Neuromuscular Syndromes

Question 1

Hallmarks of LMN Disease

Answer 1

Weakness
Exercise intolerance
\+/- CN deficits
Voice change
Muscle atrophy
\+/- autonomic signs

Question 2

5 Ddx for acute LMN flaccid paresis

Answer 2

1. Botulism
2. Coral Snake envenomation
3. Myasthenia gravis
4. Tick paralysis
5. Polyradiculoneuritis

Question 3

Polyradiculoneuritis

Answer 3

Acute, ascending flaccid paralysis

MOTOR not sensory

Required supportive care, possibly ventilation

Albuminocytologic dissociation on CSF

Abnormal F wave

Question 4

F wave

Answer 4

Evaluates the nerve root using orthodromic and antidromic stimuli

Question 5

What breed is predisposed to an inherited polyneuropathy?

Answer 5

Leonberger

Question 6

Types of endocrine neuropathies

Answer 6

Paraneoplastic (insulinoma)

Hypothyroidism

Diabetic neuropathy (feline, plantagrade posture)

Question 7

Tick Paralysis

Answer 7

Pre-synapthic neuromuscular blockade*

Dermacentor and amblyomma most common

Dogs flaccid 5-9 days after tick attaches

Frontline

Question 8

Tetanus

Answer 8

Inhibits glycine/GABA release at spinal cord

Risus sardonicus, saw horse stance, elevated nictitans, exacerbated by external stimuli

Antitoxin: neutralizes circulating toxin

Antibiotics (PenG, tetracycyline, metro)

Sedatives, supportive care

Question 9

Botulism

Answer 9

Block presynaptic Ach release from nerve terminal

Progressive, symmetric paresis, autonomic signs

Improvement over 1-3 weeks

Question 10

Congenital Myasthenia Gravis

Answer 10

Jack and Parsons Russel Terriers

Signs from birth, generalized weakness

Insufficient RECEPTORS

Negative titers

Question 11

Acquired Myasthenia Gravis

Answer 11

Focal (1/3) or Generalized (2/3), Fulminant (1/4 of generalized patients)

Positive Ab titers

Post-synaptic receptor blockade

Bi-modal distribution

Dx: tensilon test, Ach Ab titers, electrodiagnostics

Tx: Ach inhibitor, immunosuppression, management of megaesophagus, plasmapharesis

Question 12

Polymyositis

Answer 12

Generalized weakness, stilted gait, dysphagia, muscle atrophy

Do NOT lose reflexes

Boxers and Newfoundlands

Neoplasia, infectious

Question 13

Masticatory Myositis

Answer 13

Acute: pain on opening mouth, mild exophthalmia

Chronic: masticatory muscle atrophy, non-painful

Dx: Ab to 2M fibers

Tx: immunosupression

Question 14

Muscular Dystrophy

Answer 14

Golden Retrievers

Dx by muscle biopsy

CK 50-80K

Question 15

Neospora

Answer 15

Polyradiculoneutritis, polymyositis

Pre-natal exposure

Muscle atrophy, contracture of PLs

Serum titer for dx

Question 16

Cushing’s myopathy

Answer 16

.

Question 17

Fibrotic myopathy

Answer 17

GSD

Abnormal swing of TL

Progressive fibrosis of caudomedial thigh muscles

Will reoccur if you do sx

Question 18

Feline hyperthyroid myopathy

Answer 18

paresis, ventroflexion, tremors, abnormal gait

T3 and T4 effect sarcoplasm

Question 19

Exercise Induced Collapse

Answer 19

Labs

Collapse, hyperthermia

Otherwise normal

DNM1 mutation

Question 20

DNM-1 mutation

Answer 20

Associated with exercise-induced collapse