Traumatic Brain Injury: Diagnostic Tests

Obligatory medical device diagnostics.

  • Computed tomography of the skull (cranial CT, cranial CT, or cCT)-for evaluation of acute craniocerebral injury, in cases of high (intermediate) risk for intracranial injury (brain injury):
    • GCS (Glasgow Coma Scale) < 13, (GCS: 13-15); children: < 14.
    • Loss of consciousness > 5 min; (< 5 min).
    • Amnesia (form of memory impairment for temporal or content memories).
    • Multiple vomiting when there is a close temporal relationship to the exposure to violence
    • (Behavioral abnormality, persistent vomiting/headache).
    • Increasing disturbance of consciousness
    • (focal) neurological deficit
    • Seizure
    • Suspected CSF fistula (connection between the CSF system and the outside world).
    • Evidence of coagulopathy (e.g., anticoagulant treatment, non-sustained bleeding, laboratory findings, etc.)
    • Suspected impression (indentation)/skull base fracture; (linear skull fracture).
    • (head injury)
    • (severe accident mechanism: collision as a pedestrian or cyclist with motor vehicle; fall height > 5 steps or > 1 m).
    • (age < 1 year)

    Note: Intracranial hemorrhage may be delayed with anticoagulants; patients on DOAK therapy with blunt traumatic brain injury should have another cranial CT 12 hours after the accident.

  • Magnetic resonance imaging (MRI) of the skull (synonyms: cranial MRI; cMRI)-in pediatric traumatic brain injury (TBI)Note: Skull fractures occur with a frequency between 6% and 30% in children younger than two years of age who suffer a TBI.
  • Sonography of the calvaria (bony skull) and intracranial structures (transfontanellar or transcranial sonography)-in infantile traumatic brain injury (TBI); initially used to evaluate infants who do not offer clinical signs by the time of the examination

Canadian Computed Tomography Head Rule (CCHR).

Canadian CT rule for triage of patients with minimal head trauma:

Risk Criteria
High risk for neurosurgical intervention
  1. Glasgow Coma Scale score <15 at two hours.
  2. Suspicion of open or impression fracture of the skull
  3. Signs of a skull base fracture
  4. Vomiting two or more times
  5. Age ≥ 65 years
Intermediate risk, in CT for brain injury.
  1. Amnesia of 30 minutes or more before the event.
  2. Hazardous mechanism of injury (e.g., collision with a motor vehicle, fall from a height ≥ 90 cm or down more than five flights of stairs

The value of the CCHR is assured only for minor head trauma. By definition, these are those blunt head traumas associated with a Glasgow Coma Scale score of 13-15, a (brief) loss of consciousness, amnesia, or disorientation. According to a Münster study in patients with mild TBI, the indication for cCT was determined according to the CCHR and compared with the cCT results. RESULT: With a sensitivity of 98.9% and a specificity of 46.6%, all patients with neurosurgical intervention were detected by applying the main criteria of the CCHR. In addition, every patient with severe brain injury was detected by the extended criteria with a sensitivity of 99.6% and a specificity of 34.1%. This would have resulted in a reduction in the rate of cCT examinations of 45.1% for the main group and 22.1% for the extended criteria. No patient with severe brain injury would have been missed by using the criteria. Optional medical device diagnostics-depending on the results of the history, physical examination, laboratory diagnostics, and obligatory medical device diagnostics-for differential diagnostic clarification.

  • Computed tomography (CT) of the cervical spine (CT cervical spine) – if concomitant injury to the cervical spine is suspected.
  • Abdominal sonography (ultrasound examination of the abdominal organs) – if concomitant injury to the abdomen is suspected.
  • Computed tomography (CT) of the abdomen (abdominal CT) – on suspicion of concomitant injuries of abdomen.
  • Computed tomography of the thorax/chest (thoracic CT) – if concomitant injuries to abdomen are suspected.
  • Individual radiographs – depending on the pattern of injury.
  • Cranial pressure measurement
  • Encephalogram (EEG; recording of the electrical activity of the brain) – for seizures.

Other notes

  • In infantile traumatic brain injury (TBI), the prediction of skull fracture risk (risk of fracture of the skull) was 30.7% when the criteria “age less than two months” and “parietal or occipital hematoma” (bruise in the parietal and occipital regions) were combined. The sensitivity (percentage of diseased patients in whom the disease is detected by the use of the test, i.e., a positive test result occurs) of the two criteria reached 89% and the specificity (probability that actually healthy people who do not have the disease in question are also detected as healthy by the test) reached 87%.