Neurological: weakness and Exercise intollerance

Question 1

Classifications (3)

Answer 1

neuropathy: disease that affects the neurone or scwann cells
- persistetn weakness
- loss of cutaneous sensation
- often loss of bark/megaoesophagous
- +/- CN deficits

junctionopathy: disease that affects the neuromuscular junction
myopathy: disease that afffects the muscle

Question 2

Persistent deficit diseases

Answer 2

diabetic neuropathy
neospora caninum
toxoplasma gondii
traumatic
horners
botulism and tick paralysis

Question 3

diabetic neuropathy

• what (2)
• prognosis (2)

Answer 3

• poorly controlled diabetes causes distal axonal degenration
• longest peripheral nerves are affected first –> pelvic limb plantigrade stance

guarded prognosis:
restoring normoglycaemia prevents progression

Question 4

malignant peripheral nerve sheath tumours

where
CS
Dx
Tx

Answer 4

most common in brachial and lumbar plexua

• brachial: palpable mass on axilla/pain on palpation?
• lumbar plexus: sometimes palpable mass on rectal?

CS: muscle atrophy

Dx: electromyography confirms muscle denervation, MRI

Tx: amputation of distal tumour, poor prognosis (invasive and tend to come back)

Question 5

Neospora Caninum

• what
• transmission
• CS
• Dx
• Tx

Answer 5

Protozoan parasite
transplacental transmission to puppies

CS:

• 3-8 weeks old
• affects pelvic limbs
• progressive LMN signs
• quadriceps contracture

Dx:

• Serology, PCR
• CSF
• Biposy (neuritis and myositis)

Tx:

• clindamycin
• trimethoprim-suldadiazine

Question 6

Toxoplasma Gondii

• what
• transmission
• CS
• Tx

Answer 6

protozoan parasite
ingestion of bradyzoites or transplacental

CS: multsystemic _ respiritory, muscle, periveral nerves, CNS

Tx: clindamycin or trimethoprim sulphonamide

relapse is likely

Question 7

Traumatic neuropathies

Answer 7

Neuropraxia: interruption of nerve conduction without physical disruption of the axon

axonotmesis: physical interruption of the acon but the endoneurium and the schwann cells remain in tact: regrowth at 1-4mm/day
neurotmesis: complete resection of the nerve: unlikely recovery

Question 8

Botulism (3)

Answer 8

toxin causes flaccid paralysis by preventing synaptic release of acetylcholine

supportive treatment

recovery in 3 weeks

Question 9

Tick Paralysis (2)

Answer 9

toxin in saliva prevents release of acetylcholine

signs resovle after 1-3 days of tick removal

Question 10

Myasthenia gravis

Types (2)
   causes
Dx (3)
Tx (3)
Prognosis

Answer 10

congenital form: rare: congenital problem with Ach receptors
progressive
Dx: CS, response to treatment

acquired: autoimmune –> antibodies against nicotinic receptors of neuromuscular junction
some times paraneoplastic (secondary due to thyoma)

focal form (affects one muscular group only) of generalised form (exercise intolerance, collapsing episodes)

Dx:

• Ach recetor antibodies
• tensilon tets: edrophonium
• thoracic radiographs (megaoesophagous, aspiration pneumonia, mediastinal masses)

Tx:

• aticholinesterase drugs : piridostigmine
• immunosuppressive therapy : prednisilone
• management of other problems

Prognosis: 48% die in first few days, spontaneous remission in 885 of cases that survive

Question 11

Polymyositis

• causes (3)
• Dx (2)
• Tx (2)

Answer 11

causes

• autoimmune: lots of inflammatory cells on biopsy
• infectious (toxoplasma, neospora, tick borne)
• paraneoplastic

Dx:

• muscle enzymes: CK, ALT & AST
• muscle biopsy

Tx: tapering dose of immunosuppresive steroids for the autoimmune form
-specific ABs for infectious form