Smith 5 - Neuro Flashcards
where is CSF produced
choroid plexuses of the lateral, third, and fourth ventricles
ependymal lining of the ventricular system
Pia arachnoid
meningeal blood vessels
alpha viruses
EEE / WEE / VEE
- EEE worst, more severe and rapid progression
- young horses more susceptible
“East is the beast”
EE signs
1) inapparent infection, low grade viremia and fever = initial viremia
2) fever, anorexia, depression, tachycardia, D+ = viral proliferation
3) clinical encephalomyelitis
CSF in EEE
moderate neutrophilic or lymphocytic pleocytosis
Getah / Ross River Virus
- mosquito transmitted
- fever, edema, urticaria 7-10 days
- fever, lameness, swollen joints
- orient / South Pacific / australia
Borna disease
- viral encephalitis in Europe
- horses and sheep, spring and summer
- forebrain signs, followed by brainstem and SC, die in 1-4 weeks
Henipavirus
- australia
- widespread vasculitis, endothelial syncytial, vascular thrombosis, hemorrhage, cellular necrosis
bunyaviridae
may cause acute encephalitis
equine encephalosis
- arthropod borne virus
- mild or subclinical dz
- culicoides
west nile
- flavivirus
- cycles between mosquito vectors and avian reservoir hosts
- cluex vectors
- varied signs; fever, ataxia, weakness, muzzle fasciculations, twitching cutaneous muscles of torso and neck
CSF in WNV
mild to moderate mononuclear pleocytosis, low numbers of neutrophils
traumatic optic nerve damage
- stretching of the optic nerves
- sudden blindness, loss of PLRs, dilated pupils
- will progress after injury, no tx
equine thiamine deficiency
- diet containing thiaminase
- bracken fern, horsetails
- ataxia, blindness, CP deficits, bradycardia / blocking
equine leukoencephalomalacia
- fumonisin toxins from fusarium fungi in corn
- sudden death
- sudden onset obtundation, circling, head pressing, blind, ataxia, asymmetric fasciculations
- liquefactive necrosis of cerebral hemispheres
cholinesteric granuloma encephalopathy
- choroid plexuses of the 4th ventricles and lateral ventricles
- chronic inflammatory reaction to cholesterol from extravasated degenerating RBCs
- forebrain signs
border disease
hairy shakers
- pestivirus
- hypomyelination
encephalitic bovine herpes
BoHV-1,5
-depression, nasal / ocular discharge, CP deficits, head pressing, circling, bellowing, drooling, bruxism, tongue paralysis, head tilt, nystagmus, convulsions, blindness, coma, death, fever
BSE
- transmissible spongiform encephalopathy
- prion
- occurs in 4-6yo cattle
- always fatal
scrapie
TSE in sheep and goats
pseudorabies
aujeszky’s dz
- acute, severe, fatal encephalitis
- varicellovirus
louping ill
ovine encephalomyelitis
- tick spread
- yearling sheep in the spring
- fever, anorexia, depression, constipation, and generalized muscle tremors
rabies
- lyssavirus
- acute and progressive
- dysphagia, hydrophobia, paresis, paresthesia, salivation, febrile, tenesmus
buss disease
sporadic bovine encephalomyelitis - chlamoydophila pecorum
- multisystemic dz
- can resemble hardware dz
oxygen tx
causes of brain abscesses
horses - strep equi
cattle - t. pyogenes
nervous coccidiosis
-calves and yearling cattle, sheep, goats
- feedlots NW US / Canada
- D+, tenesmus, hematochezia, depression, incoordination, twitching, recumbency, nystagmus
Tx: sulfmethoxine
sarcocystis infections
cattle goats and sheep
-dogs are the definitive host
Babesia encephalitis
acute encephalitis with fever
erlichia ruminatium
fatal encephalitis in goats, sheep, and cattle
polioencephalomalacia
excess sulfur, altered thiamine metabolism, salt poisoning, or water deprivation, amprolium toxicity, lead toxicity
vitamin A deficiency
growing ruminants in feedlots (lack of green plants)
- stargazing, blindness, diarrhea, short seizures , ocular changes
- dilated unresponsive pupils
hydranencephaly
normotensive hydrocephalus
- failure of cell growth or cellular necrosis
- viral pathogens in utero
hypertensive hydrocephalus
increased CSF volume from compressive or obstructive lesions
-can be congenital
ammoniated forage toxicosis
cow bonkers
- acremonium fungus in fescue
- hyperesthetic and ataxic, sawhorse stance at rest, excitable when alert
- recurrent mania episodes
lead poisoning in ruminants
acute encephalopathy
-blindness, ataxia, depressed sensorium
lead poisoning in horses
chronic polyneuritis
-weight loss, dysphagia, aspiration pneumonia
lead poisoning treatment
- chelation with calcium EDTA for 5 days
- thiamine
sheep gid
coenurus cerebral infestation (larval stage of tenia multiceps)
-larval migration causes signs - brain or SC
- Tx: praziquantel if no neuro signs, NSAIDs, dex, surgical removal
ceroid lipofucinosis
lysosomal storage disease - inherited
- progressive, fatal dz
peripheral vestibular dz in horses
- many causes
- acute, asymmetric
- head tilt towards affected side, nystagmus with fast phase away from affected side, circling to affected side
- signs much worse w blindfold
- visual accommodation can occur and may return to work
star thistle / knapweed poisoning
centaurea solstitalis
thaponticum repens
equine nigropallidal encephalomalacia
- adult horses
- facial and lingual dystonia, variable obtundation, behavioral signs, ataxia
THO
- periosteal reaction and enlargement of the stylohyoid, tympanic bulla, and petrous portion of the temporal bone
- sudden onset asymmetric CN signs, facial muscle degeneration, recused tear film
listeria
- multifocal brainstem disorder, diffuse meningoencephalitis, or myelitis
- asymmetric signs, CP deficits, head pressing, CN deficits V-XII
CN VIII lesions
nystagmus that changes w head position
path diagnosis of listeria
- multifocal brainstem micro abscesses
- isolate agent from nervous tissue NOT CSF
Histophilus somni
Thromboembolitic meningoencephalitis
Sleeper Calves
- neuro dz that can arise from septicemia; infected via resp tract
- can infect multiple organs
- frequent outbreaks in feedlot cattle
- causes apoptosis of endothelial cells; micro thrombi in brain stem, SC, synovial membranes, pleurae and lungs
- bacterial colonies in thrombosed vessels on histo
- thrombus forms at site of vascular lesion - not a true embolism!
CS associated with lesions in cerebellum and caudal brainstem
head tilt, nystagmus, strabismus, blindness, muscular tremors, opisthontos, coma, convulsions
otitis media / interna
- cattle and sheep
- secondary to resp infections; ascending infection from pharynx to Eustachian tube
- unilateral peripheral vestibular dz
- head shaking, ear droop, head tilt to side of lesion, nystagmus (fast away from lesion), stumbling and circling
cattle ear mite
raillietia auris
-can perforate tympanum and cause vestibular dz
small ruminant ear mite
psoroptes cuniculi
cerebellar abiotrophy
- arabian and pony foals
- simple autosomal recessive
- genetic mutation causes degeneration
- decreased MUTHY - encodes DNA glycosylase that repairs oxidative damage to DNA
CS of cerebellar abiotrophy
- age 3mos
- incoordination, base wide thoracic limbs, head tremors esp when nursing
- no menace, ataxia
- exaggerated when stimulated
BVD can cause cerebellar hypoplasia when
cows infected from 90-170d of gestation
lavender foal syndrome
- arabian
- dilute coat color
- episodes of opisthontos, hyper response to touch, limb paddling, uncontrolled eye movements
- cannot even get to sternal
- can vocalize and have a strong suckle
- MYO5A gene mutation
lethal white foal syndrome
- overo paint foals
- intestinal anganlionosis
Locoweed plants
astragalus
oxytropis
-indolizidine alkaloid swainsonine (aka locoine)
locoweed poisoning
- acquired neurovisceral storage disease
- hot dry weather and scarce forage
- ataxic and obtunded episodes alternating with mania
- high step gait, head tremors, flaccid nose and lips, dysphagia
perennial ryegrass staggers
endophyte (neotyphodium lolii) infected ryegrass (Lolium perenne)
- tremorgens, ergopeptides, and peramine
- coarse fasciculations and tremors of skeletal muscles, truncal sway, stumbling
paspalum staggers
- ergots = claviceps papsali
- grass = paspalum
bermuda grass staggers
-grass = cynodonts dactylon
canary grass staggers
phalaris
ceroid lipofuscinosis
progressive ataxia, blindness, depression, coma
-autosomal recessive
citrullinemia
- newborn holsteins
- depression, bellowing, abnormal tongue and face movements, convulsions, death
alpha mannosidosis
- cattle 1wk - 15 mos
- stunted growth, ataxia, head tremor, hypermetria
beta mannosidosis
- newborn cattle and goats
- recumbency, deaf, narrow palpebral fissures, intention tremor, deformities
inherited myoclonus
- Paso finos
- GABA receptor deficiency
- hopping newborns
EHV-1 EHM
- acute onset ataxia and tetraparesis
- biphasic fever before neuro signs
- truncal ataxia and paresis, bladder distention, incontinence, weak tail and anus
EHV-1 CSF
- xanthrochromic
- high protein
- normal NCC
EPM treatments
- sulfadiazine/pyrimethamine = folate inhibitor
- ponazuril / diclazuril = coccidiostat
EDM
- neuroaxonal dystrophy
- equine degenerative myeloencephalopathy
- poor hay / no grass access
- low Vit E
- symmetric ataxia and paresis, pacing, NO MUSCLE ATROPHY
- age of onset 1-12 months
verminous meningoencephalomyelitis
- strongylus vulgaris
- angiostrongylus cantonensis
- p. tenuis
- hypoderma
p. tenuis
- white tailed deer
- larvae mature in SC before traveling to brain
- cervids, goats, sheep, camelids
- no tx
spinal cord abscesses
-come from vertebral body osteomyelitis
sorghum toxicity
- ataxia, incontinence, and cystitis
- horses, cattle, sheep
Lesions located at T3-L3 cause?
- Pelvic limb paraparesis and ataxia
- Doesnt affect forelimbs
- urinary bladder is normal
Lesions located at L3 to S2 cause?
- hind limb paraparesis or paraplegia
- may be urine scalding
____________ in cattle occurs primarily in young growing animals 6–9 months of age on concentrate rations and is characterized clinically by a sudden onset of blindness, muscular tremors of the head and neck, head-pressing, nystagmus, and opisthotonus. The disease also occurs in mature beef cattle on pasture containing a high level of sulfate in their water and feed.
Polioencephalomalacia
___________ is most common in calves after spring turnout, but occurs in adult cattle too, and is characterized by central blindness, tremors, convulsions, uncontrollable activity with bellowing, champing fits, hyperexcitability, rumen stasis, and death in several hours. Early treatment may be successful.
Acute lead poisoning
_____________ in cattle is characterized by blindness, stupor, head-pressing, rumen stasis, weak palpebral reflexes, and no response to therapy.
Subacute lead poisoning
____________ in cattle is characterized by a history of a ____________ deficient diet and nyctalopia, peripheral blindness, dilated and f ixed pupils, optic disc edema, and transient convulsions followed by recovery.
Hypovitaminosis A
vitamin A
____________ in cattle is characterized by sudden onset of ataxia, recumbency, fever, depression with eyes closed, lesions of the fundus, marked changes in hemogram, enlarged joints, and death in several hours if not treated early.
Histophilus somni meningoencephalitis
in unvaccinated sheep, especially feedlot lambs, in which the clinical findings are almost identical; it occurs under the same management conditions as polioencephalomalacia.
___________ in lambs usually develops within several days after being placed on a grain ration, whereas polioencephalomalacia occurs after several weeks of grain feeding. Glycosuria may assist the diagnosis, but a necropsy is usually more informative
Enterotoxemia (pulpy kidney disease) caused by Clostridium perfringens type D
____________ in sheep also resembles polioencephalomalacia but is sporadic, usually involves only a few animals, and will not respond to treatment.
Focal symmetric encephalomalacia
test for scrapie
IHC test on the obex of the brain
—confirmatory test at some laboratories of the OIE
—gold standard test in the United States.
Clinical signs in BSE
Change in temperament and behavior Apprehension, excitable, unusual kicking, head-tossing when haltered, separation from group Change in posture and movement Abnormal posture and ataxia Fall in milk production
antemortem tests for BSE
none
3 month old goat kid, normal mentation, asymmetric weakness worse in HLs, proprioceptive abnormalities
CAEV leukoencephalomalacia
CAEV control
regular testing - elisa or agid q6mos and cull
pasteurize all milk
separate all kids at birth
Damage to the _____ nerve results in rear limb weakness and knuckling of the fetlocks;
sciatic
_______ nerve paralysis should be used for postparturient cattle with an inability to adduct one or both hindlimbs
obturator
________ nerve paralysis in calves occurs in large calves born to heifers with dystocia. T he injury occurs when calves in anterior presentation fail to enter the birth canal because their stifle joints become engaged at the brim of the pelvis.
Femoral
trismus with restriction of jaw movements; prolapse of the third eyelid; stiffness of the hindlimbs causing an unsteady, straddling gait; and the tail is held out stiffly
tetanus
pasture-associated stringhalt
pelvic limb hyperflexion
presumably progressive degeneration of large myelinated axons in tibial and peroneal nerve branches, including α motor neurons to skeletal muscle, 1A and 1B sensory neurons from muscle spindles, and Golgi tendon organs.
toxic cause of pasture associated stringhalt
dandelion
Central Blindness
Dorsomedial strabismus
Opisthontos
Lead or polio
