Neuropathology of Injury protection expansion no lymphatics tight junctions tight junctions &...
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Transcript of Neuropathology of Injury protection expansion no lymphatics tight junctions tight junctions &...
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
Question: Which of the characteristics listed earlier would alter the production,
removal and consequences of cerebral oedema?
Oedema = escape of fluids, or failure to recirculate
CEREBRAL AND SPINAL CORD 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]
Oedema = escape of fluids, or failure to recirculate
CEREBRAL AND SPINAL CORD OEDEMA
Vasogenic oedema
• vessels
• protein rich
• astrocytes i/s space
• trauma, vascular, masses
Oedema = escape of fluids, or failure to recirculate
CEREBRAL AND SPINAL CORD OEDEMA
Cytotoxic oedema
• glial cell swelling
• protein free fluid
• BBB intact
• global
• hypoxic, ischaemic, T/N/M, genetic
BRAIN SWELLING
* 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
↑ tissue / fluid 2o fluid and pressure changes fatal:
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
further swelling cerebellum through foramen magnum
Herniation of brain tissue
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
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
blood supply
Vascular and circulatory lesions from:-
VASCULAR AND CIRCULATORY LESIONS
Vasculitis, eg EHV-1 arteritis in a horse
Vascular and circulatory lesions from:-
VASCULAR AND CIRCULATORY LESIONS
Thrombo-embolisim, eg Salmonella septicaemia in pigs
Vascular and circulatory lesions from:-
VASCULAR AND CIRCULATORY LESIONS
Hypoxia/ischaemia, eg neonatal seizures in a foal anaesthetic accident in a
dog
Vascular and circulatory lesions from:-
VASCULAR AND CIRCULATORY LESIONS
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