Head Injury (TBI)

M K Alam, MS; FRCSEd

Head Injury (TBI)• The most common cranial condition.

• Decline in mortality:

• 50% 1970s to 36% 1980s to 27% 1990s to 15% 2000s

• EMS, Critical Care, CTs

• USA: brain injury occurs every 7s, result in death every 5

min

• TBI: 1/3 of all trauma related deaths

• Motor vehicle accidents: 50%

• Incidence: M:F 2:1

2

Outcome of TBI

• Death : 30 -36%

• Severe Disability : 15%

• Moderate Disability : 14 – 20%

• Persistent vegetative state : < 5%

• Good Outcome : 25%

Causes of trauma

• RTA or MVA• Pedestrian trauma• Fall from height• Assault• Industrial accidents• Natural disasters• Explosions• Firearm injuries• Knife

Pre-hospital care• Delivery to the hospital for definitive care as rapidly

as possible- scoop and run

• Only critical interventions at the scene

• Airway established, hard collar, spine board, control any external hemorrhage

• Infusion on way to the hospital

Hospital care

• ATLS approach

• A well defined order

• Primary survey- initial assessment and management

• Treat the greatest threat to life

• Immediate intervention as the threat to life is identified

• Detailed history not essential

• Re-evaluation of initial management

• Secondary survey- a head to toe evaluation

Primary survey

• A B C D E• Airway & cervical spine protection

• Breathing

• Circulation

• Disability (neurologic assessment)

• Exposure and Environmental control

Disability Neurologic evaluation

• Level of consciousness measured by the Glasgow

Coma Scale (GCS)

• If the GCS is used in intubated and paralyzed

patients, record should be made

• Pupillary response can still be assessed in a

paralyzed patient

CLASSIFICATION OF TBI

Primary vs. SecondarySeverity - mild, moderate, severeMechanism

Closed (blunt) vs. PenetratingMorphology

Skull #sIntracranial lesion

Focal vs. Diffuse

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Glasgow Coma Scale (GCS), Total = 15 Eye response Vocal response Motor responseSpontaneous 4 Oriented 5 Obeys commands 6

To voice 3 Confused 4 Purposeful movement to pain 5

To pain 2 Inappropriate words 3

Withdraw from pain 4

None 1 Incomprehensible words 2

Flexion to pain 3

*** None 1 Extension to pain 2

*** *** None 1

PUPILSUnilateral Dilated:

CN III compression secondary to tentorial herniationTraumatic Mydriasis

Bilateral Dilated:Inadequate brain perfusion, bilateral CN III compression

Bilateral Miotic: Drugs, metabolic encephalopathy, Pontine lesion

Unilateral Miotic:Injured sympathetic pathway (e.g. carotid sheath injury)

Head injury severity

• Mild GCS ≥ 13

• Moderate GCS 9- ≤ 12

• Severe GCS ≤ 8

Secondary Survey

• Only after completion of primary survey

• All life threatening injuries dealt, normalization of vital signs

Secondary Survey:

• A head to toe evaluation

• Detailed history and examination

• Continuous reassessment of vital signs

• Additional laboratory/ radiological tests.

• Additional tubes, lines and monitoring devices

• Priorities and plan definitive management of all injuries

Head injury

• Traumatic brain injury (TBI)- the leading cause of death in trauma

patients. Upto 50% of all traumatic deaths.

• Primary injury- the anatomic and physiologic disruption that occurs

as a direct result of trauma

• Secondary injury- extension of the primary injury, result from local

swelling, increased ICP, hypoperfusion, hypoxemia, or other

factors.

• Aim- detection and treatment of primary injury and prevention of

secondary injury

MILD TBI

• 80% of all TBI (GCS ≥ 13)• 3% of pts with mild TBI deteriorate• How could I know if my patient is in the

3%?• Classification of mild TBI:– Admission GCS– Duration of LOC– Post traumatic amnesia– Focal neurological deficits

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MODERATE TBI

• 10% of all TBI pts seen in ER (GCS 9- ≤

12)

• 10% will deteriorate

• CT head in all

• Admission

• F/U CT16

SEVERE TBI

• GCS ≤ 8

• Will typically be evident by CT

• ICU required

• The worse the GCS the worse the

prognosis

• In this regard the motor component of

GCS is more important than the other 217

SKULL FRACTURES

• Fracture patterns depend on:– Thickness–Morphology– Composite nature of the bone

• Types– Linear– Depressed (open or closed)– Basilar or Basal

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LINEAR FRACTURES

• Most common

• Direct impact to the cranium

• From a broad surface

• Separation of the # edges (diastasis)

• Thinnest areas of the skull

• Squamous portion of temporal bone & damage

of middle meningeal artery - epidural

hematoma19

DEPRESSED FRACTURES

• Small surface area of the object

• Punched inwards• CSF leakage• Open (laceration of

scalp)• Infection• Seizures

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DEPRESSED FRACTURES

• Surgical intervention when:– > 8-10 mm depression (or > than the thickness of skull)– Deficit related to underlying brain– CSF leak– Compound fractures– Cosmetic region

BASAL FRACTURES Direct trauma to

Mastoid (Battle’s sign)OccipitalSupraorbital (Raccoon

eyes)

Indirectly to

Cribriform plate

CSF leak

RhinorrheaOtorrhea

Cranial nerves Carotid artery

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Subdural hematomaMore common than EDH

Acute form is associated with other significant brain injuriesCerebral contusion (67%)

Highest Mortality rate: 60-70%. (acute SDH)

Can be subdivided into Acute - less than 3 daysSubacute - 3 days to 3 weeksChronic - after 3 weeks 23

Subdural hematoma

• Surgical intervention when …– Symptomatic– SDH thickness > 1cm (5mm in Peds)– Midline shift > 5mm

• Positive Displacement Factor or shift out of proportion– Midline shift > SDH thickness

• Timing of Surgery:– Early : 0 – 4 Hrs from injury– Late : > 4 Hrs

Epidural hematoma

• An acute lesion• Commonly seen in frontal or

temporal region • 75-90% of patients with

epidural hematomas will have fractures.

• Middle meningeal artery (85%)

• “Lucid interval”• Surgery: > 5mm midline

shift, symptomatic, detoriation of GCS

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Epidural SubduralHematoma Hematoma

TRAUMATIC SAH• Most common lesion from

closed head injury.

• Significant SAH always associated with cortical contusions.

• Block arachnoid villus causing hydrocephalus.

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DAI (Diffuse axonal injury)

• Rotational injury forces (angular acceleration) can disrupt axons. DAI shows minimal gross alteration.

• SEVERITY: – Mild: coma 6 – 24 Hrs – Moderate: coma >24 Hrs without decerebrate posturing– Severe: coma > 24 Hrs + decerbrate posturing & flaccidity

– CLINICAL HALLMARK – prolonged loss of consciousness. – occurs immediately after the injury. – no correlation with external trauma or skull fractures.

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Intracranial hypertension

• Surgical intervention when:

– Progressive neurological deterioration

– Refractory high ICP

– GCS 6 – 8

– Frontal or temporal contusions >20 cm3

– Midline shift > 5mm

– Any lesion >50 cm3

Late complications of TBI

• Posttraumatic seizures

• Communicating Hydrocephalus

• Post-concussive syndrome

– Cluster of Symptoms (organic / psychological)

• Dizziness, visual disturbance, anosmia, hearing difficulty

• Difficulty concentrating

• Emotional difficulties, insomnia

Head injury- management summary

• Maintain BP >90 mmHg, PaO2 >60 mmHg

• Assess GCS and lateralizing signs- pupil and motor function

• Pupillary asymmetry >1 mm suggests intracranial injury

• Larger pupil is on the side of the mass lesion

• Extremity weakness- detected by testing motor power

• CT scan head- accurate localization of the lesion

• Epidural or subdural hematoma: evacuated• Intracerebral hematoma & contusion• Diffuse axonal injury: maintain brain perfusion & prevent rise in ICP.