Peripheral Neuropathies and Myopathies

Question 1

What infections is GBS most commonly associated with?

Answer 1

• Campylobacter
• CMV
• EBV

Question 2

Describe the clinical features of GBS

Answer 2

• symmetrical distal polyneuropathy
• sub-acute onset (1-4 days)
• initial paraesthesia in legs, thighs and buttocks
• early progressive flaccid weakness
• facial and bulbar weakness

Question 3

What are the most appropriate investigations for GBS and what would they show?

Answer 3

• Nerve conduction studies = early conduction block
• Bloods = anti-ganglioside antibodies
• LP = increased protein

Question 4

How is GBS managed?

Answer 4

• supportive care

- consider plasma exchange/IV immunoglobulins

Question 5

Describe the classical clinical features of CMT

Answer 5

• symmetrical muscle weakness and atrophy
• inverted champagne bottle legs (atrophy of peroneal muscles)
• pes cavus

Question 6

What is the most appropriate investigation for CMT?

Answer 6

Nerve conduction studies = decreased velocity

Question 7

What are the clinical features of alcoholic neuropathy?

Answer 7

• chronic
• mixed motor and sensory
• pain, numbness, burning, paraesthesia
• symmetrical distal polyneuropathy beginning distallya nd spreading

Question 8

What are the 5 most common causes of symmetrical distal polyneuropathy?

Answer 8

1) Diabetes
2) Alcohol abuse
3) B12 deficiency
4) GBS
5) CMT

Question 9

What are the 3 most common causes of predominantly motor peripheral neuropathies?

Answer 9

1) GBS
2) CMT
3) Multifocal motor neuropathy

Question 10

When is EMG indicated? What does it show?

Answer 10

Differentiating between muscle denervation and myopathy
Denervation = fibrillation, large, polyphasic potentials
Myopathy = small, polyphasic potentials

Question 11

Give 2 inflammatory causes of acquired myopathy

Answer 11

1) polymyositis

2) dermatomyositis

Question 12

Name 3 groups of inherited myopathies and an example of each

Answer 12

1) Musclar dystrophies (e.g. duchenne, becker)
2) Myotonias (e.g. myotonia congenita)
2) Channelopathies (e.g. Calcium channelopathy)

Question 13

Describe 3 negative symptoms seen in myopathy

Answer 13

• weakness
• atrophy
• fatigue

Question 14

Describe 4 positive symptoms seen in myopathy

Answer 14

• cramp (short, involuntary contractions)
• contracture (long, involuntary contractions)
• myotonia (impaired relaxation after contaction)
• myalgia

Question 15

What are the main features of Duchenne muscular dystrophy?

Answer 15

• Proximal muscle weakness and wasting

- Cardiomyopathy