2. Brain protection
• Bony skull
• Falx cerebri
• Tentorium cerebelli
• Cerebrospinal fluid
Injuries to brain arise due to differences in
motion of the skull and brain
4. Scalp injuries
• Injuries bleed profusely
• Blunt trauma may result in apparently “clean
cut” laceration, but bruising at edges and hair
driven into wound.
• Bruises easily palpable, shave hair to visualise
fully. “Hair hides”
5. “Black eye”
May be due to:
• Direct blow into the orbit
• An injury to the front of the scalp, draining
down over the supraorbital ridge
• A fracture of the base of the skull (direct or
contrecoup) allowing meningeal hemorrhage
to escape through the orbital roof
6.
7.
8.
9. Skull Fracture
Skeleton of the head consists of three main
components:
• Mandible
• Facial skeleton
• Calvarium
Skull distorts when force is applied to it. Fracture
represents site of maximum stress on skull and
may not be at site of impact
10. Brain injury
• Skull fracture is a marker for the severity of force
applied to head.
• In general there is a correlation between them
• In the absence of fracture, rotary movements of
head cause shear strains within brain resulting in
diffuse axonal injury, contusion and laceration
• Cerebral oedema and haemorrhage are secondary
effects
11. • By direct intrusion, either by a foreign object
such as a penetrating weapon, bullet or other
missile – or fragments of skull in a compound
fracture where the skull is disrupted
• By deformation of the brain in closed head
injuries
12.
13. Cerebral injuries (types)
• Cerebral contusion-When either linear or, more
often, laminar stresses are applied to the cortex,
this soft tissue may disrupt
• Cerebral laceration-Laceration of the cortex is an
extension in severity of contusion in which
mechanical separation of the tissue can be seen.
• Traumatic intracerebral hemorrhage-Substantial
areas of hemorrhage, either infiltrating the brain
tissue or forming actual hematomas
14. • Primary brainstem hemorrhage-Secondary
brainstem bleeding is dealt with under ‘cerebral
oedema’ so here we are concerned with
hemorrhage that occurs at the time of injury
• Coup and contrecoup damage
• Concussion-is a clinical, not a pathological entity,
but the pathologist must consider it, as it is
related to intracranial lesions and he is often
questioned about it in court proceeding
15. • Diffuse neuronal and axonal injury-diffuse
brain damage exists in four principal forms:
diffuse vascular injury, diffuse axonal injury,
hypoxic brain damage and diffuse brain
swelling
• Cerebral oedema-Swelling of the brain tissue
may be a local phenomenon around almost
any lesion, be it contusion, laceration, tumor
or infarct
16. Signs of diffuse axonal injury
• Diffuse petechial
• haemorrhages in corpus callosum
• Typically traumatic but may also occur in:
– Fat embolism
– Hypertensive encephalopathy
– Malaria
17. Signs of cerebral oedema
• Increased brain weight
• Flattening of gyri and obliteration of sulci
• Hippocampal herniation (unilateral)
• Cerebellar tonsillar herniation
• Mid brain haemorrhage as a consequence of
vascular occlusion and haemorrhagic infarction
20. Linear fracture
• These are straight or curved fracture lines,
often of considerable length
• They either radiate out from a depressed zone,
or arise under or at a distance from the impact
area, from bulging deformation
• They may involve the inner or outer table, but
commonly traverse both
21.
22. Hinge fracture
• Blow to the top of the head commonly results
in linear fractures that pass down the parietal
plates.
• May extend across base of skull in middle
fossa passing through pituitary fossa
• Indicates severe force as seen in road traffic
accidents (motor cyclist’s fracture) or fall from
a high building
23.
24. Ring fracture
• These occur in the posterior fossa around the
foramen magnum and are most often caused
by a fall from a height onto the feet
• If the kinetic energy of the fall is not absorbed
by fractures of the legs, pelvis or spine, the
impact is transmitted up the cervical spine
• This may be rammed into the skull, carrying a
circle of occipital bone with it
25.
26. Pond fracture
• This is merely a descriptive term for a shallow
depressed fracture forming a concave ‘pond’
• It is more common in the more pliable bones
of infants and, indeed, a depression can occur
in the absence of a fracture
27.
28. Base of skull fracture
• Falls from a height on to the feet transmit
force through the legs and spine to the base of
skull forming a ring fracture around the
foramen magnum
• Similar fracture seen when the force from a
blow to the top of head is transmitted to base
of skull
29.
30. Spider’s web fracture
• Localised blow to skull will cause “spider’s
web” fracture with radiating lines and
concentric circles
35. “Blow-out” fracture
• Very thin orbital plates fracture easily and
may be only sign of trauma
• Direct injury to orbit
• Impact on occiput may cause contre coup
fracture of roof of orbit
39. Pathological consequences of intra-cranial
haemorrhage
• Space occupying mass
• Displaces brain laterally and downward
• Raised intra-cranial pressure
• Decreased blood flow to brain
• Herniation of hippocampus below tentorium
• Coning of brain stem
40.
41. Extra-dural haemorrhage
• Traumatic in origin, occurs in 2% of head injuries
• Fracture of temporal bone crossing branch of
middle meningeal artery
• Classical “lucid interval”
• Relatively rapid onset (arterial bleeding)
• Symptoms may be confused with alcohol
intoxication
• Drunk with head injury in police custody
45. Sub-dural haemorrhage
• Traumatic in origin but degree of trauma may
be relatively trivial
• Rupture of cortical veins, relatively slow onset
(venous bleeding)
• Particularly seen in children (shaking) and in the
elderly (cerebral atrophy)
• May be chronic and histology can assist in
estimating age in relation to previous trauma
49. Dating a Subdural hemorrhage
• 5 days-hematoma gradually changes from dark
red to a brownish color (obvious at 10-12/7)
• 12 days-presence of a membrane firm enough
to be picked off with forceps
50. Sub-arachnoid haemorrhage
• Spontaneous rupture of aneurysm on Circle of
Willis
• May occur as a complication of cerebral
contusion or as an extension of an intra-
cerebral haemorrhage
51.
52. Traumatic Sub-arachnoid haemorrhage
• Kick or blow to the side of the neck
• Traumatic dissection of vertebral artery
within the cervical spine
• Most vulnerable at level of first cervical
vertebra
• Posterior fossa sub-arachnoid haemorrhage
58. Spinal Injuries
• The spine and head should be thought of as
part of the same system in relation to trauma
• Compression damage-occurs when the victim
falls from a height either onto his feet or his
head, though in the latter case, head injuries
may overshadow damage to the spine, as well
as absorbing most of the impact
59. • Hyperflexion and hyperextension injury-
hyperextension is much more dangerous in
causing spinal damage, possibly because
flexion is protected by contraction of the
strong posterior neck muscles, whereas the
weak anterior longitudinal ligament is
incapable of preserving the integrity of the
cervical spine during hyperextension
60. • Spinal cord injury-Most damage to the spinal
cord arises from intrusion of some part of the
spinal column into the canal, be it bony
fragments or displacement, ligamentum
flavum, disc annulus or extruded nucleus
pulposus
