Head injuries from physical trauma can result in skull fractures, brain parenchymal injuries, and vascular injuries, which can all occur simultaneously. Trauma can cause closed or open head injuries that are either penetrating or blunt. The consequences of central nervous system trauma depend on the location of the lesion and the brain's limited ability to repair itself. Even injuries affecting just a few cubic centimeters of brain tissue can result in outcomes ranging from no symptoms to severe disability or death depending on the specific location.

1. Trauma Brain Injury
Head injuries by physical forces may result
in:
Skull fractures
Parenchymal injuries
Vascular injuries
All three can coexist
Trauma may produce closed or open head
injuries
Injuries may be penetrating or blunt
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2. Trauma
The consequences of CNS trauma depend
on
Anatomic location of the lesion
Limited capacity of the brain for functional
repair
Injury of several cubic cm of brain
parenchyma may be:
Clinically silent: e.g. in the frontal lobe
Severely disabling: in the spinal cord
Fatal: in the brainstem
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3. Trauma
 Skull fractures
 The incidence of fractures is related to the pattern of falls
 Falling while awake: the site of impact is often in the
occipital portion
 Following loss of consciousness: results in a frontal impact
 Four types of fractures:
 Linear: the most common
 Depressed: (displaced)
 Diastatic: crosses the sutures
 Basilar:
 Typically follows impact to occiput or sides of the head
 Lower cranial nerves or cervicomedullary region
symptoms: orbital or mastoid hematomas, CSF discharge
(rhinorrhea & otorrhea), and meningitis
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4. “LINEAR” “DEPRESSED
”, aka
“DISPLACED”
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5. Trauma
Parenchymal injuries
 Concussion
 Mild traumatic brain injury commonly due to
change in the momentum of the head
 Characterized by a transient neurologic
dysfunction that includes: loss of
consciousness, temporary respiratory arrest and
loss of reflexes
 The neurologic recovery is complete, but
amnesia for the event persists
 Concussion usually does not produce
parenchymal damage
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6. Trauma
Parenchymal injuries
 Contusion
 Bruise in the brain caused by blunt trauma
 Occurs when brain contacts rough skull surfaces
 Frontal and temporal lobes are the most
common locations
 Coup and contrecoup contusions
 Symptoms include: drowsiness, confusion,
agitation, hemiparesis, unequal pupil size
Laceration
 Caused by penetration of an object and tearing
of tissue
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7. Trauma
Parenchymal injuries
Diffuse axonal injury
Injury to axons at nodes of Ranvier with
impairment of axoplasmic flow
Is due to acceleration /deceleration even
in absence of impact
Results in coma after trauma without
evidence of direct parenchymal injuries
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8. Contusion
Morphologic changes
Acute: wedge-shaped hemorrhage
Subacute: necrosis / liquefaction
Chronic: plaque jaune lesions; depressed,
retracted, yellowish brown patches
Stages of changes:
Early: edema and hemorrhage
Next few hours: blood extravasation into
the white matter and subarachnoid space
By 24 hours: neuronal reaction to damage
Old contusions: gliosis and hemosiderin
laden macrophages 8

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10. Trauma
Traumatic vascular injury
Results from direct trauma and disruption of
the vessel wall and leads to hemorrhage
Hemorrhage may occur in
Epidural
Subdural
Subarachnoid
Intraparenchymal compartments
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12. Epidural hematoma
Associated with skull fractures
Does not cross suture lines
Due to tearing of dural arteries, mostly the
middle meningeal artery
Extravasation of blood separates the dura
from the inner surface of the skull
Blood accumulates slowly (“lucid interval” -
talk and die syndrome)
may expand rapidly and becomes a
neurosurgical emergency requiring prompt
drainage
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14. EPIDURAL
HEMATOMA
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15. Subdural hematoma
Due to rupture of bridging veins
May cross suture lines
Predisposing conditions:
Abnormal hemostasis
Elderly: with brain atrophy due to
stretching of veins
Infants: because of their thin-walled veins
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17. Subdural hematoma
Clinical features:
Hematomas manifest within 48 hours of injury
Most commonly over the lateral aspects of
cerebral hemispheres
Slowly progressive neurological deterioration
headache, and confusion are the most
common features, but drowsiness, focal
neurological deficits, and sometimes
dementia may also occur
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18. Subdural hematoma
 Morphology – Acute
 Freshly clotted blood along the brain surface
 The underlying brain is flattened
 Venous bleeding is self-limited → breakdown and
organization:
 Lysis of the clot (about 1 week)
 Growth of fibroblasts from the dural surface (2
weeks)
 Early development of hyalinized connective tissue
(1 to 3 months)
 Retraction of the lesion as granulation tissue
matures until there is only a thin layer of
connective tissue (subdural membranes)
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19. SUBDURAL
HEMATOMA
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21. Subarachnoid hemorrhage
 Is often a manifestation of cerebrovascular
disease
 Most common cause is rupture of saccular
(berry) aneurysm
 May also result from extension of a traumatic
hematoma, vascular malformation, hematologic
disturbances, and tumors
 Blood accumulates in ventricles, sulci, and
cisterns- chiasmatic cistern via A.Cerebral
artery.
 Clinical features include: sudden headache,
nuchal rigidity, neurological dificits on one side,
and stupor
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23. SUBARACHNOID 23

24. Intracerebral hemorrhage
Is often a manifestation of cerebrovascular
disease
Occurs most commonly in middle to late
adult life (peak at 60 years)
Hypertension is the most common cause
Other causes include: cerebral amyloid
angiopathy, coagulation disorders,
neoplasms, vasculitis, aneurysms, and
vascular malformations
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26. INTRAPARENCHYMAL
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29. Sequelae of brain trauma
Broad neurologic syndromes may manifest
months or years after trauma:
Post-traumatic hydrocephalus
Post-traumatic dementia
Punch-drunk syndrome
Post-traumatic epilepsy
Risk of infections
Psychiatric disorders
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31. Spinal cord trauma
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Associated with transient or
permanent displacement of
vertebral column
The level of injury determines
the extent of manifestation:
Thoracic segments or below –
paraplegia
Cervical segments –
tetraplegia
Above C4 – respiratory arrest