Neuro 3 Flashcards
what does the term lissencephaly mean?
absence of normal gyri and sulci of the cerebrum, aka it’s a smooth brain
what are the names for a small brain cavity and a large brain cavity. what is a general cuase for these?
small=porencephaly
large=hydranencephaly
viral damage (like bluetongue, BVDV, etc)
what two virus types can cause cerebellar hypoplasia?
parvoviruses like canine parvo and feline panluekopenia
pestiviruses like BVDV and classical swine fever
both types target rapidly dividing cells (so it hits the cerebellum)
the most common CNS congenital anomaly is
hydrocephalus
what is hydrocephalus?
abnormal accumulation of CSF within the cranium
what is the cause of congenital hydrocephalus? which animals are predisposed to this?
secondary to in utero viral infection
- brachy breeds like chihuahua, bulldog, pug, yorkie, toy poodle, etc
what are the three types of hydrocephalus?
- congenital
- acquired
- hydrocephalus ex vacuo
what causes acquired hydrocephalus?
- some sort of obstruction (inflammatory blockage, infection, compression from a mass or abscess, etc)
what is hydrocephalus ex vacuo and what causes it
-aka compensatory hydroephalus, where the CSF replaces lost neural tissue
not related to CSF obstruction, but is actually an aging change or can also happen after radiation exposure
describe where fluid accumulation would be in each scenario regarding hydrocephalus if the bloackage were located:
- interventricular foramen between lateral and third ventricle
- blockage of mesencephalic aqueduct
- blockage of resorption of CSF
- unilateral dilation of affected lateral ventricle
- bilateral dilation of lateral ventricles, 3rd ventricle, and cranial part of mesencephalic aqueduct
- everything dilated!
what are some gross findings of hydrocephalus?
- if congenital, an enlarged domed skull with prominent fontanelles
- atrophy and loss of interventricular septum pellucidum
which breed of dog can have hydrocephalus but show no clinical signs?
toy breeds
what is occipital dysplasia?
common incidental finding in toy breeds where there is an underdeveloped occipital bone of the skul, resulting in a keyhole shaped foramen magnum. it does not cause clinical signs
what is this
occiptal dysplasia
listeriosis is caused by _________, and has 3 disease presentations which are:
listeria monocytogenes, gram +, small ruminants, zoonotic
- meningoencephalitis (adult animals)
- abortion/stillbirth (young animals)
- septicemia (young animals)
what is the pathogenesis of listeriosis in regards to meningoencephalitis?
- consumption of improerly prepared silage that contains high numbers of bacteria, trauma to the oral mucosa allows bacterial invasion, migration to trigeminal ganglia and then to the brainstem via retrograde axonal transport, leading to inflammatory damage in the brain
what are some clinical signs of listeriosis and histo lesions?
C/S: circling, twisted neck, dullness, padding
histo: microabscesses w neutrophils
histophilus comni, gram neg, causes what brain disease? in what animal is this most common?
thrombotic meningoencephalitis
feedlot cattle
what is the pathogenesis of thombotic meningoencephalitis?
uncertain, but we know it gains entry via resp tract and gains access to blood causing a septicemia. it damages the endothelial cells leading to thrombosis
what are some histo lesions for thrombotic meningoencephalitis
vasculitis, thombosis, and infarction
what causes pituitary abscess
bacteria, usually opportunistic
pathogenesis not fully understood, possibly extension from sinus or ear infection, or maybe due to the fact that there is delicate blood supply in that area
WOT
pituitary abscess (probably extension from sinuses, you can see pus there), suppurative sinusitis
Enterotoxiemia of sheep and goats is caused by ________. what is the pathogenesis? what is the lay term for this disease?
clostridium perfringens type D
- sudden change in the intestinal environent (like large amounts of grain), causes proliferation of the bacteria and production of the epsilon toxin, which damages endothelial cells and spreads via the blood
over eating disease
what is another name for enterotoxemia of sheep and goats?
focal symmetric encephalomalacia
if this is from a sheep that just ate a ton of grain and then suddenly died, what is this disease pobably?
focal symmetric encephalomalacia/entertoxemia of sheep and goats
you can see the symmetric hemorrhages in the brain
edema disease in pigs is caused by
E coli, shiga toxin producing, cuases vascular damage
who does edema disease usually target, and what lesions can you see on histo?
- the best of the herd, healthy feeder pigs
- vascular necrosis and bilaterally symmetric areas of malacia in the caudal medulla
a vareity of fungi can cause infection of the CNS, but usually sporadic and often secondary to
immunosupression
cats can get a fungal disease of the brain where there are cystic gelatinous lesions in the brain. what is this called and what causes it?
cryptococcosis caused by cryptococcus neoformans
this is a cat brain, what likely is this? what would be some histo findings of this case? What are you thinking predisposed this cat to getting this disease?
cryptococcosis caused by cryptococcus neoformans (or gatti)
you can see the cystic gelatinous lesions in the brain
histo: mild inflammation, can see the yeast sometimes (clear non staining capsule and narrow based budding)
I would go looking if this cat had FIV or FeLV since immunosupression can cause this
who is the definitive host for:
- toxoplasma gondi
- neospora caninum
toxoplasma: cats
neospora caninum: dogs
ruminants can be infected with toxoplasma gondi and neospora caninum. what does it cause?
non suppurative encephalomyelitis and polyraidculoneuritis (inflammation of nerve roots)
what causes nervous coccidosis of calves?
a unusual nervous presentation associated with intestinal coccidia infection (eimeria), common in calves 1 month to 1 year old, the calves hsow nerulogical signs but we have no idea why this happens
what is a nematode worm of racoons that is zoonotic? where do the larvae migrate to? what would be a histo lesion? who gets these besides racoons?
baylisascaris procynosis
larvae migrate to the brain and the eye
histo: eosinophilic encephalitis
dogs and birds get this from consumption of eggs from racoon feces and these eggs are very resistant!!!
canine distemper virus infects what tissues/cells, and targets what 3 systems?
- lymphoid and epithelial tissues/ macrophages
- lungs, GI tract, and CNS
what is the pathogenesis of canine distemper virus?
transmission via aerosol, initial replication in the lymph nodes causing immunosupression and secondary infections, leukocyte trafficking allows migration to the CNS and other epithelium
how do dogs with distemper virus often present?
rhinitis, conjunctivitis, and pneumonia
what are some clinical signs of canine distemper virus?
usually in puppies, fever, conjunctivitis, nasal discharge, vomiting, diarrhea, hyperkeratosis of the footpads and nose, enamel hypoplasia
what are some histo lesions of canine distemper virus?
demyelination (seen as white matter vacuolation)
intracytoplasmic AND intranuclear viral inclusion bodies
what causes equine encephalomyelitis?
arboviruses like West Nile virus transmitted via mosquitos or birds, causing a polioencephalomyelitis (grey matter)
what are the three key organs to west nile virus in birds?
brain, kidney, heart
give two examples of lentiviruses that are of importance and what 4 body systems they target
- caprine arthritis and encephalitis virus (CAEV) in goats
- maedni virus (MV) in sheep, causes ovine progressive pleuropneumonia
4 systems: CNS (non suppurative leukoencephalomyelitis), lung, joints (hygroma), mammary gland
how are small ruminant lentiviruses transmitted and what cells do they infect? how do they get to the CNS? what age is commonly affected?
transmission via milk/colostrum
infect monocytes/macrophages
get into CNS via leukocyte trafficking
usually causing disease in young goat kids, they will have neurologic disease and may have penumonia as well
this disease targets the white matter (demyelination)
