NP1G Flashcards
What evaluation establishes the precise cause?
histological
the discoloration and cavitation is referred to as:
Malacia
Widespread necrosis, especially of neurons. (also supporting glial cells)
Pannecrosis
Polioencephalomalacia in a dog due to Necrotizing Meningoencephalitis: What do you look for if histology showed to be a very inflammatory lesion?
We look for an infectious agent, however, there was none
In the absence of any infectious ideology, we concluded that this must be an immune-mediated insult, one prime differential is necrotizing meningoencephalitis
Polioencephalomalacia in a dog due to Necrotizing Meningoencephalitis: What are some differentials?
loss of blood supply (infarction)
inflammation
exposure to a toxin
An idiopathic (unknown) inflammatory condition that affects pugs
Necrotizing Meningoencephalitis
Distribution is Key!: What happens if you see bilaterally symmetrical (in a brain stem of a cat) foci of hemorrhage and necrosis, affecting the caudal colliculi and medial vestibular nuclei?
Morphologic Diagnosis: Polioencephalomalacia with hemorrhage
Answer: bilaterally symmetrical suggests a toxic or metabolic disorder
A case of bilateral symmetry, and histology showed to be non-inflammatory. This concluded to be:
thiamine deficiency
Leukomalacia is caused by:
Demyelination and can be primary or secondary
You are seeing an extensive area of WM malacia, it was bilaterally symmetrical, and histologically you see vascular damage, much leakage, and associated secondary demyelination.
bilaterally symmetrical -> toxic or metabolic
demyelination -> both myelin and axons were lost
This is known as moldy corn toxicity in the horse
Looking at the spinal cord WM, goat: You note asymmetry and histologically it was very inflammatory
Since it is a Goat: Caprine Arthritis Encephalitis Virus (can infect microglia, cause them to become very activated, inappropriately present antigens associated myelin giving rise to an immune-mediated demyelination) For this we need molecular diagnostic testing
Is seen in the peripheral nervous system of a horse, seeing in the inner aspects some yellowish/brown discoloration caused by primary demyelination. It is thought to be an immune mediated process triggered by microbial infection earlier in life.
Equine Cauda Equina Neuritis
example: a macrophage-driven inflammatory response to a fungus in the brain stem of a dog
granuloma
brain stem and cerebellum of a goat: histologically you can see severe inflammation
bacterial infection caused by -> Listeria monocytogenes
brain stem and cerebellum of a goat: histologically you can see severe inflammation
bacterial infection caused by -> Listeria monocytogenes
When is the only time that you are seeing inflammatory changes grossly?
If it is causing Hemorrhage or Malacia
Ataxia in Horses differentials:
Spinal cord compression
Viral infection
Herpes Viral Myelitis
Protozoa myelitis
Defects in the ability of a neuron to sustain the axon because of defects in the axoplasmic transport mechanism
Neuraxonal Dystrophy
What can give rise to Leukoencephalomalacia?
Axon degeneration necrosis demyelination
Selective Necrosis (you don’t see anything grossly) and susceptibility to injury:
Neurons> Oligodendrocytes»_space; Astrocytes»_space; Microglia and Endothelial cells
Which group of cells tends to survive regardless of how severe the insult?
Microglia and Endothelial cells
(true/false) Selective neuronal necrosis can be seen immediately in a postmortem examination
false, it takes time. you will see nothing histologically
A dog had selective neuronal necrosis, the microglial cell phagocytizes a dead neuron and this is called:
Neuronophagia
Neuronal Storage Disorder: A cytologic change go back to this image:
We are in the cerebellum, the molecular cell layer to the left, and the internal granular cell layer to the right, the arrow is pointing to a Purkinje Cell full of clear vacuoles.
No inflammation is associated with this, the change is diffuse affecting all neuronal populations.
This is consistent with a Lysosomal Storage Disease or Neuronal Storage Disorder
What is most likely to give rise to polioencephalomalacia?
cerebrocortical pannecrosis
You observe bilateral symmetrical selective neuronal necrosis in the absence of inflammatory cell infiltrates. What would be included in your differential diagnoses?
toxin exposure or metabolic disorder
