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 protrusionHaemorrhagic 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  2 o 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