Neuropathology- Recognising the abnormal Flashcards
What is the prevalence of neurological disease in dogs?
- Brain = 2.5%
- Spinal Cord = 2%
What animal species has a 25% prevalence of pituitary tumours?
Rats
Where do sensory nerves enter the spinal cord?
Via the dorsal root
What is malacia?
softening and necrosis of nervous tissue, complete loss of architecture and cells
What does malacia look like grossly?
cavitation and haemorrhage (e.g an abscess)
Where does fibrosis occur?
Only in the meninges
Why does fibrosis only occur in meninges?
Fibrogenic cells are restricted to meninges and perivascular
Name 5 potential causes of traumatic brain injury
- Road traffic collisions
- Falls
- Deliberate blunt force trauma
- Penetrating wounds
- Iatrogenic wounds
What is the name of a lesion immediately below the site of an impact
Coup
* More severe if the head is stationary. but mobile, at impact
What is a contre-coup?
Lesions away from the site of impact
* More severe if impact is with a stationary object
What is contusion?
Injury to tissue without laceration
What is contusion subdivided into?
- Contusion haemorrhages- vascular injury predominates
- Contusion necrosis- parenchymal injury is the principal feature
What does spinal cord contusion look like?
- Damage to the microvasculature following impact
- More severe in grey matter
- haemorrhagic myelomalacia
- ascending and descending haemorrhagic myelomalacia
What does spinal cord compression look like?
- When the spinal cord is narrowed
- resulting pathology- depends on the speed in which the compression develops
What causes intervertebral disc disease in dogs?
herniated disc material normally moves dorsally
leads to compression of overlying spinal cord
What does wobbler syndrome lead to?
leads to cord compression
occurs in large breed horses and dogs
What does wobbler syndrome look like microscopically?
Axonal swelling follwed by necrosis
What is an oligodendroglioma?
Growth of cells that starts in the brain
What is a primary injury?
- Mechanical disruption of tissue
- Microvascular lesions (haemorrhage and oedema)
What is a secondary/ delayed injury?
Occurs within hours -> days after injury
* cascade of changes leading to ischaemia and oedema
* frequently fatal
What are the two main microvasculature damages?
- Haemorrhage
- Oedema
What are the 4 places a haemorrhage can appear?
haematoma- focal accumulation of blood
- Epidural
- Subdural
- Subarachnoid
- Intracerebral
What does oedema cause?
Compression of the CNS within the bony vault of the skull or vertebrae
can cause both primary and secondary injury
What is myelomalacia?
Softening of the spinal cord
What are the two types of contusion?
- Haemorrhagic myelomalacia
- Ascending and Descending Haemorrhagic myelomalacia
What is the pathogenesis of intervertebral disc disease?
- Herniated disc material moves dorsally
- leads to compression of the overlying spinal cord
