Neuropathology of Injury
Neuropathology of Injury

protection

expansion

no lymphatics

tight junctions

tight junctions & astrocyte processes
BBB
Neuropathology of Injury

capillaries not fenestrated
[except choroid plexus]

end arterioles

minimal interstitial space

minimal perivascular space

minimal connective tissue
[collagen and elastin]
CNS TRAUMA
Concussion: temporary loss of function unconsciousness for brain
paralysis for spinal cord
CNS TRAUMA
Contusion: disruption of architecture
with haemorrhage at impact
site or distant site
CNS TRAUMA
Laceration: severe and permanent
disruption of tissues with
haemorrhage and necrosis
Haemorrhage
Acute brain
swelling and
unregulated
vasodilation
Myelomalacia - necrosis or
softening of spinal cord
Type-1 disk protrusion
Haemorrhagic myelomalacia
RAISED INTRACRANIAL PRESSURE
oedema
haemorrhage
abscess
tumour
generalised inflammation
increased CSF production
decreased CSF drainage
generalised signs
CEREBRAL AND
SPINAL CORD
OEDEMA
Oedema = escape of fluids, or failure to recirculate
Question: Which of the characteristics
listed earlier would alter the production,
removal and consequences of cerebral
oedema?

protection

expansion

no lymphatics

tight junctions

tight junctions & astrocyte processes
BBB

protection - p

expansion

no lymphatics

tight junctions

tight junctions & astrocyte processes
BBB

protection - p

expansion - c

no lymphatics

tight junctions

tight junctions & astrocyte processes
BBB

protection - p

expansion - c

no lymphatics - r

tight junctions

tight junctions & astrocyte processes
BBB

protection - p

expansion - c

no lymphatics - r

tight junctions – p & r

tight junctions & astrocyte processes
BBB

protection - p

expansion - c

no lymphatics - r

tight junctions – p & r

tight junctions & astrocyte processes
BBB – p & r

capillaries not fenestrated
[except choroid plexus]

end arterioles

minimal interstitial space

minimal perivascular space

minimal connective tissue
[collagen and elastin]

capillaries not fenestrated – p & r
[except choroid plexus]

end arterioles

minimal interstitial space

minimal perivascular space

minimal connective tissue
[collagen and elastin]

capillaries not fenestrated – p & r
[except choroid plexus]

end arterioles - p

minimal interstitial space

minimal perivascular space

minimal connective tissue
[collagen and elastin]

capillaries not fenestrated – p & r
[except choroid plexus]

end arterioles - p

minimal interstitial space - c

minimal perivascular space

minimal connective tissue
[collagen and elastin]

capillaries not fenestrated – p & r
[except choroid plexus]

end arterioles - p

minimal interstitial space - c

minimal perivascular space - c

minimal connective tissue
[collagen and elastin]

capillaries not fenestrated – p & r
[except choroid plexus]

end arterioles - p

minimal interstitial space - c

minimal perivascular space - c

minimal connective tissue - ?
[collagen and elastin]
CEREBRAL AND SPINAL CORD OEDEMA
Oedema = escape of fluids, or failure to recirculate
Vasogenic oedema
• vessels
• protein rich
• astrocytes  i/s space
• trauma, vascular, masses
CEREBRAL AND SPINAL CORD OEDEMA
Oedema = escape of fluids, or failure to recirculate
Cytotoxic oedema
• glial cell swelling
• protein free fluid
• BBB intact
• global
• hypoxic, ischaemic, T/N/M, genetic
BRAIN SWELLING
↑ tissue / fluid  2o fluid and pressure changes  fatal:
* brain abscess in a calf
* Coenurus cerebralis cyst forebrain of sheep
* astrocytoma, Boxer dog
* feline infectious peritonitis panencephalitis in a cat
* head trauma + cerebral oedema in a goat kid
* thiamin-responsive, cerebral cortical necrosis in a lamb
Herniation of brain tissue
right cerebral swelling  to left under falx cerebri
pressure on thalamus
Herniation of brain tissue
right cerebral swelling  caudally under tentorium
cerebelli
pressure on midbrain
Herniation of brain tissue
further swelling  cerebellum through foramen magnum
pressure on medulla oblongata
VASCULAR AND CIRCULATORY LESIONS
blood supply
Brain - carotid and vertebral arteries, circle of Willis
anastomoses pia-arachoid, then end arteries
collateral supply poor
VASCULAR AND CIRCULATORY LESIONS
blood supply
Spinal cord - vertebral aa. (C), radicular aa. (T-L)  ventral spinal a.
central grey matter-branches of ventral spinal a.
white matter - meningeal vs. via end arteries
VASCULAR AND CIRCULATORY LESIONS
Vascular and circulatory lesions from:-
Vasculitis, eg EHV-1 arteritis in a horse
VASCULAR AND CIRCULATORY LESIONS
Vascular and circulatory lesions from:Thrombo-embolisim, eg Salmonella septicaemia in pigs
VASCULAR AND CIRCULATORY LESIONS
Vascular and circulatory lesions from:-
Hypoxia/ischaemia, eg neonatal seizures in a foal
anaesthetic accident in a dog
VASCULAR AND CIRCULATORY LESIONS
Vascular and circulatory lesions from:-
Coagulopathies, eg DIC in septic mastitis
VASCULAR AND CIRCULATORY LESIONS
Question: Why should grey matter be
more susceptible than white
mater to many vascular and
circulatory insults?
VASCULAR AND CIRCULATORY LESIONS
Infarction