Neuropathology Flashcards
enterotoxemia in small rums (pulpy kidney dz) cause, path, lesions
- Clostridium perfringens type D epsilon toxin destroys blood-brain barrier → edema → ischemia & infarction
- gross = bilateraly symmetrical malacia
- non CNS = pulmonary congestion & edema, pericardial effusion, pulpy kidney
edema dz in pigs: cause, path & lesions
- genetic predisposition + E. coli shiga-toxin = endothelial damage (fibrinoid necrosis) → edema → ischemia & infarct
- bilaterally symmetrical malacia in terminal brainstem, dramatic edema in brain & other organs
hepatic dysfxn leads to neuro dz d/t accum of neurotox metabolic end-products such as 4
- ammonia
- mercapens
- GABA
- glutamine
polioencephalomalacia lesions
cerebrocorticol gray matter that autofloresce under 375 nm UV (pathognomic)
• gross: brain swollen (flat gyri, narrow culci) w yellow discoloration (necrotic parynchema)
• micro: laminar pattern of neuronal necrosis & edema, influx of monocytes in perivascular & perineuronal areas
canine distemper: cause, path, lesions, sequelae
- pantropic virus w affinity for CNS, epithelium & lymph
- reach brain via blood monocytes → infxn of ependymal & periventricular locations → replicates in astrocytes (intranuclear inclusions)
- neuronal necrosis, nonsuppurative meningoencephalitis, progressive demyelination
- old-dog encephalitis/hard-pad dz
rabies: cause, path, lesions
- neurotropic Lyssavirus
- bite from infected animal → moves along peripheral nn. to brain & spinal cord
- nonsuppurative meningoencephalitis, neuronal degeneration, vacuoles in cerebral cortex & thalamus – may include Negri bodies (inclusions) in cerebellum & hypocampus
causes of 2 types of TSE
- white matter (myelinic) – hepatic or renal encphalopathis, toxicosis, idiopathic in Herefords.
- gray matter (nonmyelinc) – prion dz (ex: scrapie), idiopathic in Angora oats & bull-mastiffs
thromboembolic meningoencephalitis (TEME) in bovine: cause, path, lesions
- H. somni enters bloodstream from GI → septicemia → vasculitis & vascular necrosis
- suppurative-pyogranulomatous encephalitis, purulent leptomeningitis (associated: myocarditis)
listeriosis in cattle: cause, path, lesions
- Listeria from incompletely fermented silage
- axonal spread to trigeminal & facial nn., brainstem → paralysis of medullary centers → circling dz!
- often no gross → meningoencephalitis (also abortion/stillbirth & septicemia in young) … histo = perivascular cuffing, microabscesses in brainstem
IVDD lesions
- gross: hemorrhage & malacia (d/t ischemia & hypoxia)
- micro: necrosis of gray & white matter, axonal injury & Wallerian degen, disruption of myelin sheaths
fibrocartilaginous embolic myelomalacia: what is it, predisposing factors & pathology
peracute neuro condition in dogs:
• non-chondrosyplastic lg breed dos (associated w type II herniation)
• fibrocartilaginous material from nucleus pulposus travels to different lvls of spinal cord → infarction
EPM lesions
necrosis & nonsuppurative inflam (both gray & white matter) in cervical & thoracic spinal cord, perivascular cuffing of lymphocytes & plasma cells
lethal white syndrome: cause, lesions
- homozygous dz in paint (overo & sabino) horses’ endothelin-B receptor
- absence of myenteric & submucosal plexuses → functional blockage of colon
dysautonomia: cause in horses, CS, 1° & 2° lesions
- horses: acute or chronic stasis (Clostridium botulinum type C?)
- CS: GI disturbances, urinary incontinence, mydriasis, bradycardia, megaesophagus
- 1°: no gross, histo = neuronal degen & necrosis, mild lymphocytic inflam in peripheral & autonomic gangli & nuclei in brainstem
- 2°: aspiration pneumonia (from megaesophagus), 2° lesions d/t GI stasis
3 nutritional dz of eye (w path)
- vit A: night blindness
- vit E or C: hyperreflectivity of tapetum lucidum
- taurine: progressive degen of photoreceptor (esp. cones)
