Neuro - Infectious/Non-Infectious Inflam Dz Flashcards
Know the four routes by which pathogens invade CNS.
direct extension/implantation
hematogenous
peripheral nerves
leukocyte trafficking
Discuss the most common pathogenesis associated with meningitis and the typical gross lesions
systemic bacterial infection (septicemia) - common in neonatal septicemia
opaque leptomeninges (ventral aspect)
Describe the CNS lesions that can be seen secondary to otitis media/interna and sinusitis
inner/middle ear = cerebellopontine abscess
cribiform plate/sinusitis = frontal abscess due to oestrus ovis
what bacteria commonly causes cerellopontine abscesses in cattle
Mycoplasma bovis
pathogenesis of listeria monocytogenes
Associated w/ spoiled silage
Oral wound allows bacterial invasion of mucosa → bacteria invade trigeminal n. → travel to brainstem via axons (retrograde)
lesions of listeria monocytogenes
No gross lesions
Microabscesses in brainstem (pons and medulla)
pathogenesis of histophilus somni
Respiratory tract → septicemia → thrombotic meningoencephalitis
lesions of histophilus somni
multifocal hemorrhages and malacia
vasculitis
Describe the pathogenesis and CNS lesions associated with C. perfringens type D
Epsilon toxin
focal symmetrical encephalomalacia (FSE)
degeneration of vascular endothelial tight junctions → leakage of fluids → increased intracerebral pressure → parenchymal necrosis
gross and microscopic findings of viral infections
no gross lesions
most prominent in the gray matter
non-suppurative inflam
perivascular cuffs, mild meningitis, glial nodules, neuronophagia
causes of encephalitis in horses
EHV-1
equine encephalitis virus (eastern, western, venezuelan)
west nile
rabies
what is unique about EHV-1 causing myeloencephalopathy
does not specifically target gray matter - random asymmetrical foci of hemorrhage
viruses that cause demyelination
canine distemper
small ruminant lentiviruses:
caprine arthritis-encephalitis virus (goats)
visna (sheep)
lesions associated with FIP
meningitis/ventriculitis
granulomatous & exudative ventriculitis/periventricular encephalitis
viral inclusions of rabies
intracytoplasmic “negri bodies”
viral inclusions of canine distemper
intracytoplasmic & intranuclear
viral inclusions of pseudorabies (herpesvirus)
intranuclear
characteristics of fungal/algae infections
gross lesion?
histo lesions?
opportunistic
parenchymal discoloration or “mass like”
renchymal discoloration or a “mass-like” lesion
granulomatous/pyogranulomatous inflammation, presence of organisms
pathogenesis of feline cryptococcosis
inhalation into nasal cavity → invasion through cribiform plate or along olfactory n → meningoencephalitis
what does sarcocytis neurona cause? lesion?
equine protozoal myeloencephalitis (EPM)
asymmetrical foci of hemorrhage and malacia
signalment and lesions of neospora caninum
young dogs (in-utero infection)
polyradiculoneuritis
polymyositis
characteristics of protozoal infections
pyogranulomatous/granulomatous inflam +/- eosinophils & presence of organisms
characteristics of parasitic infections
Granulomatous and/or eosinophilic inflammation
Linear tracts of hemorrhage and necrosis
Organisms present (larvae or adults)
cestode larva can infect the CNS of who? what do cestodes cause?
intermediate hosts
single or multiple cysts (space occupying lesions)
