Small Ani. Med- Neuro- Neuromuscular Disease 2

wilsbach's version from 2016-04-14 13:52

Botulism, tick paralysis, more lower mm neuro dzs...

Question Answer
pathophys of botulism?Ingestion of Clostridium botulinum’s preformed toxin (with C. tetani its usually an infection with the organism). and it ***Blocks ACh release (presynaptic)
clinical signs of botulism? Ascending diffuse lower motor neuron disease, Including some cranial nerve deficits (so all floppy and useless-- opposite of tetanus which is all spastic bc that toxin inhibits an inhibitory NT, whereas botulism is stopping the release of excitatory NT)
how do you dx botulism?Rule out other causes of diffuse lower motor neuron disease. Electrodiagnostics. There are no lesions on necropsy.
how do you tx botulism? prog?only supportive care-- might need ventilator. Prog: guarded.
what are the 3 types of ticks implied in tick paralysis? Dermacenter variabilis and D. andersoni, Ixodes holocyclus
explain the pathophys of tick paralysis, explain what situation allows tick paralysis to happenToxin is from the gravid female tick. AND Has to be on the dog for 5-9 days (really engorged). However, the exact MOA is unknown. They think it might interfere with ACh release, or interfere with propagation of an action potential
what are the CSs of tick paralysis?Rapidly ascending diffuse lower motor neuron signs: Hypo- to areflexia, difficulty breathing
dx of tick paralysisFind a tick (lol), Rule out other diffuse lower motor neuron disease (botulism, coonhound paralysis aka polyradiculoneuritis, maybe very bad MG.)
tx and px of tick paralysis?Tx: REMOVE THE TICK (yay simple), prog is EXCELLENT, if the tick can be found and wholly removed
coonhound paralysis is aka?Acute Idiopathic Polyradiculoneuritis
what does the word Polyradiculoneuritis mean?inflammation/dz of spinal ventral nerve roots (and some peripheral nerves i think).
pathophys of Acute Idiopathic Polyradiculoneuritis (coonhound paralysis)Probably autoimmune? Antigen: raccoon saliva? vaccine-related?
clinical signs of Acute Idiopathic Polyradiculoneuritis (coonhound paralysis)?Acutely ascending diffuse lower motor neuron signs... Including respiration (dyspnea) :( Sensorium unaffected (bc ventral nerve roots do motor, dorsals do sensory), SO Can wag tail and urinate/defecate normally
2 ways you can try to dx Acute Idiopathic Polyradiculoneuritis (coonhound paralysis)?Electrodiagnostics, Cerebrospinal fluid may have elevated protein
Treatment and prog of coonhound paralysis?Tx: LONG-TERM intensive supportive care and physical therapy. May require ventilatory support. However, good prog.
Chronic Relapsing Polyneuropathy: Who gets this?Older dogs and cats.
Chronic relapsing polyneuropathy: what is this a dz of? how does it present? how can you help it/prog?Ascending lower motor neuron paresis, and can have proprioceptive abnormalities. There is an Insidious (proceeding in a gradual, subtle way, but with harmful effects) onset. May respond to steroids. Tends to improve but can relapse-- guarde prog
Trigeminal Neuritis- how does this happen? What is this dz?idiopathic, it is inflammation of trigeminal nerve (V).
What are the CSs of trigeminal neuritis? treatment?Acute onset of the inability to close the mouth (dropped jaw), Spontaneous remission within 2-3 weeks :)! Treatment: Assist in feeding/drinking (might need a gruel), Physical therapy for the jaw (Open and close the mouth x 5 minutes, three times per day)
Infectious Neuropathies are caused by what 2 infectious agents? What problem do they cause, in WHO, and what are the CSs?Toxoplasma and neospora. You will see Polyradiculoneuritis, esp in puppies, which will present as Pelvic limb extension/joint contracture
Brachial plexus avulsion- where does it avulse? what are the CSs from this?Severe abduction of the thoracic limb will cause Avulsion at the level of the nerve roots, leading to CSs like: Lower motor neuron atrophy, reflexes+/- Horner’s syndrome (sympathetic nerve damage of ca poriton)
tx and px of brachial plexus avulsion?tx: Physical therapy, time (May require limb amputation). Prog varies.
tail avulsion in cats might lead to what problem?incontinence
Injection trauma- often occurs at the sciatic nerve. how does this look?can cause Needle puncture, hematoma, drug/product toxicity, or scarring... in younger animal will see less mm mass

Peripheral Nerve Injury, Metabolic Neuropathies, toxic neuropathies, Dysautonomia, Neoplastic Neuropathies

Question Answer
what is Neurapraxia? prog?bruising or stretching of nerve-- but nerve will be ok. There will be Transient lack of nerve function but Little or no structural damage to the nerve-- there is Good prognosis for return of function
what is Axonotmesis? prog?Damage to the axon but connective tissue support remains-- Axons can regrow along the basal lamina/connective tissue scaffold. Guarded to good prognosis for return to function
what is Neurotmesis? prog?Completely transected nerve :( No ability to regrow. Grave prognosis for return to function.
how can you differentiate Neurapraxia, Axonotmesis, and Neurotmesis?These all look the same (at first) clinically. It takes about one week for lower motor neuron atrophy (and associated electrodiagnostic abnormalities) to reveal itself (in class she said: so give them plenty of time-- a week to see how bad it is. 3-6mo to see how much they will recover. )
Who gets DM related metabolic neuropathy more cats or dogs?Cats
explain pathophys of diabetes related metabolic neuropathy?Pathophysiology unclear (several hypotheses): Microvascular disease vs. metabolic aberrations vs. immunologic attack of myelin
Clinical signs of DM related metabolic neuropathy?Paraparesis, Plantigrade stance, Lower motor neuron reflexes and atrophy
tx and px of DM related metabolic neuropathy? tx: tx the beetus. Px: Function may or may not return when good diabetes control is achieved
Hypothyroidism causes a metabolic neuropathy but there is Unknown pathophysiology. Association between hypothyroidism and polyneuropathy is suspected but is difficult to prove... however you can see what problems/dzs with this dZ?Laryngeal paralysis, Facial nerve paresis/paralysis, Peripheral vestibular syndrome, Megaesophagus, Lower motor neuron reflexes and paresis/paralysis
Delayed organophosphate toxicity: who gets this? What is the pathophys? CSs? dx and tx?Happens in CATS, due to Chronic exposure, unknown pathophysiology. You will see Paraparesis with decreased postural reactions (Lower motor neuron reflexes). Diagnosis based on signalment, history, and cholinesterase activity. TX= 2PAM (aka Pralidoxime (2-pyridine aldoxime methyl chloride,) )
What chemotherapy might cause a toxic neuropathy? how does it present and how to you tx?Vincristine! Not common tho. You will see Paraparesis with decreased postural reactions, Lower motor neuron reflexes. Resolves with drug withdrawal
What is the geographic distribution of Dysautonomia?Kansas, Missouri
what is the signalment like for cats and dogs with dysautonomia?CATS: younger. DOGS: Outdoor, rural/farm
clinical signs of dysautonomia? prog?Almost any parasympathetic or sympathetic dysfunction (all the things). Prog guarded to grave
2 drugs you can use to dx dysautonomia?(1) Pilocarpine (you will see miosis if given) (non-selective muscarinic receptor agonist) (2) Bethanechol (improved ability to urinate) ( parasympathomimetic choline carbamate that selectively stimulates muscarinic receptors without any effect on nicotinic receptors. )
Peripheral nerve sheath tumor tend to happen in what two locations?Trigeminal nerve (mandibular branch she said in class) and brachial plexus
what are clinical signs of peripheral nerve sheath tumor?Clinical signs reflect location of disease! Can see Lower motor neuron reflexes, atrophy. Often very painful if in brachial plexus. May extend into the brainstem or spinal canal (See associated signs of encephalopathy or myelopathy). Horner’s syndrome (brachial plexus location)
which tumor can cause a Paraneoplastic syndrome of polyneuropathy?Insulinoma- unknown pathophys (kinda opposite of the DM but still causes neuropathy. needless to say, sugar and insulin are important for the nervous system lol)
what are the most common differential diagnoses for Diffuse Lower Motor Neuron Disease? (6)(Myasthenia gravis—acute, fulminant), botulism. tick paralysis. ‘Coonhound’ paralysis. Snake envenomnation, Chronic organophosphate toxicity