Brain Trauma Majda M Thurnher • The skull provides the brain with a protective thick, bony encasement • yet its irregular interior presents opportunities for damage to the fragile tissues it has evolved to protect Traumatic Brain Injury (TBI) Glasgow Coma Scale The Glasgow Coma Scale is based on a 15 point scale for estimating and categorizing the outcomes of brain injury on the basis of overall social capability or dependence on others. Mild (13-15): Moderate Disability (9-12): Loss of consciousness greater than 30 minutes Physical or cognitive impairments which may resolve Severe Disability (3-8): Coma: unconscious state. No meaningful response, no voluntary activities Vegetative State (Less Than 3): Sleep wake cycles Arousal, but no interaction with environment No localized response to pain Classification of TBI • Mechanism: closed or penetrating • Severity: mild, moderate, severe • Pathology: primary or secondary • Morphology: focal or diffuse 1. PRIMARY HEAD INJURY Scalp injuries Skull fractures Extra-axial hemorrhages Intra-axial injuries 2. SECONDARY HEAD INJURY Ischemia Hypoxia Hypotension Cerebral edema Meningitis / Abscess Increased intracranial pressure Classification of TBI Primary brain injury refers to the sudden and profound injury to the brain that is considered to be more or less complete at the time of impact. Secondary brain injury refers to the changes that evolve over a period of time (from hours to days) after the primary brain injury. It includes an entire cascade of cellular, chemical, tissue, or blood vessel changes in the brain that contribute to further destruction of brain tissue.
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Brain Trauma
Majda M Thurnher
• The skull provides the brain with a protective thick, bony encasement
• yet its irregular interior presents opportunities for damage to the fragile tissues it has evolved to protect
Traumatic Brain Injury (TBI)
Glasgow Coma Scale
The Glasgow Coma Scale is based on a 15 point scale for estimating and categorizing the outcomes of brain injury on the basis of overall social capability or dependence on others.
Mild (13-15):
Moderate Disability (9-12):Loss of consciousness greater than 30 minutesPhysical or cognitive impairments which may resolve
Severe Disability (3-8):Coma: unconscious state.No meaningful response, no voluntary activities
Vegetative State (Less Than 3):Sleep wake cyclesArousal, but no interaction with environmentNo localized response to pain
Classification of TBI
• Mechanism: closed or penetrating
• Severity: mild, moderate, severe
• Pathology: primary or secondary
• Morphology: focal or diffuse
1. PRIMARY HEAD INJURYScalp injuriesSkull fracturesExtra-axial hemorrhagesIntra-axial injuries
2. SECONDARY HEAD INJURYIschemiaHypoxiaHypotensionCerebral edemaMeningitis / AbscessIncreased intracranial pressure
Classification of TBI Primary brain injury refers to the sudden and profound injury to the brain that is considered to be more or less complete at the time of impact.
Secondary brain injury refers to the changes that evolve over a period of time (from hours to days) after the primary brain injury.
It includes an entire cascade of cellular, chemical, tissue, or blood vessel changes in the brain that contribute to further destruction of brain tissue.
1. PRIMARY HEAD INJURY
Scalp injuries
Skull fractures
Extra-axial hemorrhages
Intra-axial injuries
Epidural hematoma Subdural hematoma
Extra-axial hemorrhages
Subarachnoid &intraventricular hemorrhage
Epidural Hematoma (EDH)
Blood collection in space between inner table of skull and outer layer of dura
• Laceration or tearing of meningeal arteries• 90% arterial • 10% venous
• YOUNG ADULTS, rare in elderly• M:F 4:1
Epidural Hematoma (EDH)
NECT• hyperdense• biconvex or lenticular-shaped• smooth• compresses underlying brain• midline shift• does not cross sutures
(dura is attached to the calvarium tightly along the sutures)
Epidural Hematoma (EDH)
• Internal hypodense component
• Active bleeding with unretractedcloth
SWIRL SIGN
• Adjacent to venous sinus• Fracture through sinus• Slow accumulation of blood • Can cross falx and tentorium
• overall mortality 5%, bilateral EDH 15-20%• 10-25% will show enlargement within 1-36 h(“lucid interval” before it becomes large enough to cause unconsciousness)
• majority require surgical evacuation
• the bleeding stops when intracranial pressure exceeds arterial pressure
Therapy and prognosis of EDH
Blood collection in subdural space
Subdural Hematoma (SDH) • Tearing of bridging cortical veins• most common in ELDERLY
• no gender predilection
ng of bridging cortical veinsSubdural Hematoma (SDH)
• Supratentorial convexity• Posterior fossa, along the falx • Adjacent to the tentorium
Subdural Hematoma (SDH)
Acute SDH > 1 week
Subacute SDH 1-3 weeks
Chronic SDH > 3 weeks
Subdural Hematoma (SDH)
• sickle-shaped, crescentic • 60% hyperdense• 40% mixed • smooth defined borders• may cross sutures• compression of the ventricle• midline shift• may have SWIRL SIGN
Acute Subdural Hematoma (a (aSDHH)
“Subdural window setting”
Window 150-300 HU
Center/level 50-100 HU
Isodense or hypodense aSDH
• Anemia (low Hemoglobin)• Hematoma without clot• Tears in pia/arachnoid membrane result in CSF
leakage into SDH = dilution • Coagulopathy
Subdural Hematoma (SDH)
CAVEAT!
NECT• mixed density (recurrent hemorrhage) • gray-white junction displaced medially (“thick cortex”)• „dots“ of CSF = displaced cortical vessels