Neuro - Toxins & Degenerative Disease Flashcards
what are common diagnostic features of toxic/metabolic diseases
bilateral, symmetric
specific anatomic areas or cell types in the CNS
what are the 4 main causes of polioencephalomalacia in ruminants “cerebrocorticol necrosis”
sulfur toxicity
thiamine deficiency
water deprivation encephalopathy/salt poisoning/water intoxication
lead toxicity
MOA of sulfur toxicity
H2S decreases mitochondrial respiration (inhibits cytochrome oxidases) resulting in neuronal dysfunction, degeneration and necrosis
MOA of thiamine deficiency
increased lactate and subsequent ruminal acidosis
high carb diet results in an overgrowth of thiaminase producing bacteria (Clostridium sporogenes and Bacillus thiaminolyticus)
what are the gross findings with polioencephalomalacia in ruminants “CCN”
deep laminar necrosis resulting in perisulci cystic cavities
what diagnostic can you use for polioencephalomalacia
UV light/wood’s lamp - will identify macrophages that ingested pigment (lipofuscin)
histologic findings with polioencephalomalacia in ruminants “CCN”
neuronal necrosis - band-like (pseudo) laminar
salt toxicity (water deprivation encephalopathy) is most common in what species due to what
pigs
water intake restriction while being fed a high salt diet = hypernatremia
what histologic findings are found with water deprivation encephalopathy
eosinophilic perivascular infiltrates (pathognomonic)
how does thiamine deficiency (B1) of carnivores differ from that of PEM/CCN of ruminants
carnivores are dependent on dietary intake of thiamine
topography and nature of lesions is different
carnivores - caudal colliculi, medial vestibular nuclei & lateral geniculate bodies
ruminants - cerebrocortical
cause of equine nigropallidal encephalomalacia? what is the suscpected toxic compound? lesion?
ingestion of yellow star thistle or russian knapweed
repin
bilaterally symmetrical malacia of substantia nigra and globus pallidus
what cause equine leukoencephalomalacia
ingestion of moldy corn contaminated with Fusarium moniliforme (fumonisin B1)
bilaterally ASYMMETRICAL
spongiform encephalopathy pathogenesis
normal protein (PrPc) exposed to scrapie protein (PrPSc) = served as a template to influence a geometric conformational change in the produced by exposed animal
equine degenerative myeloencephalopathy etiology
hereditary defect that predisposes to pathology related to environmental or nutritional factors (vitamin E deficiency)
what sample do you send for spongiform encephalopathy
medulla oblongata - obex
