NP2B - Polio Flashcards
Which is both a specific name of a disease caused by thiamine deficiency and a morphologic diagnosis that can be attributed to a number of causes?
Polioencephalomalacia
Is a cofactor in oxidative energy pathways
Thiamine
What are the results of diminished thiamine for dependent areas of vasculature in the cerebrum?
Results in vasogenic edema that triggers the edema cycle
bumps ridges on the cerebral cortex
gyrus (plural: gyri)
a condition that occurs when there isn’t enough blood flow to the brain to meet metabolic demand
Cerebral ischemia
As you are closer to the meningeal surface, it will be ___________ necrosis
selective neuronal
(true/false) Polioencephalomalacia can be appreciated grossly by the naked eye
false
What species requires dietary thiamine, but usually get enough in the food?
Carnivores
So in pigs, the overgrowth is by Escherichia coli, and specifically E. coli that releases an enterotoxin that causes vascular leakage in multiple organ systems, and this is why we refer to this as _________
edema disease
In lambs, the offending agent is Clostridium perfringens, which released the epsilon toxin.
polioencephalomalacia
Epsilon toxin and Polioencephalomalacia in ruminants, goes by another name:
Focal Symmetrical Encephalomalacia
In what species is lead toxic to cerebral cortical neurons and the associated vasculature, just like thiamine deficiency, and the vascular component is prominent?
cattle
an enlarged phagocytic cell of microglial origin having the cytoplasm distended with lipid granules and being characteristic of some organic brain lesions
gitter cells
In what species does low-level chronic lead exposure doesn’t seem to affect the forebrain, but rather affects Schwann cells resulting in primary demyelination in the PNS?
horses
the major glial cell type in the peripheral nervous system
Schwann cells
_________________ will cause polioencephalomalacia regardless of species.
sudden reduction in Plasma Osmolality (salt toxicity)
What can cause Polioencephalomalacia in ruminants?
- thiamine deficiency
- bacterial exotoxins
- lead toxicity
______________ with thiamine deficiency have Polioencephalomalacia, but the distribution differs and we’re not reliant on the edema cycle to result in Pannecrosis.
Carnivores
_________ in carnivores has direct effects on GM necrosis, but it tends to be more of a selective neuronal necrosis and we’re not evoking the edema cycle
lead toxicity
Differentials for polioencephalomalacia are initiated by cytotoxic edema.
- rapid reduction of plasma osmolality
- hypoxemia or ischemia
Malacia with hemorrhage, bilateral symmetry in periventricular grey matter
Polioencephalomalacia in a cat due to Thiamine Deficiency
Thiamine deficiency, bacterial exotoxins and lead toxicity in ruminants can initiate:
vasogenic edema
Lead toxicity in _________- has direct effects on grey matter necrosis without the need for the edema cycle
carnivores
Polioencephalomalacia, bacterial exotoxins and vasogenic edema
Clostridium perfringens -> epsilon toxin
Escherichia coli -> edema disease principal
