Lit Neuromuscular, MSK Flashcards
(117 cards)
1
Q
- What was the incidence of persistent fontanelles (PF) in Chihuhahuas?
- What are the predilection sites for PFs?
- Was there an association between PFs and chiari-like malformation/ syringomyelia-related clinical signs?
- PFs were associated with which individual characteristics and CNS structural abnormalities (name 4)?
A
Kiviranta JVIM 2021 (Parts I & II)
1. 92% with >/=1 PF.
2. Dorsal (48%), lateral (14%), caudal (37%) cranial surfaces.
3. Chihuahuas with CM/SM-related clinical signs have more numerous & larger PFs.
4. Small size, SM, ventriculomegaly, craniocervical junction overcrowding.
2
Q
- Tumor type and/or grade of canine gliomas were strongly associated between clin path findings and survival. (T/F)
- Which MRI characteristics were found to be useful in:
a) refining diagnosis of tumor type & grade?
b) predicting shorter survival?
A
José-López JVIM 2021
1. False - no association identified.
2. a) Oligodendrogliomas associated with smooth margins & T1W hypointensity (vs astrocytomas & undefined gliomas), and more commonly in contact with ventricles (vs astrocytomas). Tumor spread to neighbouring brain structures was associated with high-grade glioma.
2. b) Irregular/poorly defined margins, T2W heterogeneous signal, drop metastases (seizures = lower risk factor)
3
Q
What is the diagnostic utility of arterial spin labelling (ASL) in dogs & cats undergoing brain MRI?
A
Hoffmann JVIM 2021
Non-invasive technique that allows quantification of cerebral blood flow (CBF), can be useful to characterise various brain diseases.
4
Q
What was the major adverse effect noted in dogs undergoing implantable vagus nerve stimulation (VNS) for treatment of epilepsy, and what is the mechanism behind this?
A
Harcourt-Brown JVIM 2021
Coughing which is generally well tolerated, esp if current is increased slowly & other stimulation parameters are adapted for effect.
Vagus nerve contains large efferent myelinated A fibers & small, unmyelinated C fibers –> fibre depolarisation causes adverse effects (dysphonia, dysphagia, cough, dyspnea, paresthesia, headache, pain)
5
Q
List the dog breeds affected by hereditary sensory and autonomic neuropathies (HSANs), and the associated genetic variants.
A
Gutierrez-Quintana JVIM 2021
3 variants identified to date.
1. Inversion in RETREG1 (reticulophagy regulator 1) - encodes Golgi protein. Border Collies & BC crosses.
2. Point variant in GDNF gene - encodes glial cell-derived neurotrophic
factor. Pointer, English Springer Spaniel & French Spaniel.
3. RETREG1 - family of mixed breed dogs (all homozygotes). CSx severe acral
mutilation & progressive HL gait abnormalities.
6
Q
In dogs with acquired MG, what was the:
a) clinical remission (CR) rate
b) immunological remission (IR) rate
c) factors negatively correlated with CR
d) factors positively correlated with CR
A
Forgash JVIM 2021
a) 31% (no CSx 4wks after stopping tx)
b) 59% (all IR dogs also achieved CR)
c) older dogs, regurgitation at presentation, high initial [AChR Ab]
d) Younger dogs, dogs with co-morbid endocrine dz
7
Q
- What is the causal gene mutation identified in Golden Retrievers with congenital myasthenia gravis?
- Gene mutations in other dog breeds & modes of inheritance?
Differences in clinical presentation between congenital vs acquired MG?
A
Tsai JVIM 2020
1. Point mutation in COLQ gene that predicts an AA substitution (G294R). COLQ encodes the collagenous tail of AChE (enzyme responsible for termination of skeletal muscle contraction by clearing ACh at the NMJ)
- Danish Pointers - missense mutation in the gene encoding choline acetyltransferase
Labs - non-synonymous mutation in COLQ gene (encoding the collagen-like tail of the asymmetric acetylcholinesterase)
JRTs - deletion & non-synonymous mutation in the CHRNE gene (encodes the epsilon subunit of the nicotinic ACh receptor)
Congenital MG also reported in Smooth fox terriers & Eng Springer Spaniels (mutations not yet described) - Congenital MG - megaO is not a common clinical feature. CSx usually begin at weaning with progressive muscle weakness that is exacerbated by exercise.
8
Q
In cats with acquired MG without a cranial mediastinal mass (CMM), what were the most consistent clinical abnormalities?
What was the clinical progression and long term prognosis of acquired MG w/o CMM in cats?
A
Mignan JVIM 2020
1) Skeletal muscle weakness. 2) Fatigability induced or exacerbated by the wheelbarrow exercise stress test.
Frequently achieve immune remission (within 6mths of diagnosis); can be spontaneous. Excellent long-term outcome - so impt to differentiate from cats with CMM.
9
Q
What is serum high-mobility group box 1 (HMGB1) an indicator of in dogs?
Rank the serum [HMGB1]s in the following groups of dogs (from highest to lowest) and approximate [ ].
- Epilepsy course <3mths
- Healthy dogs
- Epileptic dogs
- Epilepsy course >3mths
A
Mediator of neuroinflammation.
- Epilepsy course >3mths (0.87ng/mL)
- Epileptic dogs (0.41ng/mL)
- Epilepsy <3mths (0.26ng/mL)
- Healthy dogs (0.12ng/mL)
No sig diff between dogs with non-epileptic brain dz & healthy dogs. Potentially useful biomarker of epilepsy.
10
Q
What proportion of dogs
a) Developed post-encephalitic epilepsy (PEE) after MUO?
b) Developed drug-resistant epilepsy?
c) Clinical features (list 2) & d) risk factors (list 2) for PEE development after MUO in dogs?
A
Kaczmarska JVIM 2020
a) 23%
b) 21%
c) Clinical features - younger, significant shorter survival times
d) Risk factors - presence of acute symptomatic seizures (ASS; OR = 4.76) & MRI hippocampal lesions.
11
Q
What proportion of dogs had effective seizure control with midazolam CRI:
- Dogs with cluster seizures (CS)
- Dogs with status epilepticus (SE)
- Overall (includes above + structural/reactive/idiopathic epilepsy)
Duration taken to achieve seizure control with midazolam CRI?
What was the incidence & type of adverse effects observed?
A
Bray JVIM 2020
CS - 81%
SE - 67%
Overall - 77.4%
~25hrs
22.6% AE, all mild (sedation, V+ or D+, hyperexcitability, ataxia, polyphagia)
12
Q
Describe the following associated with seizures triggered by eating (STE) in dogs:
- Clinical feature
- Predominant seizure type
- Most common breed identified
- Associated with structural disease in which regions of the brain
A
Brocal JVIM 2020
- >50% of seizures related to eating
- Focal seizures becoming generalised
- Retrievers (4/10)
- Parietal, temporal, and frontal cortex (perisylvian region)
13
Q
Repetitive transcranial magnetic stimulation (rTMS) to treat dogs drug-resistant IE:
- Define technique?
- Effect on seizure frequency?
- Duration of effect?
A
Charalambous JVIM 2020
- Non-invasive neurostimulation technique. May have potential long-lasting neuromodulatory effects on the brain - disrupts networks related to cortical hyperexcitability.
- Significantly reduced Monthly seizure frequency (MSF) & monthly seizure day frequency (MSDF)
- Overall effect of rTMS lasted 4 months (proportion of MSF post-TMS to pre-TMS <1).
14
Q
- What was the causal gene & mode of inheritance identified in Mini Schnauzers with demyelinating polyneuropathy?
- Describe
a) Presenting signs
b) Age of disease onset & clinical presentation
c) Treatment strategies
d) Disease progression & prognosis
A
Mariné JVIM 2020
1. MTRM13/SBF2, autosomal recessive.
- a) Hallmark CSx - regurgitation + megaO & aphonic bark. +/- obvious neuromuscular weakness despite EMG evidence of appendicular DMP.
b) Age of onset = 3-18mths, clinical presentation = 4-96 mths
c) Preventive feeding measures & symptomatic tx to control aspiration pneumonia (meds, elevated feeding).
d) Disease tends to remain stable long-term - occ asp pneumonia (rarely cause of death). Overall good px with medical management.
15
Q
Novel motor polyneuropathy in Siberian cats:
- Probable mode of inheritance
- Presenting signs
- Prognosis
A
Crawford JVIM 2020
a) Autosomal recessive
b) CSx – progressive or waxing/waning neuromuscular weakness (100%), normal sensory function (100%), variably decreased withdrawal reflexes (75%).
c) Good overall. Episodes self-limiting (usually within 1-4wks), recurrence (1 or more episodes) common but full recovery typical.
16
Q
What is the prevalence of seizures in:
- Dogs & cats with idiopathic internal hydrocephalus
- Post-ventriculoperitoneal shunting for internal hydrocephalus?
A
Farke JVIM 2020
1.7%
None observed in study population (98 dogs, 23 cats)
17
Q
Canine mucopolysaccharidosis type I (MPS-I) - describe:
a) Pathogenesis
b) Causal gene
c) Clinical presentation
d) 1 drug which may be useful in managing this disease.
A
Faller JVIM 2020
a) Lysosomal storage disorder. Caused by α-L-iduronidase enzyme deficiency –> accumulation of undegraded dermatan and heparan sulfates in cells –> secondary multiorgan dysfunction.
b) IDUA gene
c) Variable; dysmorphic appearance, MSK, ocular and cardiac defects. Can survive to adulthood.
d) Pentosan polyphosphate - improved CSx until euthanasia at 4.5yrs.
18
Q
Prevalence of post-ictal MRI changes in dogs?
These changes were most commonly associated with:
- Which CNS regions?
- Which seizure types?
- Seizure frequency
- What timing of MRI wrt last seizure activity
A
Maeso JAVMA 2021
~12%
Locations - piriform lobe, hippocampus, temporal neocortex, cingulate gyrus.
Idiopathic > structural epilepsy (but can occur with both)
Cluster seizures or status epilepticus (vs self-limiting seizures)
Shorter time between MRI & last seizure
19
Q
Define myoclonus & its classifications. What gene mutation is this associated with in dogs?
A
Lowrie JVIM 2017 (Review)
Sudden brief, involuntary muscle jerk. Epileptic vs non-epileptic in origin.
CLCN1 (skeletal muscle voltage-gated chloride) mutation
20
Q
Non-epileptic myoclonic activity can occur with which infection in dogs? Pathogenesis? How does this present clinically?
A
Lowrie JVIM 2017 (Review)
Canine distemper virus.
Constant repetitive myoclonus occurs due to focal lesions causing pathological changes to the LMN of the spinal cord & cranial nerve nuclei - results in pacemaker - rhythmic muscle contractions.
Usually affects 1+ limb +/- facial muscle twitches;
21
Q
What signalment is typical for cats affected by feline audiogenic reflex seizures (FARS)?
Clinical manifestation?
Prognosis?
What drug is effective (or ineffective) in the treatment of FARS?
A
Lowrie JFMS 2017 & 2018
Older cats (median 15yo at onset).
Birmans overrepresented (31%).
Seizures mostly triggered by high-frequency sounds, up to 20% spontaneous.
Generally non-progressive, but owner-perceived declining QOL with seizures >2yrs (not jumping, HL weakness, weight loss, less responsive).
Levetiracetam effective (decreased myoclonic seizure frequency by
>50%), whereas phenobarbital had minimal effect.
22
Q
List some conditions associated with progressive myoclonic epilepsy (PME) in cats & dogs.
A
Lowrie JVIM 2017 (Review)
- Part of a degenerative encephalopathy.
a) Lafora disease (dogs) - usually occur in response to auditory & visual stimuli. Sudden muscular twitches ranging from jerky head mvts to generalized muscle fasciculations.
b) Neuronal ceroid lipofuscinosis (NCL) i.e. lysosomal storage disorder (dogs). - Unidentified aetiology (feline audiogenic reflex seizures)
23
Q
What is Niemann-Pick type C disease NPC) that has been described in a cat? Mode of inheritance & causal mutation? Clinical manifesations?
A
Mauler JVIM 2017
Autosomal recessive. Neurovisceral lysosomal storage disorder - results in defective intracellular transport of cholesterol.
Missense mutation in NPC1 gene.
Neuro signs - cerebellar & vestibular signs as early as 6wks old. Progressive ataxia impairing ambulation - typically euthanised by 6mths.
24
Q
What % of dogs/cats with supratentorial herniation had no direct clinical signs of herniation? What did the presence of a transtentorial line to the rostroventral aspect of the
cerebellum (TTX) on MRI indicate?
A
Lewis JVIM 2016
75%
More severe caudal transtentorial herniation, worst 24hr survival.
25
What is a minimally invasive method of detecting high ICP in dogs?
Sasaoka JVIM 2018
Transcranial doppler ultrasound. **Increased ratio of systolic to diastolic mean velocity of the basilar artery** was associated with MRI findings of increased ICP.
26
What was the agreement between stereotactic brain biopsy vs traditional surgical resection or necropsy to diagnose intracranial neoplasia in dogs?
Kani JVIM 2019
High agreement for **tumor type** (kappa = 0.95), of which 100% concordance for meningiomas.
But **grade** agreement for gliomas was only k = 0.47, where SBB underrepresented glioma grade.
SBB had 81% diagnostic accuracy, worst with smaller tumors & fewer samples obtained.
27
(2 papers)
Apart from chiari malformation/syringomyelia, what other structural difference can CKCS dogs have in their spinal cords? What clinical implications does this difference have?
Sparks JVIM 2019
Spinal cord in CKCS terminates more caudally at sacrum (vs L7 in controls). Dural sac also terminates more caudally (associated with subsequent T-L syringomyelia).
Sparks JVIM 2021
Found that painful CKCS without SM have decreased distance between the SC termination
& dural sac, suggesting a shorter filum terminale length (band of fibrovascular and neuronal tissue). More caudal SC termination is associated with development of lumbar SM.
28
(2 papers)
What were the most common signs reported by owners of CKCS with/without SM based on a questionnaire?
What are some signs seen more commonly in CKCS with large syrinxes, vs dogs with chiari-like malformation (CM) that may not have synrinxes or have smaller ones?
Sparks JVIM 2018
Most common CSx = crying out when lifted.
Owner-reported findings were not significantly associated with presence or severity of SM, or neuro exam findings. Owner-reported lateralization of signs was significantly associated with SM lateralization.
Rusbridge JVIM 2019
* Phantom scratching (ipsilateral), scoliosis leading to torticollis if dorsal horn of SC is involved (ipsilateral shoulder deviation + contralateral head tilt), sensory & motor signs (weakness & postural deficits) only seen in dogs with wide syrinxes 4mm+.
* Vocalisation, spinal pain & other signs of pain (reduced activity/ jumping ability, touch aversion, altered emotional state, sleep disturbance) could be seen in even dogs without syrinxes.
29
(2 papers)
In a longitudinal study, did craniocervical junction (CCJ) anomalies in CKCS predict future development of syringomyelia? Where there differences in medical vs surgical treatment in determining clinical progression?
In what other breed are SM & CCJ abnormalities overrepresented, and were there any distinct features from those recognized in CKCS?
Cerda-Gonzalez JVIM 2016
No, not in this cohort. Study also looked at atlantooccipital overlapping but concluded larger studies needed to assess impact.
32% of asymptomatic dogs developed CSx at re-evaluation within 71mths.
No.
Kiviranta JVIM 2017
Chihuahuas.
CM present in 100% & SM present in 38% of study population.
Similarly dogs w/o syrinxes developed CM/SM-related signs, likely due to CCJ abnormalities.
30
What is mechanical testing potentially useful for when evaluated in CKCS with/ without craniocervical pain?
Sparks JVIM 2018
Mechanical sensitivity was not associated with presence of syringomyelia in this study, but did related to the presence of pain & CSx in CKCS - so may be useful to assess sensory abnormalities.
31
(2 papers)
What are the most common complications post ventriculoperitoneal shunt placement in dogs and cats with internal hydrocephalus respectively? When were these complications most likely to occur?
Post VPS placement, what was the association between decreased ventricular volume & clinical status?
Gradner JVIM 2019
Dogs - shunt obstruction (10%), pain (5.5%), shunt infection (4.1%), disconnection (4.1%), excessive shunting (2.7%), kinking (1.6%).
Cats - shunt coiling (15%), kinking (7.7%), obstruction (7.7%).
Most common in 1st 6 months post-placement.
Schmidt JVIM 2019
The extent of decrease in ventricular volume & increase in brain parenchyma after VPS are associated with improvement in CSx (resolution of ataxia & obtundation).
32
When is ventriculoperitoneal shunting considered an effective palliative option in dogs?
Orlandi JVIM 2020
Dogs with obstructive (hypertensive) hydrocephalus caused by tumors located within the third ventricle. VP shunting of the most dilated lateral ventricule resulted in rapid resolution of intracranial hypertension, and excellent clinical improvement post-op. Some dogs required 2nd VPS in the contralateral lateral ventricle.
33
Nova Scotia Duck Tolling retrievers can get what sort of brain disease associated with rapid eye movement (REM) sleep behaviour?
Barker JVIM 2016
Degenerative encephalopathy, autosomal recessive. Gray matter degeneration (necrosis/malacia) affecting the caudate nuclei & brainstem/spinal cord axons.
CSx start between 2mths-5yrs & are progressive. Px guarded, minimally responsive to tx.
34
In what canine breed has neuronal vacuolation and spinocerebellar degeneration (NVSD) been identified as a hereditary condition? What is the causal gene mutation?
What similar condition has been identified and in what 2 breeds?
Mhlanga-Mutangadura JVIM 2016
Rottweilers.
Homozygotes for RAB3GAP1 allele (asymptomatic heterozygous carriers identified).
Ataxia & weakness most common CSx.
**Polyneuropathy with ocular abnormalities & neuronal vacuolation (POANV). **
* Black Russian Terriers. Mutations in RAB3GAP1 gene which codes for a protein involved in membrane trafficking. Present with juvenile onset laryngeal paralysis & polyneuropathy.
* Alaskan Huskies - SINE insertion in RAB3GAP1 gene.
*Disruption of membrane trafficking could lead to neuronal vacuolation seen in NVSD & other spongiform encephalopathies.*
35
In a UK dog population, what breed was strongly predisposed to vestibular disease? What was the clinical response rate & median time to see improvement?
What is the proposed clinical benefit of propentofylline in dogs with vestibular disease?
Maria Radulescu JVIM 2020
French Bulldogs, Bulldogs, King Charles Spaniels, CKCS, Springer Spaniels.
41.8% dogs improved after ~4 days.
Propentofylline may speed up the brain's ability to compensate after unilateral vestibular damage (tx course 1mth+)
36
What gene region was found to be associated with hereditary ataxia in Scottish terriers?
Urkasemsin JVIM 2017
CFA X
Mode of inheritance not yet identified.
37
What are the features of paroxysmal dyskinesia in Border terriers?
Stassen JVIM 2017
Dystonia, muscle fasciculations & falling over.
67% responded to AED, 100% response to hypoallergenic gluten-free diet when trialled.
Likely complex mode of inheritance, specific gene mutation not detected in this study.
38
(2 papers)
What is Lafora disease? What breeds can be affected? What are the CSx?
What brain metabolite deranagements were identified in a dog with Lafora disease using brain proton magnetic resonance spectroscopy?
Flegel JVIM 2021
Lysosomal storage disease. Lafora protein absent, leading to branched precipitous glycogen.
Beagles (also Basset Hounds, Wire-haired Dachs).
**NHLRC1 (Malin) gene mutation.**
Autosomal recessive.
CSx: Myoclonus, seizures, behavioural changes (*increased photosensitivity, staring into space, reduced stress resistance, increased noise sensitivity & separation anxiety*), mental decline.
- Also common: coordination deficits, impaired vision & hearing (develop later).
Usually a normal life span, onset of CSx in middle aged (8yo).
Alisauskaite JVIM 2020
Decreased amounts of N-acetyl-aspartate (NAA) & glutamate-glutamine complex; increased
total choline & phosphoethanolamine
39
What is the most common cause of unilateral MM atrophy in dogs?
What is the MST?
What was a negative prognostic indicator?
Milodowski JVIM 2019
Trigeminal NST in 47.6%. Other mass lesions accounted for 20.6%. Idiopathic 28% (no MRI lesions).
MST 5mths
Dogs with mass lesions more likely euthanised or had neuro deterioration.
40
xx
41
Name a dog breed to have a described juvenile degenerative polyneuropathy associated with laryngeal paralysis & megaO. What were the treatments administered & clinical response?
What hereditary adult onset neuropathy has been described in this breed?
Vandenberghe JVIM 2018
American staffies. Autosomal recessive.
Generalised sensory + motor nerve involvement.
Lar par common (71%; 10/14 dogs), megaesophagus (7%; 1/14 dogs).
Surgery for larpar improved QOL. Slowly progressive disease in most dogs; post-op lifespan was then similar to normal dogs apart from locomotor disturbances.
Adult onset: cerebellar degeneration secondary to ceroid lipofuscinosis.
42
What population variables (sex/weight/breed) were associated with risk of seizures in a UK prevalence study?
Erlen JVIM 2018
Males, BW 40kg+, Labradors & Pugs (Boxers, Basset Hounds, Border Terrier, Border Collies)
43
(2 papers)
What factors can predict in-hospital seizures for dogs presented for seizure evaluation?
What additional seizure-precipitating factors were identified in dogs with IE?
Kwiatkowska JVIM 2018
50% of dogs seized in this paper, within mean 7hrs. IE dogs had the highest seizure recurrence rate (53%).
Predictive factors:
- All dogs (IE + structural + reactive epilepsy): clusters/SE in the 72hrs before presentation & abnormal neurological exam.
- IE dogs: post-ictal prosencephalic signs also predictive
*Prosencephalic signs: mentation changes, visual deficits.*
Forsgård JVIM 2019
Prevalence of seizure-precipitating factors = 74% in this study.
Stressful situations, sleep deprivation, weather & hormonal factors.
In dogs with focal seizures, no. of precipitating factors was 1.9x higher vs dogs with generalized seizures.
44
What was the impact of of oral cannabidiol (CBD) in conjunction with AEDs on seizure control in a placebo controlled trial in dogs?
McGrath JAVMA 2019
CBD 2.5mg/kg PO BID x12wks.
Reduction in seizure frequency by 33% (plasma [CBD] correlated with reduction in seizure freq). But no difference in response vs control groups (defined as 50+% reduction in seizures) - possible that higher dose may benefit.
Tx dogs had increased ALKP activity.
45
What was the impact of a MCT-enriched diet supplementation on seizure control in dogs with idiopathic epilepsy?
Berk JVIM 2020
Included dogs with 3+ seizure in 3 months.
9% ME-based amt of MCT.
Significantly reduced seizure frequency & seizure-day frequency.
Variable improvements (2/28 seizure-free, 3/28 50+% reduction, 12/28 <50% reduction, 11/28 no change).
Study also noted MCT supp improved tolerability of AED (less ataxia). MCT oil & metabolites may affect phenobarbitone absorption & excretion rates due to common metabolism by cytochrome p450 enzymes >> sig lower serum [ ] though clinically did not manifest as more seizures.
46
What impact do AEDs have on activity levels & sleep scores in dogs with IE?
Barry JVIM 2021
IE dogs receiving AEDs have 18% lower baseline activity; greatest decrease with phenobarb + KBr combo (28%). No difference in sleep scores.
47
What were distinct clinical characteristics associated with focal epilepsy in a litter of Boerboel dogs?
Stassen JVIM 2019
Paroxysmal fear behaviours.
All dogs also had autonomic or motor signs.
Histo - moderate #s of single large vacuoles in the perikaryon of neurons throughout the brain (specifically deep cerebral cortex).
48
What structural brain changes may be seen on MRI in dogs with epilepsy? What sort of epilepsy may these be associated with?
Czerwik JVIM 2018
Unilateral reduced hippocampal volume (hippocampal atrophy (HA)).
35% dogs had EEG changes (epileptiform discharges (ED)) in the temporal leads - could reflect features of temporal lobe epilepsy.
88% dogs with ED in temporal leads had ED correlated with side of HA.
49
What are common triggers for reflex epilepsy in dogs?
Shell JAVMA 2017
Visits to vets & grooming facilities.
19% dogs had seizures at other times & sedatives were not effective
50
What is high-mobility group box 1?
What differences in serum HMGB1 levels were observed btween epileptic dogs vs dogs with non-epileptic brain disease & healthy controls?
Koo JVIM 2020
HMGB1 = ubiquitous nuclear protein related to inflammation. HMGB1 release from glial cells and neurons, activated
by inflammasome activation > may reduce seizure threshold via HMGB1-mediated IL-1β & neuronal TLR-4 activation.
Epileptic dogs had higher serum HMGB1 levels, esp dogs with epilepsy >3mths.
No sig diff between non-epileptic CNS disease & healthy dogs.
51
(2 papers)
What post-ictal biochemical change may be noted in epileptic cats?
What complication can occur following severe cluster seizures in cats?
Do any of these changes/complications require specific treatment?
Nilsson JFMS 2020
Post-ictal hyperammonemia (NH3 146-195upmol/L in this study)
No, self-limiting within 2hrs to 3 days.
Balducci JFMS 2017
Transient neurogenic urinary retention - resolved within 4 wks of cluster seizures. 1 cat needed phenoxybenzamine (non-selective alpha receptor blocker) to reduce IUS tone.
52
What aetiology was most common in cats with juvenile onset seizures (<12mo)?
Qahwash JAVMA 2018
Structural epilepsy (50%) most common - congenital malformations, FIP & head trauma.
IE & reactive seizures (25% each)
Median onset ~6mths.
No sig association between seizure aetiology & clinical features (age at onset, clusters, generalised vs focal)
53
What is the reported prevalence of recurrent seizure disorders (RSD) & epilepsy in cats presenting to primary care veterinary practices in the UK?
Any risk factors identified?
O'Neill JVIM 2020
Prevalence - 0.16% for RSD, 0.04% for epilepsy.
Risk factors:
- Aging - middle aged-older (3-6yo, 3.32x odds vs <3yo)
- Insured cats
54
JFMS review:
1. What % of cats with intracranial lymphoma are FeLV positive?
2. What is a major risk factor for ischemic CVA in cats?
3. What is the causal agent/pathogenesis of feline ischemic encephalopathy? Clinical outcome?
Hazenfratz JFMS 2018 review
1. 18%
2. Systemic hypertension (2' to renal disease or hyperT)
3. Aberrant migration of Cuterebra spp. larvae in the brain.
- Usually in young cats (<4yo) with outdoor access. Larvae migrate through the nares & sinus (URT signs) > through cribriform plate > migration into the CNS causes hemorrhage, necrosis & secondary vasospasm; areas perfused by the middle cerebral a. are infarcted causing acute forebrain signs.
- Few cats die; others significantly improve. Msy have permanent behavioural changes (esp aggression) & some require long term AED.
55
What structural brain change is associated with recurrent seizures in cats? Which cats are at higher risk?
Hazenfratz JFMS 2018 review
Kitz JVIM 2017 (Feline temporal lobe epilepsy review)
Hippocampal necrosis (6-30% of seizuring cats). Unknown if hippocampal lesions are cause or effect of seizures.
- Cats with focal onset seizures with secondary generalization that develop SE after a prolonged hx of recurrent seizures at highest risk.
- Cats with inflammatory or neoplastic infiltrates of hippocampi at high risk.
- Associated with severe progressive cluster seizures, which often have **orofacial involvement (head turning upwards, salivation, facial twitching, mastication, licking - ipsilateral to lesion.** Behavioural changes can develop between episodes.
- Prognosis open, some recover but often poor. Reports of cats entering full remission with AED, supportive care, steroids.
56
What dietary factors pose a risk for thiamine (B1) deficiency in cats? What other neuro signs apart from seizures can be observed in affected cats? Which region (gray or white matter) of the CNS is affected?
Hazenfratz JFMS 2018 review
- Diets preserved with sulphur oxide, inadequate supp, where thiamine is degraded by heating, diets with thiaminase.
- Impaired vision, mydriasis, ataxia, head/neck ventroflexion, vestibular signs, coma, possible death.
- Grey matter - MRI lesions correspond to sites of emorrhage & oedema
57
What type of seizures (and associated clinical sign) is observed in juvenile myoclonic epilepsy in Rhodesian Ridgebacks? Causal gene mutation & mode of inheritance? Any effective treatment?
WIelaender JVIM 2018
Absence seizures (staring episodes)
Onset 10wks old.
Autosomal recessive with complete penetrance.
Deletion in DIRAS1 gene (responsible for ACh release)
Levetiracetam tx results in >95% decrease in frequency of myoclonic seizures, and resolution of absence seizures.
58
What is a diagnostic modality for determining if unusual behavioural events are seizure activity in dogs?
James JVIM 2017
Electroencephalography (EEG).
Wireless video EEG method validated in this paper; able to include/exclude diagnosis of epilepsy in 72% dogs (on ictal/inter-ictal epileptiform discharges).
Less frequent events was associated with a lack of diagnosis.
59
What % of dog/cat patients had no/subtle signs of seizure activity that required EEG for detection?
Did the presence of electrographic seizures (ES) or status epileptics (ESE) influence survival?
What risk factors were identified for the development of ES/ESE?
Granum JAVMA 2019
81%.
Yes, increased mortality rate (48% ES, 50% ESE) vs patients w/o either (19%).
Risk factors - young age, overt seizures within 8hrs before EEG, hx clusters.
60
1. What seizure frequency is an indication to start AEDs in cats? What are 2 other conditions that are also indications?
2. What is a poor prognostic indicator for cats with IE?
Hazenfratz JFMS 2018 seizure review
1. >1 seizure every 12-16 weeks or increasing frequency. Seizures occurring post head trauma, structural epilepsy (suspected or confirmed)
2. Progression from cluster seizures to SE. 10-20% cats (vs 40% for other seizure aetiologies).
61
What AEDs are recommended to treat epilepsy in cats & what are their documented efficacies?
Hazenfratz JFMS 2018 seizure review
1. **Phenobarbitone** - efficacy 60-90%+.
**2. Levetiracetam** - 70% IE cats with 50%+ reduction in seizure frequency
3. Zonisamide - anecdotal efficacy
4. Gabapentin
5. Pregabalin
6. Diazepam
7. KBr - contraindicated (40% resp signs)
62
What rare complication of phenobarbitone therapy has been reported in dogs & cats that can mimic neoplasia?
What other blood dyscrasias have been reported in a cat receiving PB?
Have similar clinical signs been reported with another AED in a cat?
JSAP 2018 (cat) & Lampe JVIM 2017 (dog)
Pseudolymphoma. Marked generalised lymphadenomegaly, hepatosplenomegaly +/- pyexia - resolves rapidly after drug discontinuation.
Lyraki JFMS 2020
Pancytopenia reported in a cat, resolved within 10wks of stopping PB.
Collinet JAVMA 2017
Zonisamide - hypersensitivity syndrome in a cat. Marked generalized peripheral lymphadenopathy, hyperglobulinemia, cytopenias. Corresponded with ZNS serum concentration > recc therapeutic range.
63
(3 papers)
Levetiracetam in cats:
1. Has a transdermal formulation been shown to be absorbed in cats?
2. Can LEV be maintained at therapeutic levels in cats given SID?
1. Smith JVIM 2019
Yes, as a lipophilic liposomic cream vehicle (retains [ ] of 400mg/ml up to 5 weeks). Serum concentrations >= 5ug/ml. Given 60mg/kg TID.
2. Barnard JVIM 2018
Therapeutic levels in cats unknown. However, this study showed that extended release LEV at 500mg PO SID reached serum concentrations >5ug/ml (minimum recommended in humans) at 90min & maintained for 21hrs. A couple of cats had sedation & 1 had V+.
3. Barnes Heller JVIM 2018
Similar study to Barnard 2018, but evaluated multiple doses (x10d) of XR LEV. Similar findings to Barnard study. Well tolerated drug, concluded may be more feasible option vs TID dosing of intermediate release tabs.
64
(2 papers)
LEV in dogs:
1. Do phenobarbitone and/or zonisamide affect XR LEV pharmacokinetics in epileptic dogs?
2. Is rectally administered XR effective in preventing additional seizures in dogs with clusters or SE?
1. Muñana JVIM 2018
XR LEV monotherapy in itself has variable PK. PB - yes. ZNS - no. Study recc TDM while on XR LEV.
2. Cagnotti JVIM 2019
93% had good seizure control with single 40mg/kg dose rectally (+ standard AED tx of PB/DZ).
65
How does IN midazolam compare to the following for treatment of SE in dogs:
- IV midazolam (0.2mg/kg)
- Rectal diazepam
Charalambous JVIM 2019
Comparable (stopped in 76% - IN vs 61% - IV). Given the time to place an IV catheter, **IN was considered superior.** Both had similar incidence of sedation SE (88% IN, 79% IV).
Charalambous JVIM 2017
MDZ 0.2mg/kg via mucosal administration device (MAD) vs DZ 1mg/kg. **IN MDZ was superior**. Terminated SE in 70% dogs (cf 20% of DZ-treated dogs). All dogs had sedation & ataxia.
66
What breeds are at risk of SRMA and what was the reported relapse rate in a 2019 study?
Lau JVIM 2019
GR, BMD, Wirehaired Pointing Griffon, Boxer, Beagle. No breed diff in clinicial severity, dx findings, outcome.
48% relapse - correlated with increased CSF TNCC. Risk not associated with tx protocol (pred, CSA, myco, aza). In ~75% post cessation of prednisolone).
67
Are thoracolumbar and cisternal CSF samples equivalent?
Lampe JVIM 2019
No. Significant differences in CSF TNCC between cervical & thoracolumbar lesions (but not diff for brain lesions).
In dogs with T-L lesions, cisternal tap may miss diagnosis.
68
What is the significance of increased lactate on CSF? Did this predict survival in dogs with inflammatory CNS disease?
Mariani JVIM 2019
Weak positive correlations with CSF TNCC & protein.
No correlation with survival.
69
What neuronal cell surface autoantibody was identified in a small % of dogs with MUO? What type of receptor is it?
Stafford JVIM 2019
Anti-N-methyl-D-aspartate receptor 1 (NMDAR1) antibodies.
Glutamate ion-gated receptor.
70
List microRNAs that were upregulated (3) vs downregulated (1) each) in the CSF of dogs with osseous-associated cervical spondyomyelopathy.
Vansteenkiste JVIM 2019
Increased - miR-299-5p, miR-765, miR-494 (1.5x incr)
Decreased - miR-612 (1.2x lower)
71
What evidence is there to suggest MUO is an immune-mediated disease in dogs?
Hoon-Hanks JVIM 2018
Metagenomic study on FF CSF & brain samples.
No link to infectious agent (in this time period, -ve Bartonella paper and broader search for infectious organisms).
Another paper found some dogs positive for anti-NMDAR-1 (N-methyl-D-aspartate receptor 1) antibodies (neuronal surface protein) - similar to people.
72
What 2 biochemical parameters may be useful to differentiate between neosporal vs non-infectious meningoencephalomyelitis in dogs?
Jones JVIM 2021
High serum CK (1334U/L) & AST (124U/L) increases suspicion for neosporal ME.
- CK cutoff of 485 U/L had 95% Sn & 96% Sp, NPV >99%.
- AST 57 U/L had 94% Sn & 85% Sp, NPV 99%.
Study dogs also tested for toxo but none diagnosed.
73
(2 papers)
What is gangliosidosis a disease of? What is the pathogenesis and a breed affected?
What are the histopathological changes associated with progressive disease?
Wang JVIM 2018
Kolicheski JVIM 2017
Fatal neurodegenerative lysosomal storage disease, accumulation of ganglioside lipids in lysosomes. 2 forms:
- GM1 = Tay Sachs disease. Deficiency of **beta-galactosidase**.
>> Cerebellar dysfunction. Onset 5-6mths, usually death by 14-15mths. NB: 1% Shiba Inu are asymptomatic carriers.
- GM2 = Sandhoff's disease. Deficiency of **hexosaminidase-A (HEXA), b-hexosaminidase (HEXB) or GM2 activator protein (GM2A) **required for HEXA activity.
>> Similar CSX & progression as GM1.
Shiba Inu get both types (GLB1 frameshift mutation causes GM1. Homozygous 3bp deletion in HEXB gene causes GM2) - case report.
Ito JVIM 2018
2 yr FU in 1 dog with Sandoff's disease. Histo - severe myelin loss in cerebral & cerebellar white matter, dstruction of most cerebral & cerebellar neurons.
74
What clinical & CT findings are associated with neurological signs due to thoracic hemivertebrae in Frenchies, Pugs & Eng Bulldogs?
De Decker JVIM 2019
Pug breed (OR 10.8)
More severe kyphosis (OR 1.1 per grade increase)
Fewer observed hemivertebrae
Ventrolateral hypoplasia hemivertebra subtype (OR 4.0)
Cobb angle of 34.5deg (measures severity of dorsal curvature using commercial plug-in device) had highest Sn/Sp to differentate clinically affected dogs.
75
What was the link found between Campylobacter & acute polyradiculoneuritis (APN) in dogs? Campylobacteris spp implicated?
Most commonly affected nerve in APN?
Martinez-Anton JVIM 2018
APN dogs were 9.4x more likely to be campylobacter positive on faecal testing. Increased risk of being fed raw chicken (96%).
Most common spp. was C. upsaliensis
Most commonly affected nerve = vagal n. > dysphonia
76
What was the disease-specific survival for intracranial trigeminal PNST in dogs treated with stereotactic radiation?
Hansen JVIM 2016
745 days.
No acute adverse effects recorded.
Unable to confirm late RT effects vs tumor progression on histo due to PM in few cases.
77
How did a novel moderately hypofractionated RT protocol compare to the conventional (strongly hypofractionated) protocol in the treatment of dogs with primary intracranial tumors?
Schwarz JVIM 2018
Novel protocol = 10 × 4 Gy (conventional = 20x 2.5Gy)
Favourable PFI (663d) & OST (637d) - no sig diff between 2 protocols. Overall safe & efficient protocol.
78
What is the incident & risk factors for adverse effects occurring after stereotactic brain biopsy in dogs with primary intracranial neoplasia?
Shinn JVIM 2020
27% AE, most resolve within 1 wk. 88% dogs had hemorrhage post bx.
Lower platelet counts (recc >/=185K/mm3 for biopsy), T2W-heterogenous tumors. Presence of gradient echo signal voids present on baseline > higher risk of hemorrhage.
79
What CT/MRI parameters are used to assess therapeutic response to SRT or stereotactic radiosurgery in dogs with primary intracranial tumors?
What is the survival outcome in treated dogs?
Zwingenberger JVIM 2016
Tumor volume, blood flow & blood volume. Significant reductions in parameters at 3 & 6mth rechecks.
MST 324d. Treated dogs surviving >1yr more likely to die from other causes.
80
What gene mutation is associated with neuronal ceroid lipofuscinosis in Border Collies and Australian Cattle dogs? What are the clinical features?
What gene mutation was reported in a Cane Corso diagnosed with NCL?
Kolicheski JVIM 2016
CLN5 (homozygous nonsense mutation).
Accumulations of autofluorescent storage material within cerebellar, cerebral cortical, retinal, (cardiac muscle (1 dog). Degenerative disorder; seizures, blindness, multifocal CNS signs (cerebellar, forebrain)
Kolicheski JVIM 2017
Homozygous CLN1 splice donor mutation.
81
What is a meningocele (MC) vs meningoencephalocele (MEC)?
What intracranial anomaly accompanies these?
What are the clinical features of dogs with MC & MEC?
Treatment options available & response?
Lazzerini JVIM 2017
MEC = herniation of cerebral tissue & meninges through a
defect in the cranium. MC = herniation of meninges alone.
Concurrent porencephaly in 100% dogs (CSF-filled cavity/cyst in the brain).
Young dogs (median 6.5mths). Seizures & behavioural abnormalities.
Intranasal MEC > common cf parietal MC.
MRI identified meningeal enhancement of protruded tissue in 77% cases. CSF analysis WNL in 55% dogs; mild abnormalities in 45%.
17/22 dogs were medically managed with AEDs. No dogs had sx. Dogs with intranasal MEC & mild neuro signs had a fair px with medical tx.
82
In dogs with spinal epidural empyema, which cases were amenable to medical management rather than sx?
Monteiro JAVMA 2016
5 dogs in this study. Causes - diskospondylitis, prostatitis, dermatitis, paraspinal infection 2' to penetrating injury, UTI, pyothorax. Bacterial isolated from 3 dogs (E coli, pasteurella, corynebacterium). All dogs had improvement within 2 wks of abx, no sx, good long term outcome.
Decisions for medical tx: minimal-no SC compression, mild neuro deficits, severe lesion extension.
83
What is the causal gene mutation for sensory neuropathy in Border Collies? Brief pathogenesis?
Amengual-Batle JVIM 2018
FAM134B (homozygous). Gene encodes a cis-Golgi protein found in sensory and autonomic neurons. Patho incompletely but defect induces apoptosis in neurons of the dorsal root ganglia.
84
In a retrospective study of canine renal biopsies, which 1 category of glomerular disease had the most severe protein loss? And which morphological diagnosis was associated with most severe proteinuria?
Aresu JVIM 2017
**Immune-complex-mediated GN (ICGN) **had lower serum alb & higher UPC (vs non-ICGN & renal lesions not otherwise specified/RL-NOS groups).
Morphological dx - sig lower serum albumin in **membranoproliferative (MPGN) ** (also amyloidosis, membranous (MGN), mixed glomerulonephritis (MixGN).)
85
(2 papers)
What % of dogs with TL IVD herniation developed ascending/descending myelomalacia (ADMM)? What are the risk factors for ADMM?
What is the typical timeframe for onset of ADMM?
Balducci JVIM 2017
2%.
Risk factors - age (<5.8yrs), neuro status years), neurological status at admission (grade 5 14.5%, grade 4 2.7%), site of IVD herniation (L5-L6), duration of CSx before becoming non-ambulatory (<24hrs), intramedullary T2-weighted (T2W) hyperintensity on MRI, T2 length ratio >4.57.
Castel JVIM 2017
Most developed ADMM within 2d of presentation, euthanised within another 3d. Delayed onset possible (up to 5d, euthanasia as long as 2 weeks after).
Risk factor: location - mid-caudal lumbar IVDD - similar to above.
86
What biomarker may predict outcome in dogs with IVDE-associated TL paralysis with no pain perception? What is the Sn/Sp?
Olby JVIM 2019
GFAP (glial fibrillary acidic protein) = type of CNS-specific protein released from dying neurons & glial cells.
Incr D1-3, then decr to undetectable by D14 & 28. GFAP [ ] after onset of non-ambulation had 76-89% accuracy depending on time of sampling (highest accuracy at D3).
87
Did polyethylene glycol (PEG) or methylpred Na succinate (MPSS) confer a clinical benefit in dogs with acute severe TL-IVDE? What is the rationale for PEG?
Olby JVIM 2016
No for both.
PEG has abiity to fuse membranes & improved outcome
in experimental canine models of spinal cord injury, comparable outcome with sx alone.
88
Did polyethylene glycol (PEG) or methylpred Na succinate (MPSS) confer a clinical benefit in dogs with acute severe TL-IVDE? What is the rationale for PEG?
Olby JVIM 2016
No for both.
PEG has abiity to fuse membranes & improved outcome
in experimental canine models of spinal cord injury, comparable outcome with sx alone.
89
Apart from pulmonary fibrosis in WHWTs, what neuromuscular disease can the 6-minute walk test be used for in dogs? What is the causal gene mutation for this disease & the outcome of the 6MWT?
Cerda-Gonzalez JVIM 2016
Centronuclear myopathy (CNM) in Labs.
PTPLA (protein tyrosine phosphatase-like A) gene mutation.
6MWT (distance walked) was helpful to differentiate between the ambulatory capacity (influenced by degree of paresis) in CNM-affected vs normal dogs/carriers.
90
What is osteochondromatosis? Which breed and hat gene mutation are associated with this disease?
Friedenberg JVIM 2018
Rare skeletal developmental disorder characterized by the appearance of cartilage capped boney outgrowths (exostoses) that continue to develop and grow until skeletal maturity. CSx - compression of nerves, spinal cord or other tissues --> nerve pain, paralysis, <5% malignant transformation.
American staffies. EXT2 (exostosin 2).
91
What % of paraplegic dogs with TL lesions develop spinal walking & median duration? What patient factors are positively associated development of SW?
Gallucci JVIM 2017
59% in this study, median time 75 days.
Younger age, lightweight (
92
What gene mutation is associated with deafness & vestibular function in Dobermans? What is the prevalence of this mutation in the study population?
Guevar JVIM 2018
Protein tyrosine phosphatase, receptor type Q (PTPRQ) mutation - homozygous
1.5% prevalence.
93
How do saccadic oscillations differ from other forms of nystagmus?
What CNS disease is typically associated with these oscillations?
Ives JVIM 2018
Fast saccadic eye movement,r ather than initial slow drift then fast corrective phase.
Cerebellar disease (central vestibular) observed in all dogs in this study.
94
What are clinical manifestations of corpus callosum abnormalities in dogs? What CNS lesions are characteristic & what imaging method may allow better visualisation of these lesions?
Johnson JVIM 2019
Adipsia/hypodipsia > life-threatening hyperNa + long term neuro signs.
White matter malformation - Probst bundles (fibres cross at level of splenum forming logituindal callosal fasciculi). Diffusion tractography - outlines exact location of major WM pathways in the brain.
95
What signalment & clinical features are associated with putative cerebral microbleeds (PMBs) on MRI in dogs? Are PMBs prognostic for survival?
Kerwin JVIM 2017
Older, smaller dogs.
Vestibular signs, cortical atrophy, proteinuria (OR 3) more common.
Yes, PMB dogs had shorter survival.
96
Name 2 gene mutations associated with congenital muscular dystrophies in dogs.
What was a new gene mutation identified based on a JVIM 2021 case report?
Shelton JVIM 2021
COL6A3 in Labrador retrievers & COL6A1 in Landseer dogs.
New gene mutation in LAMA2 (encodes subunit of the laminin-2 complex. Laminins = large glycoproteins that are structural components
of BMs in many tissues).
97
What is the role of matrix metalloproteinases (MMPs) in tumors? What were MMPs & TIMPs (MMP inhibitors) expression levels in dogs with papillary meningomas? Did these change with tumor grade?
Mandara JVIM 2017
MMPs are involved in tissue remodelling by proteolytic activity > degradation of ECM followed by infiltration of tissue is a triggering event for tumor progression/recurrence.
Higher MMP-2 & higher MMP-2/TIMP-2 ratio in papillary meningiomas > may contribute to aggressive biological behaviour of tumor. TIMP-1 expression higher in grades I & III.
98
What was the incidence & risk factors identified for development of urinary or faecal incontinence in dogs with T-L ANNPE (acute noncompressive nucleus pulposus
extrusion)?
Mari JVIM 2019
UI 9.1%, FI 23.5%
FI - paraplegic dogs, no NSAID tx, spinal shock on presentation
UI - intramedullary hyperintensity >40% of SC cross-sectional area on T2W MRI (larger lesions)
99
What breeds & clinical features are overrepresented in kittens with congenital sensorineural deafness in the UK, and what %?
Mari JVIM 2019
Solid white kittens, 30% (16% uni vs 14% bilateral). 1 or 2 blue irises (vs none) 3.2x more likely to have CSD.
Breeds - Norwegian Forest, Maine Coon, Turkish Vankedisi.
100
What optic nerve changes can be observed in dogs with systemic hypertension presenting for acute blindness?
Mari JVIM 2018
Ischemic optic neuropathy (pre-chiasmic blindness) - vision did not recover even with tx in this case report.
101
Following IVD extrusion in dogs, immunoreactivity to what marker over spinal cord segments may play a role in development of ascending/descending myelomalacia? Which cells had highest expression levels of this marker?
Mayer JVIM 2016
Endothelin-1 (vasoactive molecule)
Astrocytes of white matter = macrophages > neurons >>> endothelial cells. Not neutrophils.
102
What endocrinopathy may be associated with narcoplexy-cataplexy in dogs? Causal gene mutation for familial narcoplexy in dogs?
Schmid JVIM 2017
HyperA - in this case report clinical signs developed after SRT for pituitary macrotumor.
Hypocretin receptor 2 gene mutation >
deficiency in hypocretin ligand (hypocretin/orexin in CSF promotes wakefulness & muscle tone)
103
Were there significant prognostic differences for regaining urinary continence and ambulation in dogs with L4-S3 vs T3-L3 SC injury?
Shaw JVIM 2017
Dogs with L4-S3 SCI have poorer short-term px vs T3-L3 SCI.
Neg px factors (L4-S3) - loss of conscious pain perception (CPP), **non-compressive lesions** combined with **LMN** incontinence.
Excellent px: small-breed or chondrodystrophic dogs with retained CPP, **compressive lesions** & **UMN** incontinence.
104
What is the utility of transcranial magnetic motor evoked potentials (TMMEPs) in paraplegic dogs post decompressive surgery?
Siedenburg JVIM 2018
TMMEPs reflect motor function recovery (ambulatory status) - significantly increased amplitudes & decreased latencies at 2 follow ups (within 2 days of regaining motor function & 3 mths later)
105
What patient factor may lead to erroneous measurements when using a microsensor transducer to monitor ICP in dogs?
Sturges JVIM 2019
Conscious healthy dogs have transient ICP fluctuations. Head position can cause largre variations in ICP readings.
106
What drugs can be associated with myasthenia gravis in cats/dogs?
Mignan JVIM 2020 MG review
Thiourelyene drugs (e.g. methimazole)
107
How many % of MG dogs are seronegative on ACh receptor autoantibody testing?
Causes for seronegativity?
Mignan JVIM 2020 MG review
- Congenital MG
- Early disease - not yet seroconverted (retest 1-2 months later)
- Prior immunosuppressive tx
- Most of autoAb already bound in skeletal muscle (not in circulation)
- AutoAb directed against toxin binding site
- AutoAb directed against other post-synaptic NMJ components (rare)
- Assay related (damage to the antigenic epitopes during the process of solubilization thereby preventing recognition of AChR autoAb)
108
What are the 3 subgroups of congenital MG in dogs & cats? For each subgroup, list:
a) Defect
b) Gene mutation involved
c) Breeds affected
d) Diagnostic test results (AChR antibody, post-synaptic [AChR], skeletal/nerve bx)
e) Tx options
Mignan JVIM 2020 MG review
*All autosomal recessive*
1. Presynaptic - defective ACh synthesis. Old Danish Pointing dog. Exon 6 of CHAT (choline acetyltransferase) gene. AChR Ab neg, post-synaptic [AchR] WNL. Tx - AChE-Is worsen CSx, guanidine may help.
2. Synaptic - AChE deficiency. GRs (exon 13), Labs (exon 14). Sphynx & Devon Rex (exon 15). COLQ mutation (normally anchors AChE to NMJ). AChR Ab neg, post-synaptic [AchR] WNL. Nerve bx WNL. Skeleta m bx dystrophic changes. Tx B2-R agonist (albuterol) may help stabilize NMJ. AChE-I may worsen CSx.
3. Post-synaptic - ACh-R defect. JRT (exon 7), Heideterrier (exon 31). CHRNE gene (ε subunit of AChR). AChR Ab neg, **post-synaptic [AchR] markedly decreased**. Tx B2-R agonists & AChE-I.
109
Based on a case-control study, which of the following were risk factors for GME in dogs?
- Season
- Time of last vaccination
- Age
- BW
Heller JAVMA 2019
None
110
Were there differences in diagnostic yield between CSF collection both cisternal & lumbar sites vs collection from 1 site in dogs with SRMA?
Carletti JAVMA 2019
Yes, higher chance of detecting high TNCC with 2 site collection.
111
What are the risk factors for development of discospondylitis in dogs post IVDD surgery?
Canal JAVMA 2016
BW >20kg (uni-variate: GSD OR 9.8, >8.8yo, disk protrusions)
112
What MRI & MR angiography findings may help differentiate between meningiomas & intracranial histiocytic sarcomas in dogs?
Ishikawa JAVMA 2016
MRI T2W, FLAIR: meningiomas hyperintense, IHs iso or hypointense.
Peri-tumor vessels displaced in 8/9 meningiomas, none for IHs.
113
What 2 factors increase the odds of major complications or death in dogs within 30 days of cytoreductive sx for intracranial masses? What complications were noted?
Kohler JAVMA 2018
Pre-op abnormal neuro exam, suboccipital approach. Complications - seizures 11%, worsening neuro status 3.8%, aspiration pneumonia 3.8%.
114
What is the diagnostic utility of serum pNF-H in dogs with acute severe TL Type IVDH?
Murthy JVIM 2021 & Olby 2022 ACVIM IVD consensus
No difference in serum pNfH concentrations at presentation. Also no correlation with recovery in deep pain negative dogs
But dogs that develop PMM have significant pNF-H elevation (31.39+ng/mL) at 24hrs post-op; 100% Sp & 83% Sn.
115
What histopathologic abnormalities were observed in a litter of Norwegian Buhunds with hereditary cerebellar ataxia?
Mari JAVMA 2018
Changes reflect Purkinje cell dysfunction. Markedly reduced expression of markers of Purkinje cell differentiation (calbindin D28K & inositol triphosphate receptor 1), mild neuronal degeneration.
Autosomal recessive.
116
Was pre-op tumor volume (determined by MRI) predictive of post-surgical outcome & survival in dogs with primary intracranial gliomas?
MacLellan JAVMA 2018
Not in this study. But tumor grade was predictive of outcome (need invasive bx).
117
What % of dogs with congenital hydrocephalus had neurological improvement with medical management (oral pred) alone? How did this compare to dogs that had VP shunt placement?
Gillespie JAVMA 2019
50% improved with med management.
Sx - 54% improved, 4% stable, 41% deteriorated, 15% post-op complications.
(Note large difference in study group size)
