Nervous system pathology 2 Flashcards
Name some examples of CNS vascular lesions
- Ischaemic brain infarct
- Ischaemic encephalopathy
- Haemorrhagic brain infarct
- Haematoma
- Feline hypertensive encephalopathy
Define Atherosclerosis
Thickening or hardening of arteries
Which vascular condition affects the spinal cord?
Embolic encephalomyelitis
What are the clinical and diagnostic hallmarks of CNS vascular lesions?
Diagnostic hallmark: Focal or non-symmetrical multifocal haemorrhagic or malacic lesions
Clinical Hallmark: Acutely developing neurological symptoms without appreciable progression
Which features of the CNS make it susceptible to ischaemia?
- High metabolic request (one third of total glucose)
- Impossibility for local storage (e.g. glycogen)
- Ischemia starts after 60% decrease of blood flow
What is the order in which the cells of the CNS are most susceptible to ischaemia?
Neurons > oligodendrocytes > astrocytes > microglia and endothelial cells
A few minutes of hypoxia leads to?
Neuronal cell death
What are the two ways that reduced oxygen levels reach the brain?
- Ischaemia: reduced flow of normally oxygenated blood
- Hypoxia: normal flow of poorly oxygenated blood
What are 3 causes of an ischaemic brain infarct?
- Vascular thrombosis
- Emboli (e.g. mitral valve endocarditis, tumour emboli)
- Intracarotid injection (horses)
How will the grey and white matter appear in an acute infarct infection?
Grey: hyperaemia and astrocytosis
White: rale area with ‘red neurones’ and spheroids
What is astrocytosis?
An abnormal increase in the number of astrocytes due to the destruction of nearby neurons from central nervous system (CNS) trauma, infection, ischemia, stroke, autoimmune responses or neurodegenerative disease.
How will the grey and white matter appear in a chronic infarct infection?
Grey: glial scar formation
White: liquefactive necrosis and astrogliosis
Under histology what does a ‘rusty’ colour represent?
Haemosiderin
What is the cause of hemosiderin being found in the CNS?
Accidental injection into arteries e.g. carotid, causing inflammation of vessels (phlebitis)
How will infarction in the spinal cord appear grossly?
Bruise like appearance – haemorrhage and necrosis of consecutive sections
If fibrocartilaginous material is seen within the lumen of small arteries what lesion will occur?
Fibrocartilaginous embolism
Which vascular condition is extremely common in horses?
Siderocalcinosis of vessels