Download - Classification TBI
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