Rumi Neuro 2

sihirlifil's version from 2018-04-06 16:05

Cerebellar Disease

Question Answer
Examples of cerebellar dzsCerebellar hypoplasia
Staggers (grasses)
Storage diseases
CS of cerebellar dzCP deficits
Head tremor
Cerebellar hypoplasia: etiology? how does it happen?BVDV
CNS lesions at 90-170d of gestation: cerebellar hypoplasia, hydrancephaly, hydrocephalus, hypomyelinogenesis
What’s happening?
Cerebellar hypoplasia (BVDV)
Cerebellar hypoplasia: when will CS occur?(truncal ataxia, base wide stance, intention tremors, hypermetria…) Present at birth! Happens from natural infection or vax w/ MLV
Cerebellar hypoplasia: Dx?CS
Virus neutralization: antibodies present in precolostral blood
NOT persistently infected = infected AFTER the critical time! (antibodies not produced in PI calves!)
Tx/prognosis of cerebellar hypoplasiaOften not compatible with life
Which dzs produce cerebellar lesions in calves, camelids, & lambs?Border dz (sheep), bluetongue virus

Spinal Cord Disease

Question Answer
CS of spinal cord dzVary with location! (see other cards)
CS of spinal cord dz: Cervical?Weakness, incoordination, ataxia
CP deficits
Hyperreflexia in all legs (RL worse than front)
Respiratory & cardiac arrest
Stiff neck, refuse to lower/turn head
CS of spinal cord dz: Thoracic?Weakness in front legs
Hyperreflexia, incoordination, ataxia in hind legs
If sternal, HL extended instead of tucked (dog-sitting posture)
CS of spinal cord dz: Lumbar?Normal FL
Hyperreflexia, incoordination, ataxia in hind legs
Abnormal urination & defecation control
CS of spinal cord dz: Sacral?Normal FL
Weakness in HL
Flaccid tail & anal tone
Abnormal urination & defecation control
Spinal injuries: causes?
Trauma, abnormal bone mineralization, LSA, abscess
Spinal injuries: who is prone?Neonates! 2ry to bacterial inxn, nutritional deficiencies (Ca, Cu, Vit D)
Spinal injuries: common sitesC2-C4
Spinal abscess: how do they happen?Mainly pre-existing vertebral body abscesses: FPT neonates, endocarditis, septic injection sites

Spinal abscess: CS?(Similar to spinal fracture, vary w/ site)
Spinal abscess: DxPE
Rads, CT, MRI, myelogram
Spinal abscess
Spinal abscess: what does CSF analysis look like?Acute: Incr RBC, WBC, protein
Subacute: Xanthochromia, incr protein
Spinal abscess: prognosisGenerally poor… dx late in disease
Spinal abscess: TxAnti-inflammatories, long term antibx, supportive
Depends on size & intended use: confinement, sx (not usually)
Tick paralysis: which one usually responsible? how?Mainly Female Dermacentor ticks, all life stages. Neurotoxin in saliva blocks ACh release at neuromuscular jxn. ONLY TAKES 1!
Tick paralysis: CSAscending flaccid paralysis
Increasing stumbling & weakness, appetite --> respiratory failure, increasing recumbency --> death
Can have >1 animal affected
Ddx for tick paralysisP. tenuis
Heat stress
Trauma, tumor…
Tick paralysis: DxTick search (make yr vet students do it lol)
Shear to find ticks
Tick paralysis: TxInjectable ivermectin
Supportive… prognosis worsens w/ duration or recumbency. can take 2-3 days to recover even if caught early
Tetanus: etiology? which toxins involved?Clostridium tetani
Tetanospasmin, tetanolysin, nonspasmogenic toxin
Tetanus: when does it occur?Metritis (cattle)
Tail docking
Shearing wounds
Tetanus toxins: Tetanospasmin does what?Inhibit GABA release --> disinhibition of motor neurons --> tetanic muscles
Tetanus toxins: Tetanolysin does what?Necrotizing toxin, spread locally in tissues --> “nice” anaerobic environment
Tetanus toxins: Nonspasmogenic toxin does what?Overstimulation of SNS --> Hyperextension (catecholamine induced)
Tetanus: CS(Incubation 2-4w, CS persist ~1m due to irreversible binding to interneurons)
Anorexia, decreased rumen activity
Muscle stiffness, rigidity, sawhorse stance
Retraction of eye, flashing 3rd eyelid
Tetanus: DxHx, suspicion
Culture or gram stain
Tetanus: txTetanus antitoxin: neutralize unbound toxin
Debridement, penicillin: elim infxn
Supportive: quiet dark area, ear plugs; Muscle relaxation (ace, diazepam); good footing, maintain nutrition & hydration
Tetanus: prognosisFair-poor
Tetanus: preventionHusbandry, hygiene, prevent metritis in cows (most bovine vax don’t contain tetanus!)
Vas: tetanus toxoid. Antitoxin in at-risk animals

Peripheral Nerve Disease

Question Answer
How is peripheral nerve dz defined?Lack of sensory or motor response, depends on lesion localization
Common peripheral nerve paralyses (8)Suprascapular
Calving paralysis
Which nerve is affected here?
Suprascapular aka Sweeney
Consequences of suprascapular nerve paralysisProgressive neurological atrophy of supraspinatus & infraspinatus muscles
Lateral subluxation of shoulder when weight-bearing
Tx of suprascapular nerve dmgStall rest with light exercise until nerve regenerates or fibrosis occurs (stabilize joint)
Which nerve is affected here?
Radial nerve (dropped elbow; flexion of carpus, fetlock, & pastern; absent triceps reflex)
Most common cause of radial nerve dmgANX with animal in lateral recumbency
Can a cow with radial nerve damage stand?Can bear weight if leg in extension (can splint for this)
Which nerve is affected here?
Femoral (posterior delivery; difficulty rising, unable to fix stifle)
(Pic = norm day-old calf)
How does femoral nerve dmg occur?Hyperextension of the hip following a fall (adult) or forced traction in posterior presentation (calves)
Femoral nerve dmg: CSInability to extend/fix stifle
Patellar laxity, lateral displacement, absent patellar reflex
Flaccid quadriceps
Flexion of stifle, hock, fetlock, pastern when weight bearing
Which nerve is affected here?
How is the sciatic nerve most often damaged?Following forced extraction of oversized fetus
(Improper placement of IM injxns)
Sciatic nerve dmg: CSDropped & extended stifle, knuckling of fetlock, atrophy of hamstrings & muscles distal to stifle
How does peroneal nerve damage usually occur? why?(branch of sciatic) Recumbency/paresis because it is very superficial & courses over lateral condyle of fibula
Peroneal nerve dmg: CSHyperextension of hock, knuckling of fetlock & pastern, cutaneous analgesia of craniolateral limb distal to stifle
How does tibial nerve dmg usually occur?Improper injxn (caudal leg at lvl of stilfe)
SR: dog bite wounds
Tibial nerve dmg: CSFlexion of hock, pelvic asymmetry (affected side held lower), atrophy of gastrocnemius, analgesia of caudomedial leg
Which nerve is affected here?
Obturator (motor to adductor mm)
How does obturator nerve dmg occur? Spp differences?Cattle: intrapelvic trauma associated with dystocia
SR: nerve is more well-protected
Obturator nerve dmg: CSHopping gait, abduction of pelvic limbs (splay-legged)
Obturator nerve dmg: sequela? how to prevent it?Traumatic falls --> dislocating hip/stifle injuries. Patients should be hobbled
What is calving paralysis?Usually involves both the sciatic & obturator nerve components, evidenced by knuckling fetlock (peroneal) & inability to bear weight (sciatic & tibial) (if only obturator paralysis, cow can get up and down with good footing; sciatic prevents from rising)
Calving paralysis: TxAnti-inflam, analgesia
Supportice, correct e-lyte imbalances
Assist standing/walking; hobble to prevent splaying
Calving paralysis: preventionProper bull selection (esp w/ heifers)
Early intervention in dystocias, C-sections, fetotomies
**Ethics discussions with clients (4)Lead poisoning
Raw milk dairy w/ dz in calves or kids
Down & late-bred animal