NP2A - Edema Flashcards
What can result from swelling of tissue in the CNS, when sitting in the cranial vault?
It results in increased intracranial pressure, which turn can reduce blood flow to the brain.
Leaky blood vessels
Vasogenic
Is fluid accumulation within astrocytes
Cytotoxic
Is caused by fluid accumulation that slits myelin lamella and transependymal, which is a push of CSF across the pendulum into periventricular WM
Intramyolynic
Where is it easier to spread fluid?
fluid will tend to spread in WM tracks because it is easier to create extracellular space than in the neuropil of the GM
Cytotoxic edema is primarily affecting:
astrocytes
Sudden reduction in plasma osmolarity that can create a temporary situation where the astrocyte cytoplasm is ______________ relative to plasma
hyperosmolar
The astrocytes can’t unload the idiogenic osmoles fast enough and as a result the cells take on water by osmosis. We have increase tissue water content and we refer to it as ___________
cytotoxic edema
Causes further tissue swelling, increased intracranial pressure, and further reductions in tissue blood flow that can result in damage to ion pumps of astrocytes giving rise to cytotoxic edema
(positive feedback loop)
vasogenic edema
You can initiate the edema cycle through __________ or ____________ edema
cytotoxic, vasogenic
In this case, both edema cycles were initiated
spongiosis
is caused by the rodenticide bromethylene
Intramyelinic Edema
The cause of death of this toxin is the increased intracranial pressure that is driven by the set of toxic edema. It is the myelin sheath swelling around intact axons that is key to making an ideological diagnosis based on postmortem examination.
Bromethalin toxicity
As pressure increases within the calvarium there is going to be the tendency of the brain to want to herniate or squeeze out the _____________ of the calvarium
caudal aspect
the occipital cortex is seen herniating under the tentorium cerebelli and the cerebellum is herniating into foramen magna.
Tissue death due to loss of blood flow is infarction and when that occurs in the presence of blood it is known as:
hemorrhagic infarction
If I were to compress the mesencephalic aqueduct, CSF continues to be produced proximal to that site because there’s no regulation of the rate of production and thus CSF pressure increases and it pushes across the epenymal cell lining of the ventricular system, entering into the periventricular WM.
Transependymal Edema
Enlarged Ventricles: What results in periventricular WM atrophy?
First fluid and WM seperates oliodendrocytes from astrocytes. So, there is gradual loss of myelin, resulting in periventricular WM atrophy
Intracranial pressure also reduces blood flow to gray matter, resulting in GM _______
atrophy
Enlargement of the ventricles is refered to as:
Hydrocephalus
A dog is hit by a car, and vascular damage has caused cerebral edema. The increase intracranial pressure has resulted in brain herniation and death. What type of edema is present at the time of death?
vasogenic and cytotoxic
The most significant finding was intramyelinic edema in the central nervous system. What is your top differential diagnosis?
ingestion of a rodenticide containing bromethalin
