68- Nervous System, Inflamm Conditions

cerebral abscesses are from?

direct extension or hematogenous spread from ventriculitis or leptomeningitis

sequelae of cerebral abscesses

depending on size and location, can compres/displace tissue and vital structures like cardiac or resp centers

what is choroid plexitis/ependymitis?

invasion of bacteria in the choroid plexus/ependymal lining resulting in inflammation

what can happen with severe choroid plexitis?

the inflammation can transverse the fourth ventricle and spread thru the subarachnoid space causing suppurative leptomeningitis

gross lesion of choroid plexitis/ependymitis

gray/white to yellow/green thick to gelatinous CSF within ventricular system

choroid plexuses may be granular and gray/white with hyperemia and hemorrhage

what is meningitis most commonly caused by?

bacteria that reach the leptomeninges and subarachnoid space hematogenously

t or f: strict viral leptomeningitis is rare

true

what commonly causes neonatal septicemia?

systemic bacterial infections are a common cause of acute meningitis

gross appearance of neonatal septicemia

diffuse to focal cloudiness or opacity in the leptomeninges

common cause of listeriosis?

contaminated silage seen in domestic ruminants

histo of listeriosis

microabscesses in brain stem, white/gray matter

gross lesions of listeriosis

usually absent

leptomeningeal opacity, foci of yellow/brown discoloration of cranial nerves with cloudy CSF

what is thrombotic meningoencephalitis?

dz that results in septicemia in cattle 6-12 m of age caused by histo. somni

clinically: ataxic, circling, head pressing, appear blind

gross lesions of thrombotic meningoencephalitis

random irregularly sized foci of hemorrhage and necrosis, most freq in cerebrum at the cortical grey-white matter interface

what is overeating disease?

brain damage from vascular injury and breakdown of BBB in goats and sheepw

what is overeating dz trigged by

sudden change in diet causing microflora imbalance and clostridial proliferation

gross lesion of overeating disease

bilaterally symmetric foci of malacia and cavitation

what is granulomatous meningoencephalitis?

idiopathic condition in young to middle aged small breed dogs

gross lesions of granulomatous meningoencephalitis

rarely causes grossly visible masses but if present irregular grey/white to red areas in the white matter, most severe in brainstem

histo of granulomatous meningoencephalitis

perivascular cuffs of macrophages and lymphocytes with a few plasma cells

histo of rabies

leptomeningitis with perivascular cuffing by lymphocytes, macrophages, and plasma cell

what are the eosinophilic intracytoplasmic inclusions found on rabies histo called?

negri bodies

how does equine encephalomyelitis occur?

via a vector

primary target cell of equine encephalomyelitis

neuron

what do all 3 viruses of equine encephalomyelitis induce?

polioencephalomyelitis

where does equine encephalomyelitis cause inflammation?

in gray matter

what is more likely to occur with west nile virus than with equine encephalomyelitis?

hemorrhage

what does equine herpesvirus cause grossly?

vasculitis affecting small blood vessels with thrombosis and focal CNS necrosis (characteristic lesion)

what is malignant catarrhal fever?

sporadic highly fatal viral dz of cattle and other ruminants

how is caprine arthritis encephalitis transmitted?

thru colostrum /milk or direct contact

gross lesions of caprine arthritis encephalitis

leukoencephalomyelitis in goats

how is canine distemper spread?

via aerosol

describe the histo of canine distemper

its not common to see, but could see necrosis in grey and white matter of brain and spinal cord

what occurs with canine herpesvirus-1?

systemic infection in young puppies that can lead to CNS infection

histo of FIP

pyogranulomatous nodules with vasculitis

most fungal infections represent what?

opportunistic pathogens that primarily affect immunocompromised hosts.

how does cryptococcus enter the body?

enters the leptomeninges by direct extension thru the cribriform plate after nasal or sinus infection

crypto secretes a ___ complex polysaccharide capsule that protects the fungus from host defenses

thick

gross lesions of crypto

mult small cyst like structures with a viscous gelatinous appearance in the leptomeninges and CNS

what does neosporosis cause?

multifocal necrotizing lesions with glial nodules and mixed inflammatory infiltrates causing neuro disease

neosporosis gross lesions

hemorrhage or necrosis, yellow/brown granular texture & can involve white or gray matter

describe toxoplasmosis

in utero infections that can lead to CNS infection

nerve roots can be involved

foci of hemorrhage and necrosis which may progress to granular yellow-brown to fray foci

EPM is most commonly caused by

sarcocystic neuronaa

cuterebra spp in small animals, rabbits, and rodents invade what in cats in dogs?

brain

oestrus ovis develops in the ____ of sheep

nasal cavity

hypoderma bovis enters where with cattle and water buffalo?

spinal canal during their migration in the subcutis

feline ischemic encephalopathy gross lesions

often unilateral in white and gray