Neuro - Infectious/Non-Infectious Inflam Dz

Question 1

Know the four routes by which pathogens invade CNS.

Answer 1

direct extension/implantation
hematogenous
peripheral nerves
leukocyte trafficking

Question 2

Discuss the most common pathogenesis associated with meningitis and the typical gross lesions

Answer 2

systemic bacterial infection (septicemia) - common in neonatal septicemia

opaque leptomeninges (ventral aspect)

Question 3

Describe the CNS lesions that can be seen secondary to otitis media/interna and sinusitis

Answer 3

inner/middle ear = cerebellopontine abscess

cribiform plate/sinusitis = frontal abscess due to oestrus ovis

Question 4

what bacteria commonly causes cerellopontine abscesses in cattle

Answer 4

Mycoplasma bovis

Question 5

pathogenesis of listeria monocytogenes

Answer 5

Associated w/ spoiled silage
Oral wound allows bacterial invasion of mucosa → bacteria invade trigeminal n. → travel to brainstem via axons (retrograde)

Question 6

lesions of listeria monocytogenes

Answer 6

No gross lesions
Microabscesses in brainstem (pons and medulla)

Question 7

pathogenesis of histophilus somni

Answer 7

Respiratory tract → septicemia → thrombotic meningoencephalitis

Question 8

lesions of histophilus somni

Answer 8

multifocal hemorrhages and malacia
vasculitis

Question 9

Describe the pathogenesis and CNS lesions associated with C. perfringens type D

Answer 9

Epsilon toxin
focal symmetrical encephalomalacia (FSE)

degeneration of vascular endothelial tight junctions → leakage of fluids → increased intracerebral pressure → parenchymal necrosis

Question 10

gross and microscopic findings of viral infections

Answer 10

no gross lesions
most prominent in the gray matter
non-suppurative inflam
perivascular cuffs, mild meningitis, glial nodules, neuronophagia

Question 11

causes of encephalitis in horses

Answer 11

EHV-1
equine encephalitis virus (eastern, western, venezuelan)
west nile
rabies

Question 12

what is unique about EHV-1 causing myeloencephalopathy

Answer 12

does not specifically target gray matter - random asymmetrical foci of hemorrhage

Question 13

viruses that cause demyelination

Answer 13

canine distemper

small ruminant lentiviruses:
caprine arthritis-encephalitis virus (goats)
visna (sheep)

Question 14

lesions associated with FIP

Answer 14

meningitis/ventriculitis
granulomatous & exudative ventriculitis/periventricular encephalitis

Question 15

viral inclusions of rabies

Answer 15

intracytoplasmic “negri bodies”

Question 16

viral inclusions of canine distemper

Answer 16

intracytoplasmic & intranuclear

Question 17

viral inclusions of pseudorabies (herpesvirus)

Answer 17

intranuclear

Question 18

characteristics of fungal/algae infections
gross lesion?
histo lesions?

Answer 18

opportunistic

parenchymal discoloration or “mass like”
renchymal discoloration or a “mass-like” lesion

granulomatous/pyogranulomatous inflammation, presence of organisms

Question 19

pathogenesis of feline cryptococcosis

Answer 19

inhalation into nasal cavity → invasion through cribiform plate or along olfactory n → meningoencephalitis

Question 20

what does sarcocytis neurona cause? lesion?

Answer 20

equine protozoal myeloencephalitis (EPM)

asymmetrical foci of hemorrhage and malacia

Question 21

signalment and lesions of neospora caninum

Answer 21

young dogs (in-utero infection)

polyradiculoneuritis
polymyositis

Question 22

characteristics of protozoal infections

Answer 22

pyogranulomatous/granulomatous inflam +/- eosinophils & presence of organisms

Question 23

characteristics of parasitic infections

Answer 23

Granulomatous and/or eosinophilic inflammation
Linear tracts of hemorrhage and necrosis
Organisms present (larvae or adults)

Question 24

cestode larva can infect the CNS of who? what do cestodes cause?

Answer 24

intermediate hosts

single or multiple cysts (space occupying lesions)

Question 25

types of canine meningoencephalitis of unknown origin (MUO)

Answer 25

granulomatous meningoencephalitis
necrotizing mengioencephalitis
necrotizing leukoencephalitis

Question 26

canine meningoencephalitis of unknown origin (MUO) is thought to do what? signalment? distribution?

Answer 26

immune mediated
young small breed dogs
multifocal

Question 27

signalment of steriod-responsive meningitis-arteritis (beagel pain syndrome)

Answer 27

young adult dogs with acute fever, neutrophilia and neck pain