3. Neuromuscular Junction Disorders

Question 1

Botulism- Presynaptic!!!!

Answer 1

Found in improperly preserved or canned foods & contaminated wounds
Neurotoxin produced by clostridium botulinum
Anaeobic, gram positive rod

Question 2

Classification/ aquistion

Answer 2

Food bourne (HONEY)
Wound
Unclassified

Question 3

Mechanism

Answer 3

Botulinum toxin enters presynaptic terminals
Blocks the fusion of ACh vesicles with PRESYNAPTIC membrane (myoneural junction)
Inhibit ACh release into neuromuscular junction
Nerve impulse fails to transmit across the neuromuscular junction
Muscle paralysis

Question 4

Botulism- Timeframe

Answer 4

12-36 hrs after ingestion of contaminated food

Question 5

Botulism Signs and Symptoms

Answer 5

Flaccid symmetrical paralysis
Blurred & double vision, photophobia, ptosis(drooping of eyelid)
Dry mouth, nausea, & vomiting
Lethargy
Difficulty in swallowing (dysphagia) & speech (dysarthria)

Question 6

Botulism- sensory

Answer 6

NO SENSORY INVOLVEMENT

Question 7

Prevention

Answer 7

Boiling food 10 min
Avoid honey for children <1
Wound care and sterile technique

Question 8

Botulism Recovery

Answer 8

sprouting of new terminal nerve filaments and formation of new synapses

Question 9

BoTox as a treatment for Spasticity

Answer 9

SCI
MS
CVA
TBI

Question 10

BoTox Mechanism

Answer 10

Prevent the release of acetylcholine from the PRE-SYNAPTIC nerve terminal, thus blocking peripheral cholinergic transmission at the neuromuscular junction

Question 11

BoTox active time

Answer 11

3-4 months

Question 12

BoTox taking effect

Answer 12

Taken up at NMJ within 12 hr

Effect ovvurs over 4-7 days

Question 13

Plan of care after botox

Answer 13

ACTIVE STRETCHING- Reciprocal inhibition
Strengthening of opposite muscles
Dynasplint or some sort of passive stretching can help
Don’t have a lot of time before wears off

Question 14

Post injection

Answer 14

PT MANDATORY
Splinting
Dont overstretch
Increase strength of antagonist

Question 15

BoTox Side effects

Answer 15

Swallowing
Speaking
Breathing
Drooping eyelids

Question 16

Myasthenia gravis- POSTSYNAPTIC

Answer 16

large muscle weakness

Post synaptic disease at NMJ

Question 17

Myasthenia gravis Mechanism

Answer 17

Widened synaptic cleft
Loss of folds – muscle endplate membrane
Reduction in number and density of ACh receptors
Results in weakness or paresis
*****ACH neurotransmitter is less likely to find a receptor before it is hydrolyzed by ACHesterase

Question 18

Mysathenia gravis drug treatment

Answer 18

target the breakdown of neurotransmitter to slow it down providing more time to find a receptor

Question 19

Myasthenia gravis- THYMUS

Answer 19

acquired autoimmune
viral infection
hyperplasia of thymus (70)
tumors of thymus (10)

Question 20

Myasthenia gravis prevalence

Answer 20

BIMODAL
Female peak young (15-30)
Male peak (60-75)
Greater in females

Question 21

Myasthenia gravis disease progression

PROXIMAL TO DISTAL

Answer 21

maximal weakness within a year in 2/3 cases

after 15-20 years, weakness is fixed

Question 22

myasthenia gravis remission

Answer 22

25%

Question 23

classifications of myasthenia gravis

Answer 23

Ocular (10-15)

Generalized (85)

Question 24

Myasthenic crisis

Answer 24

respiratory failure

Question 25

Byasthenia gravis Signs and Symptoms

Answer 25

``` Ptosis Diploplia facial weakness (CNVII) Oropharyngal weakness Swalling difficulties ```

Question 26

Therapy for myasthenia gravis

Answer 26

Schedule therapy in A.M. to get the most out of therapy, want to see patients in P.M. to understand how severe their condition gets Less aggressive physical activity toward the end of the treatment or HEP instruction, do harder activities first when they’re in peak PRIMARILY MUSCULAR DISEASE (neuromuscular junction), rarely have sensory dysfunction Have patients swallow with chin tucked to avoid aspiration Don’t speak with food in mouth Monitor tidal volume, vital capacity, and inspiratory force during PT

Question 27

Myasthenia gravis weakness and impportant info

Answer 27

BUE or BLE (proximal > distal) Respiratory muscles Better in A.M., declines as the day progresses (or declines during exercise)

Question 28

Myasthenia gravis diagnosis

Answer 28

presence of circulating antibodies to ACH receptors Muscle biopsy to count ACH receptors Decremental response to repeated stim

Question 29

Myasthenia gravis diagnosis | TENSILON TEST``

Answer 29

Give tensilon Compare performanc on/off/placebo IF STRENGTH/ENDURANCE IMPROVE ON THEN ITS MG

Question 30

Tensilon MOI

Answer 30

Mainly diagnostic | hydrolyzes ACh so it stays in the synapse longer

Question 31

Myasthenia gravis intervention drug treatment

Answer 31

``` Anticholinesterae Immunosuppressives IVIG Plasmaphoresis Thymectomy- adults ```