NP1G

Question 1

What evaluation establishes the precise cause?

Answer 1

histological

Question 2

the discoloration and cavitation is referred to as:

Answer 2

Malacia

Question 3

Widespread necrosis, especially of neurons. (also supporting glial cells)

Answer 3

Pannecrosis

Question 4

Polioencephalomalacia in a dog due to Necrotizing Meningoencephalitis: What do you look for if histology showed to be a very inflammatory lesion?

Answer 4

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

Question 5

Polioencephalomalacia in a dog due to Necrotizing Meningoencephalitis: What are some differentials?

Answer 5

loss of blood supply (infarction)
inflammation
exposure to a toxin

Question 6

An idiopathic (unknown) inflammatory condition that affects pugs

Answer 6

Necrotizing Meningoencephalitis

Question 7

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?

Answer 7

Morphologic Diagnosis: Polioencephalomalacia with hemorrhage
Answer: bilaterally symmetrical suggests a toxic or metabolic disorder

Question 8

A case of bilateral symmetry, and histology showed to be non-inflammatory. This concluded to be:

Answer 8

thiamine deficiency

Question 9

Leukomalacia is caused by:

Answer 9

Demyelination and can be primary or secondary

Question 10

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.

Answer 10

bilaterally symmetrical -> toxic or metabolic
demyelination -> both myelin and axons were lost
This is known as moldy corn toxicity in the horse

Question 11

Looking at the spinal cord WM, goat: You note asymmetry and histologically it was very inflammatory

Answer 11

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

Question 12

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.

Answer 12

Equine Cauda Equina Neuritis

Question 13

example: a macrophage-driven inflammatory response to a fungus in the brain stem of a dog

Answer 13

granuloma

Question 14

brain stem and cerebellum of a goat: histologically you can see severe inflammation

Answer 14

bacterial infection caused by -> Listeria monocytogenes

Question 14

brain stem and cerebellum of a goat: histologically you can see severe inflammation

Answer 14

bacterial infection caused by -> Listeria monocytogenes

Question 15

When is the only time that you are seeing inflammatory changes grossly?

Answer 15

If it is causing Hemorrhage or Malacia

Question 16

Ataxia in Horses differentials:

Answer 16

Spinal cord compression
Viral infection
Herpes Viral Myelitis
Protozoa myelitis

Question 17

Defects in the ability of a neuron to sustain the axon because of defects in the axoplasmic transport mechanism

Answer 17

Neuraxonal Dystrophy

Question 18

What can give rise to Leukoencephalomalacia?

Answer 18

Axon degeneration necrosis demyelination

Question 19

Selective Necrosis (you don’t see anything grossly) and susceptibility to injury:

Answer 19

Neurons> Oligodendrocytes&raquo_space; Astrocytes&raquo_space; Microglia and Endothelial cells

Question 20

Which group of cells tends to survive regardless of how severe the insult?

Answer 20

Microglia and Endothelial cells

Question 21

(true/false) Selective neuronal necrosis can be seen immediately in a postmortem examination

Answer 21

false, it takes time. you will see nothing histologically

Question 22

A dog had selective neuronal necrosis, the microglial cell phagocytizes a dead neuron and this is called:

Answer 22

Neuronophagia

Question 23

Neuronal Storage Disorder: A cytologic change go back to this image:

Answer 23

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

Question 24

What is most likely to give rise to polioencephalomalacia?

Answer 24

cerebrocortical pannecrosis

Question 25

You observe bilateral symmetrical selective neuronal necrosis in the absence of inflammatory cell infiltrates. What would be included in your differential diagnoses?

Answer 25

toxin exposure or metabolic disorder