MNP - polyneuropathy Flashcards
Which protein is encoded by SCN9A? Which disease?
Sodium channel, voltage-gated, type 9, alpha subunit
Hereditary sensory and autonomic neuropathy (HSAN) = Congenital insensitivity to pain (CIP) in mixed breed
Which stain allows identification of mitochondria?
Nicotinamide adenine dinucleotide reductase reaction
How can you diagnose hyperoxaluria in cats?
Deficiency in enzyme D-glycerate dehydrogenese -> oxalate crystals -> can identify L-glyceric acid and/or oxalate in urine
What is the causative gene and the pathological hallmark in demyelinating motor and sensory neuropathy in Miniature Schnauzer ?
SBF2/MTMR13
Tomacula (presence of focally folded myelin sheaths)
Name 2 chemotherapy agents associated with development of neuropathy.
Vincristin
Cisplatin
Which type of botulism toxin affect dogs, cats, horses, and cattle?
Dogs – C and D
Cats – D (one case)
Horses – A, B and C
Cattle – C and D
What is the only described cause of neonatal tetanus in puppies?
Omphalitis
3–5 day old American Bully puppies from the same litter
What is the difference between tetanus and tetany?
Tetanus is sustained (continuous) contraction of muscle(s).
Tetany is variable, intermittent contraction of muscle(s).
What are the diagnostic criteria of immune mediated polyneuropathy in cats?
Progressive muscle weakness with relative symmetry in PL or 4 limbs.
Young age (juvenile or young adult)
History of previous episodes that resolved without treatment
Decreased or absent tendon reflexes in weak limbs
Absence of sensory deficit
Cranial nerve involvement, especially bilateral facial weakness
EDX consistent with motor axonal PN
Nerve biopsy consistent with nodo-paranodopathy
What tick species are implied in tick-paralysis?What is the mechanism of the toxin? EDX findings? Treatment? Outcome?
Tick species:
Australia: Ixodes holocyclus, Ixodes cornuatus
USA: Dermacentor andersoni, Dermatocentor variabilis
Toxin: prevents presynaptic release of ACh at NMJ (presynaptic disorder) -> clinical syndrome characterized by ascending flaccid paralysis.
EDX: mild decreased CMAP amplitude, normal MNCV, F-wave latencies, and F-wave ratio
Treatment: tick removal, hyperimmune serum and supportive care until clinical signs resolve.
Outcome: possible complete recovery, but mortality rates of 2–5% due to respiratory failure.
Explain the pathophysiology of the clinical disease called tetanus and the routes of transmission.
Tetanus is caused by an exotoxin (tetanospasmin) produced by the Gram-positive, rod-shaped, obligate anaerobic bacterium,Clostridium tetani.
Clostridial spores are found everywhere in the environment and enter the body most frequently through wound contamination, but can also enter the body via contaminated surgery and dental infection. Under anaerobic conditions, the spores germinate, colonize the tissues, and begin producing exotoxin.
The exotoxin enters motor nerve axons at peripheral neuromuscular junctions and is retrogradely transported to the central nervous system where it crosses synaptic membranes into inhibitory interneurons. Within interneurons, tetanospasmin destroys a vesicular synaptic membrane protein (VAMP, or synaptobrevin), a SNARE protein integral in the fusion of neurotransmitter vesicles to the pre-synaptic membrane. This prevents exocytosis of the inhibitory neurotransmitters glycine and GABA in the synaptic cleft. This lack of inhibition in turn leads to excessive excitation of motor neurons causing sustained muscle contraction (ie, tetanus).
Name 3 mutations responsible for polyneuropathy in Leonberg and give corresponding age of onset and type of transmission.
LPN 1: ARHGEF10 – 2-4 years (before 6 years) – autosomal recessive
LPN 2: GJA9 – 1-10 years (usually more than 6 years) – autosomal dominant
LPPN: CNTNAP1 – laryngeal Paralysis associated with Polyneuropathy
Which antibodies are sensitive and specific for IMPN in dogs and cats?
Anti-GM2
Dog: Se 65% - Sp 90%
Cats: Se 71% - Sp 78%
Anti-GalNAc-GD1a
Dog: Se 62% - Sp 89%
Cats: Se 71% - Sp 71%
Give 4 lysosomal storage diseases with involvement of PNS.
Fucosidosis
Globoid cell leukodystrophy
Glycogenosis
Sphingomyelinosis (Niemann-Pick)
Which factor was associated with significantly higher mortality in cats with tick-paralysis in Australia?
- Cases with body temperature <35%
- Not being clipped vs being clipped
- Not receiving TAS
- All of the above
4
Give 3 dog breeds affected by motor neuron disease.
Brittany Spaniel (SMA [AD])
Rottweiler (polyneuropathy, ocular abnormalities and neuronal vacuolation, POANV)
Swedish Lapland (Lysosomal, glycogen storage disease, type II, Pompe)
Collie, Doberman Pinscher, English Pointer, German Shepherd, Giant Breed crosses, Griffon Briquet/vendéen, Saluki
Name the disease that induce a dysfunction of the cutaneous distribution of the sympathetic nerve and its clinical signs.
Name: complex regional pain syndrome
Clinical signs:
Hyperesthesia
Allodynia
Hyper/hypothermia
Hyper/hypohidrosis
Oedema
Give the mutations associated with motor neuron disease in cats. How is characterized the survival time?
LIX1 & LNPEP (AR)
Rapid early progression, then stabilisation, and prolonged survival time
Dysautonomia in dogs and cats is usually associated with Horner: true or false?
False
Only mydriasis is described with delayed PLR. Some cats and dogs can present third eyelid protrusion.
examples of flaccid paresis or paralysi
Hypermagnesemia, botulism, tick paralysis