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