CLASSIFICATIONOFTBI

Baroque NEUROTRAUMA REVIEW WORKSHOP30 May 2009

EPIDEMIOLOGY & STATISTICS

Major cause of unnatural death in SA 50% of all traumatic death result from TBI 75 – 80 % mild 10 % fatal (pre hospital) 300/100 000 TBI hospitalisation/year Male : Female 2 : 1 0 – 4 and 15 – 19 are the 2 age groups at

highest risk for a TBI >75 years highest rates of TBI related

hospitalisation and death

AETIOLOGY

Falls28%

MVA20%

Acciden-tal injury

19%

Assaults11%

Other10%

GSW12%

CLASSIFICATION

Mechanism – closed / penetrating Pathological - Primary / Secondary Severity - numerous Morphology – Focal / diffuse

MECHANISM

Closed / penetrating or open• Not a purely mechanistic division• Management implications

Closed: brain not in contact to the environment High \ low velocity

Penetrating/open: brain exposed – dural breached with or without FB High / low velocity

Severity: mild to fatal

PATHOLOGICAL

Primary / secondaryPrimary Injury Irreversible Induced by mechanical force Occurs at moment of injury

Secondary Injury• May be preventable or treatable Not mechanically induced Delayed from moment of injury; seconds to days May superimpose injury on primarily injured brain

PRIMARY INJURY

2 main mechanism Contact – impact / static

local & remote• Contusions • Fractures • Lacerations

Inertial • Angular• Rotational• Translational

Combination

PRIMARY INJURY

Subdivision Focal

• Contusion• Laceration• Fractures

Diffuse• Concussion• Diffuse axonal

injury

Open / closed

SECONDARY INJURY

FocalIntracranial haematoma

• Extradural • Subdural • Intracerebral

Herniation

Diffuse• Ischaemia – local / systemic (50 % of patients)• Cerebral swelling – local / systemic• Cytotoxicity(Na, Ca, aspartate, glutamate, ion pump failure, free

radicals, proteolysis, lipid peroxidation)

MORPHOLOGICAL

Focal / DiffuseFocal Fractures

Vault• Linear / stellate• Depressed / non-depressed

Basilar • With / without CSF leak• With / without nerve palsy

Lacerations (pia torn)

Contusions (pia intact)

• Fractures• Coup• Contra-coup• Intermediate coup(inferomedial temporal lobe, cingulate gyrus, corpus callosum, basal ganglia, brain

stem)

• Herniation• Gliding

MORPHOLOGICAL

Focal (cont.)

Haematomas • Extradural –

o Tearing of dural vessels o 85% arterial middle meningeal arteryo 15% venous

• Subdural• 2 types

• Burst lobe• Torn bridging vessels

• Intracerebral• Rupture of intrinsic cerebral vessels

• Subarachnoid Cranial nerve injuries - I,II, III, IV, V, VI,VII, VIII Pituitary & hypothalamic injury Arterial – CCF, aneurysm, dissection.

MORPHOLOGICAL

Diffuse Concussion

• Physiological Diffuse axonal injury

• Mild LOC 6 – 24 hours• Moderate LOC > 24 hours + decerebrate

posturing• Severe LOC > 24 hours + decorticate posturing

MORPHOLOGICAL

CT Classification ( Marshall)

Category Definition on CT Scan Mortality%

I Normal 10

II•0 – 5 mm midline shift•Basal cisterns patent•High or mixed density lesion <25 ml

14

III•0 – 5 mm midline shift•Effacement of basal cisterns •High or mixed density lesion <25 ml

34

IV

•Midline shift > 5mm•Effacement of basal cisterns•High or mixed density lesion lesion > 25 ml

56

SEVERITY

Head Injury Severity ScaleCategory GCS / LOC / Amnesia

Minimal15Or

No LOC or amnesia

Mild14 – 15

OrBrief LOC or amnesia

Moderate

9-13Or

LOC +/- 5minOr

Focal neurological deficit

Severe 5-8

Critical 3-4

SEVERITY

Head Injury or Traumatic Brain Injury Classification

Based on PTAPTA duration Severity

< 5 minutes Very mild

5 - 60 minutes Mild

1 – 24 hours Moderate

1 – 7 days Severe

1 – 4 weeks Very severe

> 4 weeks Extremely severe

SEVERITY

Arbitrary classification

Severity GCS Mortality

Mild 13 – 15 < 1 %

Moderate 9 – 12 2 – 5 %

Severe 3 - 8 40 – 50 %

SEVERITYMAYO TBI SEVERITY CLASSIFICATION SYSTEM A. Classify as Moderate-Severe (Definite) TBI if one or more of the

following criteria apply:1. Death due to this TBI2. Loss of consciousness of 30 minutes or more3. Post-traumatic anterograde amnesia of 24 hours ormore4. Worst Glasgow Coma Scale full score in first 24 hours13 (unless invalidated upon review, e.g., attributableto intoxication, sedation, systemic shock)5. One or more of the following present:• Intracerebral hematoma• Subdural hematoma• Epidural hematoma• Cerebral contusion• Hemorrhagic contusion• Penetrating TBI (dura penetrated)• Subarachnoid haemorrhage• Brain Stem Injury

SEVERITY

MAYO TBI SEVERITY CLASSIFICATION SYSTEM

B. If none of Criteria A apply, classify as Mild (Probable) TBI if one or more of the following criteria apply:1. Loss of consciousness of momentary to less than

30 minutes2. Post-traumatic anterograde amnesia of

momentary to less than 24 hours3. Depressed, basilar or linear skull fracture (dura

intact)

SEVERITY

MAYO TBI SEVERITY CLASSIFICATION SYSTEM C. If none of Criteria A or B apply, classify as

Symptomatic(Possible) TBI if one or more of the following symptoms are present:• Blurred vision• Confusion (mental state changes)• Dazed• Dizziness• Focal neurologic symptoms• Headache• Nausea

TBI