Nervous system pathology 3 Flashcards
Describe the pathology of FIP in the CNS
Antibody-antigen immunocomplexes deposit within the vessel wall
- > Immunemediate aggression
- > Diffuse pyogranulomatous meningo-chorio-subependimitis
Describe the dry form of FIP
- Dry form is dominated by granulomas – nodular lesions that aren’t rich in fluid
- First lesion can be seen in the eye which shows CNS involvement
Describe the wet form of FIP
- Wet form is characterised by the over-exudation of fluid
- Abdomen is distended by large volumes of fluid
What are the histological characteristics of FIP
- Prevalence of plasma cells and macrophages
- Vasculitis is the histological hallmark of the disease, with formation of microtrombi
Which other organ is infected by the dry form of FIP?
The kidney – white nodules on the surface are obliterating the profile of the vein – they are purposefully located over the vein
How would a slide of the cranial portion of brain appear for FIP?
- ‘Empty’ cavities represent the lateral ventricles. They are much wider and distended than normal
- The outlining silhouette is a blue line, this is abnormal as the CNS is normally completely pink staining, the blue represents a lot of nuclei (inflammatory cells) which are removing the coverage of the ventricular system
- Round aggregates are perivascular cuffs which show a paler area (vessel) surrounded by a ‘doughnut’ shape of dotted cells around it = hallmark of inflammation
- The ependyma is normally columnar epithelium with cilia has gone and is replaced with inflammatory cells
- The ventricle is filled with a protein rich fluid which is not normally present = outcome of vessel damage
Louping ill is seen in which 3 species?
Sheep
Horses
Pigs
How is Louping ill transmitted?
By ticks
What is the inflammatory pattern of Louping ill?
Non-suppurative polioencephalitis with neuronal necrosis, glial nodules and neuronophagia
For Louping ill, in which cells is the viral antigen seen?
Purkinje cells
Which part of the brain is affected by Louping ill?
Cerebellum
What are the signs shown by sheep with Louping ill, what is the cause of these signs?
Sheep ‘bounce’ because they have no coordination because the virus kills the purkinje cells in the cerebellum where perception is controlled
Which 4 diagnostic factors indicate Louping ill?
Sheep
Cerebellum
Lymphocytes
Plasma cells
What are 3 viral causes of viral vasculitis?
- Classical swine fever
- Hepatitis contagiosa canis (canine adenovirus type 1)
- Malignant catarrhal fever
Herpetic encephalomyelitis is caused by which virus?
Equine herpes virus 1
What is seen grossly in Herpetic encephalomyelitis?
Petechial or ecchymotic haemorrhages in white and grey matter of the spine
Describe the inflammatory pattern of herpetic encephalomyelitis
Vasculitis with thrombosis, suppurative myelitis and haemorrhages