Definition
- WHO defines TBI as an acute injury to the brain resulting from mechanical energy to the head from external physical force excluding injuries relating to illicit drug, alcohol, or substance, medication, or caused by other treatment or injuries
- TBI has replaced the old term ‘head injury’ as it captures the importance of the brain injury
Numbers
- Incidence:
- 262-790 cases per 100 000 people annually (Peeters et al., 2015, Feigin et al., 2013 )
- Prevalence
- Adults:
- 12% had experienced a TBI with loss of consciousness
- Male twice as much risk as female.
- Paediatric (McKinlay et al., 2008)
- Higher risk
- > 30% of people had experienced at least one TBI before they are 25 years of age
- Mortality
- 10.5–11.7/100 000 population in Europe (Peeters et al., 2015)
- TBI patients have been found to have a substantially elevated long- term risk for premature mortality due to
- Suicide
- Subsequent injuries
- Assaults
- Reduced average life expectancy of nine years following inpatient rehabilitation for TBI
- Annual mortality remains increased, up to sevenfold, for at least 13 years (McMillan et al., 2011).
- 56–60% of patients with GCS score ≤8 have 1 or more other organ system injured.
- 25% have “surgical” lesions.
- 4–5% incidence of associated spine fractures with significant head injury (mostly C1 to C3).
- Pandrich 2020 et al
- If you have a TBI there is a 6.5% chance of finding a C spine injury
- If you have a TBI there is a 12.5% chance of finding a spine injury
- If you have a C spine injury there is a 40% chance of TBI
- If you have a spine injury there is 32.5% chance of a TBI
- Remember: the loss of consciousness may have preceded (and possibly have caused) the trauma.
- Maintain an index of suspicion for e.g. aneurysmal SAH, hypoglycemia, etc. in the differential diagnosis of the causes of trauma and associated coma.
- TBI is associated with extracranial injuries in about 35% of cases
- European epidemiological studies that calculated a TBI severity ratio
- 22 mild TBI: 1.5 moderate TBI: 1 severe TBI (i.e. 90% of TBI is mild).
- RR of a second TBI among those with an earlier TBI was 2.8-3 times greater than the non-injured sample.
Aetiology
- Main causes of TBI
- Road traffic incidents (44–80%)
- Fallsᵃ (12–55%)
- Violenceᵇ (7–17%) — Fire arm (>50% suicide) (Aarabi et al., 2001)
- Work and sports (4%)
- Others
- Notes
- ᵃMore recently, the leading cause in northern Europe, United States, and Australia specially in young children and elderly (>75-year-old).
- ᵇHigher risk population: male, young adults, non-white (56% African-American), unemployed at the time of the injury, unmarried, history of illegal substance use, history of law enforcement encounters, poverty, and low educational level.
- Reducing the impact of TBI
- Strict limits in blood alcohol concentration
- The use of seatbelts
- Separate child restraint law
- Firmly enforced speed limits
- Compulsory helmets for motorcycle riders
- Clinical care improved with faster communication
- Better trauma systems
- Increased availability of CT scanning
- Improved intensive care unit (ICU) facilities and care
- Others
Pathology
- Brain injury from trauma results from two distinct processes:
- Primary brain injury:
- Occurs at time of trauma (cortical contusions, lacerations, bone fragmentation, diffuse axonal injury, and brainstem contusion)
- Secondary injury:
- Develops subsequent to the initial injury.
- Includes injuries from intracranial hematomas, edema, hypoxemia, ischemia (primarily due to elevated intracranial pressure (ICP) and/or shock), vasospasm
- Blast injury several mechanisms combine in damaging the brain
- Primary injury (due to pressure waves),
- Secondary injury (collision with debris and other objects),
- Tertiary (being thrown down by the blast and hitting the head against an object)
- Quaternary (heat and toxic injury).
Delayed deterioration
- ≈ 15% of patients who do not initially exhibit signs of significant brain injury may deteriorate in a delayed fashion
- Etiologies:
- ≈ 75% will exhibit an intracranial hematoma
- May be present on initial evaluation and can then worsen
- May develop in a delayed fashion
- Delayed epidural hematoma (EDH)
- Delayed subdural hematoma (SDH)
- Delayed traumatic contusions
- Posttraumatic diffuse cerebral edema
- Hydrocephalus
- Tension pneumocephalus
- Seizures
- Metabolic abnormalities, includes:
- Hyponatremia
- Hypoxia: etiologies include pneumothorax, MI, CHF…
- Hepatic encephalopathy
- Hypoglycemia: including insulin reaction
- Adrenal insufficiency
- Drug or alcohol withdrawal
- Vascular events
- Dural sinus thrombosis
- Carotid (or rarely, vertebral) artery dissection
- SAH: due to rupture of aneurysm (spontaneous or posttraumatic) or carotid-cavernous fistula (CCF)
- Cerebral embolism: including fat embolism syndrome
- Meningitis
- Hypotension (shock)
Assessment of outcome
Scale | GOS | Scale | GOSE |
1 | Dead | 1 | Dead |
2 | Vegetative | 2 | Vegetative |
3 | Severe disability | 3 | Lower severe disability |
ㅤ | (Conscious but dependent) | 4 | Upper severe disability |
4 | Moderate disability | 5 | Lower moderate disability |
ㅤ | (Independent but disabled) | 6 | Upper moderate disability |
5 | Good recovery | 7 | Lower good recovery |
ㅤ | (Can resume normal activities) | 8 | Upper good recovery |
- The Glasgow Outcome Scale (GOS) and beyond Accurate characterization of outcome after TBI is essential, both from a clinical and research perspective.
- Historically, most TBI studies have used the Glasgow Outcome Scale (GOS) or the extended version of the GOS (GOSE )to provide an overall global assessment of functional outcome after TBI
- GOS
- While appropriate for more severe TBI, it was recognized that the scale was relatively insensitive at the upper levels and for this reason the Glasgow Outcome Scale Extended (GOSE) was introduced.
- Alterations in major roles, independence in living and participation in social and leisure activities are assessed by the investigators and used to summarize the effects of diverse changes caused by injury.
- GOSE
- GOSE remains a global approach to classifying outcome
- Ceiling effects exist.
- TBI may cause problems in many domains:
- Neuropsychological sequelae include:
- Mood disturbances
- Cognitive impairment
- Personality changes
- Social and family effects.
- An overlap may exist between sequelae of mild TBI and symptoms consistent with PTSD. The overlap of cognitive disruption between mild TBI and PTSD reflect the complex interplay of neurological, psychological, and physical factors in veterans with mild TBI and/ or PTSD, and highlights the need for specialized evaluation and management
- Quality of life measures
- Generic measures
- Short- Form- 36 (SF36)
- Disease specific measure QOL
- Quality of Life after Brain Injury (QOLIBRI) scale.
- This scale provides a profile of health- related quality of life (HRQOL) in domains typically affected by brain injury.
- However, for more global assessments a summary measure may be preferable and as such the QOLIBRI- OS presenting a short six- item assessment was proposed.
- QOLIBRI was found to have moderate to strong relationships with
- QOLIBRI- OS,
- GOSE,
- Short- Form- 36,
- Hospital Anxiety and Depression scale
- An important aspect is to capture the patient’s own perspective on QOL
- To date, outcome assessments have tended to be unidimensional, focusing on single domains.
- An alternative approach might be to combine these in multidimensional assessment scores.
- Much further work will however be required to determine which instruments are best suited for specific situations and to determine the weighting of different factors.
- Historical data on outcome differentiated by severity of injury, show that patients with
- Severe TBI have a
- Mortality rate of 36%,
- 5% are classified as vegetative,
- 15% have severe disability,
- 15– 20% moderately disability, and
- 25% good recovery.
- Moderate injury
- Mortality of 7%,
- Vegetative classification of 1%,
- Severe disability rate of 7%,
- Moderate disability rate of 25%,
- Good recovery rate of 60%.
- Mild injury
- Very low mortality
- Substantial majority designated as good recovery
- Nevertheless a high frequency of ongoing symptoms including headache, visual disturbance, dizziness, fatigue, and memory, concentration, and higher executive function impacting on family and social life and employment.
- With advances in treatment there is evidence that six- month outcome has improved in moderate and severely injured patients treated in specialist intensive care (increased in moderate disability and good recovery from 40.4% to 59.9%) (Patel et al., 2002)
Health economic cost
- Economic cost of TBI management is tremendous
- Huge burden on society
- There are a paucity of studies that quantify this cost.
- Due to the long- term economic impact and burden of disability to family, work, and society, the average lifetime cost per person for TBI in the United States is estimated to be US$396 000.
- In the United States the Centre for Disease Control and Prevention estimates direct and indirect costs of TBI to be more than US$58 billion in total.
- In most studies, the costs of non- hospitalized TBI were not considered at all.
- Feigin et al. performed a population- based TBI study and found out that 30% of cases were from non- hospitalized patients
- Although the cost of TBI is known to increase by severity
- The unexpectedly large number of mild TBI in any population (95% of all TBI cases) means that the total cost of treating these cases is nearly three times that of moderate/ severe TBI.
- The economic burden and overall outcome can be reduced by targeting both high cost injuries and population- based programmes aimed at reducing the incidence of lower cost mild injuries.
Transfer of trauma patients
- Factors to assess in head injured patients
Neurosurgical exam in trauma
General physical condition
- Visual inspection of cranium:
- Evidence of basal skull fracture
- Raccoon’s eyes (AKA Panda bear sign): periorbital ecchymoses
- Battle’s sign: postauricular ecchymoses (around mastoid air sinuses)
- CSF rhinorrhea/otorrhea
- Hemotympanum or laceration of external auditory canal
- Check for facial fractures
- Le Fort fractures: palpate for instability of facial bones, including zygomatic arch
- Orbital rim fracture: palpable step-off
- Periorbital edema, proptosis
- Cranio-cervical auscultation
- Auscultate over carotid arteries:
- Bruit may be associated with indicated carotid dissection
- Auscultate over globe of eye:
- Bruit may indicate traumatic carotid-cavernous fistula (CCF)
- Physical signs of trauma to spine: bruising, deformity
- Evidence of seizure: single, multiple, or continuing (status epilepticus)
Neurologic exam
- Cranial nerve exam
- Optic nerve function (p.871)
- If conscious:
- Serial quantitation of vision in each eye is important.
- A Rosenbaum near vision card is ideal (see inside back cover), otherwise use any printed material. → Count fingers → hand motion vision → light perception.
- If unconscious:
- Check for afferent pupillary defect → Indicates possible optic nerve injury
- Children may develop transient cortical blindness lasting 1–2 days, usually after a blow to the back of the head
- Funduscopic exam:
- Quick assessment for
- Papilledema
- Pre-retinal haemorrhages
- Retinal detachment,
- Retinal abnormalities suggestive of anterior optic nerve injury.
- Detailed exam: pharmacologic dilatation with mydriatics
- This precludes pupillary exam for a variable period of time, and should be undertaken advisedly
- Pupil: size in ambient light; reaction to light (direct & consensual)
- CN VII: check for peripheral VII palsy (facial asymmetry of unilateral upper and lower facial muscles)
- VI: abducens palsy
- Following trauma may occur as a result of
- ⬆️ ICP
- Clival fractures
level of consciousness/mental status
- GCS
- Check orientation in patient able to communicate
Post traumatic amnesia
- Definition
- Length of time from injury until return of orientation and continuous memory for events
- Its duration has been associated with
- Presence or extent of skull fracture,
- Intracranial hemorrhage,
- Raised ICP
- Residual neurological deficits
- Extent of neuropathology,
- Longer-term functional outcomes
- Return to employment
- Post traumatic amnesia as a stronger predictor of (vs GCS/length of coma/socio-demographic factors)
- Longer-term functional outcome
- Return to employment
- Cognitive impairment
Motor exam
- Assesses motor tracts from motor cortex through spinal cord
- If patient is cooperative:
- Check motor strength in all 4 extremities
- If uncooperative:
- Check for appropriate movement of all 4 extremities to noxious stimulus (differentiate voluntary movement from posturing or stereotypical spinal cord reflex). This also assesses sensation in an unresponsive patient
- If any doubt about integrity of spinal cord:
- Check “resting” tone of anal sphincter on rectal exam,
- Evaluate voluntary sphincter contraction if patient can cooperate,
- Check anal wink with pinprick
- Assess bulbocavernosus reflex
Sensory exam
- Cooperative patient:
- Check pinprick on trunk and in all 4 extremities, touch on major dermatomes (C4, C6, C7, C8, T4, T6, T10, L2, L4, L5, S1, sacrococcygeal)
- Check posterior column function: joint position sense of LEs
- Uncooperative patient:
- Check for central response to noxious stimulus (e.g. grimace, vocalization…, as opposed to flexion-withdrawal, which could be a spinal cord mediated reflex)
Reflexes
- Muscle stretch (“deep tendon”) reflexes if patient is not thrashing:
- e.g. preserved reflex indicates that a flaccid limb is due to CNS injury and not nerve root injury (and vice versa)
- Check plantar reflex for upgoing toes (Babinski sign)
- In suspected spinal cord injury: the anal wink and bulbocavernosus reflex are checked on the rectal exam (see above
Indication for CT and admission criteria for TBI
Category 1. Low risk for intracranial injury
- Criteria Possible findings
- Asymptomatic
- H/A
- Dizziness
- Scalp hematoma
- Laceration
- Contusion or abrasion
- No moderate nor high risk criteria
- Extremely low likelihood of intracranial injury (ICI) of≤ 8.5 in 10,000 cases (with 95% confidence level)
- Management recommendations
- CT scan is not usually indicated.
- Plain SXRs are not recommended:
- 99.6% of SXRs in this group are normal.
- Linear non-displaced skull fractures in this group require no treatment, although in-hospital observation (at least overnight) may be considered.
- Criteria for observation at home
- Criteria for observation at home
- Head CT scan not indicated, or CT scan normal if indicated
- Initial GCS ≥ 14
- No high risk criteria
- No moderate risk criteria except loss of consciousness
- Patient is now neurologically intact (amnesia for the event is acceptable)
- There is a responsible, sober adult that can observe the patient
- Patient has reasonable access to return to the hospital E/R if needed
- No “complicating” circumstances (e.g. no suspicion of domestic violence, including child abuse)
- Sample discharge instructions for head injuries
- A change in level of consciousness (including difficulty in awakening)
- Abnormal behavior
- Increased headache
- Slurred speech
- Weakness or loss of feeling in an arm or leg
- Persistent vomiting
- Enlargement of one or both pupils (the black round part in the middle of the eye) that does not get smaller when a bright light is shined on it
- Seizures (convulsions or fits)
- Significant increase in swelling at injury site
Seek medical attention for any of the following:
Do not take sedatives or pain medication stronger than acetaminophen (paracetamol in some countries) for 48 hours. Do not take aspirin or other anti-inflammatory medications because of interference with platelet function and theoretical increased risk of bleeding.
Category 2. Moderate risk for intracranial injury
- Criteria
- History of change or loss of consciousness on or after injury
- Progressive H/A
- EtOH or drug intoxication
- Posttraumatic seizure
- Unreliable or inadequate history
- Age < 2 yr (unless trivial injury)
- Vomiting
- Posttraumatic amnesia
- Signs of basilar skull fracture
- Multiple trauma
- Serious facial injury
- Possible skull penetration or depressed fracture
- Suspected child abuse
- Management recommendations
- Head CT scan (unenhanced): clinical grounds alone may miss important lesions in this group.22 8–46% of patients with minor head injury (MHI) have an intracranial lesion (the most frequent finding was hemorrhagic contusion
- Observation
- At home, if the patient meets the criteria outlined above.
- In-hospital observation to rule out neurologic deterioration if patient does not meet criteria (including cases where CT scan is not done)
- Managing patients with in-hospital observation and only getting a CT scan in cases of deterioration (GCS score ≤ 13) is as sensitive as CT in detecting intracranial hematomas but is less cost effective than routinely performing an early CT scan and discharging patients who have a normal CT and no other indication for hospitalization
Category 3. High risk for intracranial injury
- Criteria Possible findings
- Depressed level of consciousness not clearly due to EtOH, drugs, metabolic abnormalities, postictal, etc.
- Focal neurological findings
- Decreasing level of consciousness
- Penetrating skull injury or depressed fracture
- Management recommendations
- Admit to hospital
- STAT unenhanced head CT scan
- If there are focal findings on neurologic examination
- Notify operating room to be on standby
- If CT scan or MRI is not available, consider emergency burr holes
- Determine if intracranial monitor (p.893) is indicated
- SXR usually not recommended:
- Useful for localizing a radio-opaque penetrating foreign body (knife blade, bullet…) for the O.R.
Other risk factors
- Occipital vs. frontal fractures
- Patients with occipital fractures may be at higher risk of significant intracranial injury (ICI)
- Frontal fractures
- Forward trauma: may protect oneself with the outstretched arms
- Facial bones and air sinuses exert an impact absorbing effect
- In 210 patients with facial fractures
- The highest incidence of ICI was seen in those with upper facial fractures
- Those with mandibular and midfacial region fractures (without upper facial involvement) had a lower likelihood of ICI
- Those with mandibular region trauma only were least likely to have ICI
Admitting orders for minor or moderate head injury
Admitting orders for minor head injury (GCS ≥ 14)
- Activity:
- Bed rest with HOB elevated 30–45°
- Neuro checks q 2 hrs
- q 1 hr if more concerned
- Consider ICU for these patients).
- Contact physician for neurologic deterioration
- NPO until alert;
- Then clear liquids, advance as tolerated
- Normal saline IVF:
- Note: the concept of “running the patient dry” is considered obsolete
- Mild analgesics:
- Paracetamol
- Codeine if necessary
- Anti-emetic:
- Give infrequently to avoid excessive sedation,
- Avoid phenothiazine anti-emetics (which lower the seizure threshold); e.g. use trimethobenzamide (Tigan®) 200mg IM q 8 hrs PRN for adults
Admitting orders for moderate head injury (GCS 9–13)
- Traditionally, mild head injury has been defined as GCS≥ 13. However, the increased frequency of both surgical lesions and CT scan abnormalities in patients with GCS= 13 suggests that they would be better classified with the moderate rather than mild head injuries.
- Orders as for minor head injury except patient is kept NPO in case surgical intervention is needed (including ICP monitor)
- For GCS= 9–12 admit to ICU.
- For GCS= 13, admit to ICU if CT shows any significant abnormality (hemorrhagic contusions unless very small, rim subdural…)
- Patients with normal or near-normal CTs should improve within hours.
- Any patient who fails to reach a GCS of 14–15 within 12 hrs should have a repeat CT at that time
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