Localizes pain	+5
	Withdrawal from pain	+4
	Flexion to pain (decorticate)	+3
	Extension to pain (decerebrate)	+2
	No motor response	+1
GCS Score	/ 15

Interpretation

13–15	Mild brain injury
9–12	Moderate brain injury
3–8	Severe brain injury — consider intubation if unable to protect airway

References
Teasdale G, Jennett B. Assessment of coma and impaired consciousness. Lancet. 1974;2:81-84. PMID 4136544. Teasdale G et al. The Glasgow Coma Scale at 40 years. Lancet Neurol. 2014;13:844-854. PMID 25030516.

Canadian CT Head Rule

Canadian CT Head Rule

High Risk (for neurosurgical intervention)
Criteria	No	Yes
GCS <15 at 2 hours after injury	1
Suspected open or depressed skull fracture	1
Any sign of basal skull fracture (hemotympanum, raccoon eyes, CSF otorrhea/rhinorrhea, Battle sign)	1
Vomiting ≥2 episodes	1
Age ≥65 years	1
Medium Risk (for brain injury on CT)
Amnesia before impact >30 min	1
Dangerous mechanism (pedestrian struck, occupant ejected, fall from ≥3 feet or ≥5 stairs)	1
High Risk Criteria	/ 5
Medium Risk Criteria	/ 2

Interpretation
All No	CT NOT required — Low risk for clinically important brain injury. Safe for discharge with head injury instructions.
Medium risk ≥1	CT recommended — Risk of brain injury on CT. Imaging indicated.
High risk ≥1	CT required — High risk for neurosurgical intervention. Urgent CT head.

References

Stiell IG, Wells GA, Vandemheen K, et al. The Canadian CT Head Rule for patients with minor head injury. Lancet. 2001;357(9266):1391-1396. PMID 11356436. Stiell IG, Clement CM, Rowe BH, et al. Comparison of the Canadian CT Head Rule and the New Orleans Criteria in patients with minor head injury. JAMA. 2005;294(12):1511-1518. PMID 16189364. Inclusion criteria: GCS 13-15, age ≥16, injury within 24 hours, witnessed LOC/amnesia/disorientation.

See Also

• Pediatric head trauma
• Coup contrecoup injury