Nerve, muscle and NMJ pathology

Question 1

What is the cause of Lambert eaton syndrome?

Answer 1

autoimmune often have underlying malignancy

Question 2

What is the cause of myasthenia gravis

Answer 2

autoimmune

Question 3

What is the cause of Duchennes muscular dystrophy?

Answer 3

Genetic

Question 4

What is a paraneoplastic syndrome?

Answer 4

confusing, diverse range of conditions caused by malignant tumours (caused by different substances tumours secrete)

Question 5

What is motor neurone disease?

Answer 5

• progressive degeneration of upper and lower motor neurone

- unknown cause

Question 6

What are the symptoms?

Answer 6

• difficulty moving limbs + weakness
• speaking
• swallowing
• breathing

Question 7

What is the cause of motor neurone disease?

Answer 7

idiopathic

Question 8

What nerves are usually affected in MND?

Answer 8

both upper and lower motor neurones

Question 9

What part of the NMJ does Lambert eaton affect?

Answer 9

Ca2+ channels on the motorneurone

- autoantibodies against the calcium channels

Question 10

What are the symptoms of Eaton Lambert syndrome?

Answer 10

• muscle weakness
• hyporeflexia
• arefelxia
• autonomic dysfunction

Question 11

What is the most common cancer causing Lambert eaton?

Answer 11

lung cancer (specifically small cell carcinoma)

Question 12

What autoantibody is present in myasthenia gravis?

Answer 12

autoantibodies for Ach receptors

Question 13

Why is thymus relevant to MG?

Answer 13

removal of thymus gland as can be hyper plastic in MG, can reduce symptoms (due to involvement with T cell maturation)

Question 14

What organ is often enlarged n MG?

Answer 14

hyperplasia of thymus

Question 15

What tests should be done to diagnose polymiositis?

Answer 15

• muscle biopsy
• blood test for autoantibodies
• lots of different autoantibodies can be present

Question 16

What are the symptoms of polymiositis?

Answer 16

• chronic muscle inflammation

- chronic muscle weakness

Question 17

What histology would support rheumatoid arthritis?

Answer 17

lymphocytic infiltration

Question 18

How is Duchennes muscular dystrophy inherited?

Answer 18

X-chromosome linked

Question 19

What protein is involved in Duchennes muscular dystrophy?

Answer 19

dystrophin which is an important cell membrane protein in muscle cells

Question 20

What histological findings would be seen in Duchennes muscular dystrophy?

Answer 20

by endstage fatty infiltration

Question 21

Why is Duchennes muscular dystrophy described as causing pseudo hypertrophy?

Answer 21

muscle is enlarged but due to fatty infiltration not muscle atrophy

Question 22

Why is Duchennes muscular dystrophy described as causing pseudo hypertrophy?

Answer 22

muscle is enlarged but due to fatty infiltration rather than muscle growth

Question 23

What are the symptoms of MG?

Answer 23

• non-constant muscle weakness
• often affects eyes and face first
• triggered by stress, infections and medication
• droopy eyelids, double vision

Question 24

What are the symptoms of Duchennes muscular dystrophy?

Answer 24

• enlarged calf muscles
• delayed motor development
• muscle weakness progressive
• waddling gait
• cardiomyopathy