Neuromuscular Diseases Flashcards Preview

AP: Cumulative > Neuromuscular Diseases > Flashcards

Flashcards in Neuromuscular Diseases Deck (45):
1

What are upper motor neurons?

Motor neurons that originate in the cerebral cortex and carry motor information to a lower motor neuron

2

What is a lower motor neuron?

A motor neuron that connects upper motor neuron's to the end muscle

3

How are upper motor neuron lesions characterized?

Spasticity
Paralysis
Weakness
Hyperactive reflexes

4

How are low work motor neuron lesions characterized?

Fasciculation
Paralysis
Weakness
Atrophy
Flaccid reflexes

5

What is the main difference between upper motor neuron lesions and lower motor neuron lesions in terms of paralysis

Upper motor neuron lesions cause spastic paralysis
Lower motor neuron lesions cause flaccid paralysis

6

What is the purpose of Myelin?

Speeds neuronal signal conduction

7

What is myelin?

And electrically insulating phospholipid layer that surrounds axons of neuron's

8

What type(s) of cells supply the myelin for peripheral and central nerves?

Schwann cells = peripheral nerves
Oligodendrocytes = CNS

9

An auto immune disease with antibodies against the acetylcholine receptors of the motor end plate is known as...

Myasthenia gravis

10

What is the clinical hallmark of myasthenia gravis?

Skeletal muscle weakness worsens with activity and improves with rest

11

What does the severity of myasthenia gravis depend on (in terms of the antibodies)?

The ability of the antibodies to decrease the number of available acetylcholine receptors

12

The bulbar region has an effect on what parts/functions of the human anatomy?

Facial control
Airway control
Swallowing

13

Myasthenia gravis has a correlation with which gland?

Thymus glands are often hyperplastic in Myasthenia gravis patients

14

What are some of the exacerbating factors of myasthenia gravis?

Vaccinations
Infection
Stress
Pregnancy
Increased temperature

15

Are newborns of myasthenia gravis mothers at risk for respiratory failure? if so, why?

Yes. Acetylcholine receptor antibodies cross the placenta.

16

What are some of the anesthetic considerations for patients with myasthenia gravis?

-Bulbar involvement (Aspiration risk)
-Respiratory weakness
-Decreased response to succinylcholine
-Prolonged effects of nondepolarizing muscle relaxants
(Worse with inhaled anesthetics, Magnesium and Aminoglycosides)

17

List the four post op risk factors for mechanical ventilation in myasthenia gravis patients?

Having the disease > 6 years
Chronic respiratory disease
Pyridostigmine dose > 750 mg/day
Preop vital capacity < 2.9 L

18

What is a myasthenic crisis?

An exacerbation of myasthenia gravis characterized by muscle weakness and respiratory insufficiency

19

What type of test can differentiate between a cholinergic crisis and a myasthenic crisis and how does it work?

Tensilon test: Give a little anti-cholinesterase
Pt gets better = myasthenic
Pt gets worse = cholinergic

20

What is myasthenic syndrome and what is another name for it?

Myasthenic syndrome (Lambert Eaton syndrome)
-Antibodies attack calcium gated channels at presynaptic nerve terminals to decrease the release of acetylcholine

21

Differentiate between the physical symptoms of myasthenia gravis and myasthenic syndrome

MG: Worse with activity
-Symptoms move from the top down
-Very sensitive to non-depolarizer's
-Treated with anti-cholinesterase drugs

MS: Improves with activity
-Symptoms start in the legs and move up
-Sensitive to both depolarizer's and non-depolarizer's
-Anti-cholinesterase drugs have no benefit

22

Lou Gehrig's disease is also known as

Amyotrophic lateral sclerosis (ALS)

23

Death in ALS usually results from what?

Pulmonary infections

24

What is ALS?

The loss of nerve cells in the anterior horn of the spinal cord and lower brainstem

(Effects MOTOR not SENSORY)

25

ALS is characterized by

Atrophy
Weakness
Exaggerated reflexes
Late stages--Pharyngeal, laryngeal, and respiratory muscles affected

26

What are some of the anesthetic considerations for an ALS patient?

High aspiration risk
Abnormal PFTs
No succ
Sensitive to nondepolarizing agents
Regional if possible

27

What is multiple sclerosis?

An autoimmune disease that results in the demyelination of neuron's in the brain and spinal cord

28

What are some factors that increase the risk for multiple sclerosis?

Two times as common in females
20 to 40 years of age
Familial tendency
Increasing latitude

29

What are some of the anesthetic considerations for patients with multiple sclerosis?

Sensitive to local anesthetics
No succ
Don't overheat
Autonomic lability
Resistant to non-depolarizer's
No spinal's

30

What is muscular dystrophy?

A hereditary disease caused by abnormality in dystrophin

-Muscle wasting without denervation

31

What is the most common form of muscular dystrophy and how is it contracted?

Duchenne's muscular dystrophy is an X-linked recessive disease characterized by elevated creatinine kinase levels

32

Lab results will show an increase in what for Duchenne's muscular dystrophy patients?

Creatinine kinase levels

33

What are the primary characteristics of Duchenne's muscular dystrophy?

Presents 3 to 5 years of age
Proximal muscle weakness
pseudo-hypertrophy of calf muscles
Abnormal gait
Intellectual impairment
Relentless progression
Severe kyphoscoliosis
Severe bulbar symptoms
Pulmonary HTN due to OSA
Death by 20 to 30 years of age

34

What are some important in aesthetic considerations for muscular dystrophy patients?

-Increased incidence of MH (no sux or inhalational agents)
-Respiratory issues (Bulbar symptoms and restrictive pulmonary disease)

35

List three other types of muscular dystrophy and one drug that should be avoided in all cases

Beckers
Facioscapulohumeral dystrophy
Limb-girdle dystrophy

NO SUCCINYLCHOLINE

36

Why is succinylcholine contraindicated in patients with neuromuscular diseases or those who have been immobile for extended periods of time?

These patients developed extra junctional receptors along the muscles
-More receptors for sux to bind to and cause hyperkalemia

37

Guillain-Barre syndrome is also known as?

ACUTE demyelinating polyneuropathy

38

How is Guillain-Barre syndrome characterized?

Sudden onset of ascending motor paralysis
Immune mediated against myelin of peripheral nerves
Severe autonomic dysfunction

39

What are some anesthetic considerations for Guillain-Barre?

Bulbar muscle involvement-Aspiration
Autonomic lability
No sux
Regional controversial

40

What is the recommended dose for succinylcholine in myasthenia gravis patients?

2x normal or 2.6x normal for intubation

41

What is the recommended dose for nondepolarizing agents in myasthenia gravis patients?

Not recommended (extreme sensitivity)

42

Discuss the role of temperature on nerve conduction in multiple sclerosis patients?

Increased temperature
decreases conduction

43

What is the abnormal protein in muscular dystrophy?

Dystrophin

44

What other disease has a similar defect to muscular dystrophy?

Malignant hyperthermia

45

Guillan-Barre Syndrome is usually seen after what type of illness?

Viral
-Also has an association with Hodgkin's and HIV