Neuro - neuromuscular diseases Flashcards
What is the name for the connection between the nerve and the muscle?
Neuromuscular endplate
What is the acronym for assessing motor units?
RAT
Reflex arc decreased/absent
Atrophy of the muscle
Tone of muscles decreased
How do you test for muscle activity? What is abnormal?
Electrodiagnostic assessment - needle into leg, record muscle activity
Spontaneous electrical activity - myopathy/axonopathy
What can cause generalised acute loss of reflexes followed my muscle atrophy?
Polyradiculoneuritis
Botulism
Metabolic diseases
What can cause focal acute loss of reflexes followed my muscle atrophy?
Brachial plexus avulsion
What is polyradiculoneuritis?
Immune mediated disease attacking motor nerve axons of dogs
Causes acute flaccid tetraparesis
What is a differential for polyradiculoneuritis which is characterised by generalised neuromuscular neurolocalisation + megaoesophagus?
Myasthenia gravis
What is the treatment/prognosis for polyradiculoneuritis?
Physiotherapy
NO STEROIDS
Very good prognosis but takes 1-3 months
What is brachial plexus avulsion?
Focal neuromuscular disorder from trauma/scratch/wound disrupting reflexes of thoracic limbs
Often in cats
What is the main differential for brachial plexus avulsion?
Thromboembolism
What diseases can cause predominantly loss of muscle mass?
Polymyositis
Congenital myopathy
Nerve sheath tumour (focal)
What can cause polymyositis?
Immune mediated
Infectious
Paraneoplastic
What is a differential of a deteriorating lameness with marked pain and muscle atrophy?
Brachial plexus tumour
What is the treatment and prognosis of a brachial plexus tumour?
Surgery - tumour removal +/- amputation
Guarded prognosis - months to years
What diseases cause insidious onset fatigue with possible loss of reflexes and muscle mass?
Myasthenia gravis
Degenerative polyneuropathy
(CV and metabolic diseases)
What is myasthenia gravis?
Disease of the neuromuscular endplate
Immune system destroys acetyl choline receptors
Not enough acetyl choline to muscles, preventing them from initiating muscle contraction
How do you diagnose myasthenia gravis?
Regurgitation clinical sign - radiograph for megaoesophagus
Tensilon test - detect antibodies for the acetyl choline receptors
What is the treatment for myasthenia gravis?
Pyridostigmine - acetylcholinesterase inhibitor
Postural feeding for megaoesophagus
What is the prognosis for myasthenia gravis?
Guarded - aspiration pneumonia common complication
What is degenerative polyneuropathy? Where does it affect first?
Disease of peripheral nerves affecting larynx first then spreading to pelvic then thoracic limbs
Causes symmetrical non painful weakness and reluctance to walk, stirtor
How do you diagnose degenerative polyneuropathy?
Rule out metabolic differentials
Electrodiagnostics
Genetic testing
What is an early sign of degenerative polyneuropathy?
Laryngeal paralysis
Stirtor - difficulty breathing
What is the treatment/prognosis for degenerative polyneuropathy?
No cure - supportive treatment
Guarded prognosis
What are cranial neuropathies?
Conditions affecting the cranial nerves
What are some examples of acute cranial neuropathies?
Idiopathic facial nerve paralysis
Idiopathic peripheral vestibular syndrome
What are the signs of idiopathic facial nerve paralysis?
Peracute asymmetrical non painful
Facial asymmetry
Eye changes
Drooping face on one side
How do you test for idiopathic facial nerve paralysis?
Schirmer tear test
Corneal ulcer
What is the most common differential for peripheral vestibular disease?
Idiopathic peripheral vestibular syndrome
What is idiopathic peripheral vestibular syndrome?
Sudden onset vestibular signs - ataxia, circling, head tilt, nystagmus
Non painful
What is the prognosis of idiopathic peripheral vestibular syndrome?
Very good - dont euthanise!
Marked improvement over first 72 hours
What is a differential for idiopathic peripheral vestibular syndrome?
Otitis media/interna - check dogs ears
What are the clinical signs of a tail pull injury?
Flaccid tail
Flaccid anus
Urinary incontinence
Sciatic nerve deficits
What is the treatment/prognosis for tail pull injuries?
Bladder management - lifelong
Fair to guarded prognosis depending on severity - if no improvement after 6 weeks then unlikely to regain function
What is the localisation of a tail pull injury?
S1-S3
