Acquired Peripheral Neuropathies

Question 1

What is the most common type of neuropathy?

Answer 1

axonopathy

Question 2

What pattern of weakness would suggest a demyelinating neuropathy?

Answer 2

proximal weakness

Question 3

Is motor or sensory loss more predominant in an axonopathy?

Answer 3

sensory > motor

Question 4

Is motor or sensory loss more predominant in a demyelinating neuropathy/

Answer 4

motor > sensory

Question 5

What are the typical clinical features of a sensory neuronopathy?

Answer 5

proprioceptive loss, tremor, ataxia

Question 6

What are the typical clinical features of a small fibre neuropathy (e.g. diabetes, amyloid, Fabry)?

Answer 6

pain and autonomic features

Question 7

What investigations should be ordered first line for a peripheral neuropathy?

Answer 7

FBE, UEC, LFT, HbA1c, TFT, B12, folate, SPEP, UPEP, ESR, auto antibodies

Question 8

What are the findings on nerve conduction studies for an axonopathy?

Answer 8

reduced or absent sensory potentials in a length dependent pattern, lower > upper limbs
low amplitude distal motor responses, mildly delayed F waves
mildly reduced conduction velocities

Question 9

What are the EMG findings for an axonopathy?

Answer 9

neurogenic, distal > proximal muscles
fibrillations, positive sharp waves at rest
motor units: high amplitude, long duration, polyphasic, rapid firing

Question 10

What are the findings of nerve conduction studies for a demyelinating neuropathy?

Answer 10

very slow conduction velocity
very prolonged distal latencies and F waves
conduction block

Question 11

What are the EMG findings for a demyelinating neuropathy?

Answer 11

reduced motor unit recruitment

but the motor unit themselves may be normal

Question 12

A sural nerve biopsy is useful to diagnose what conditions?

Answer 12

vasculitis
amyloidosis
sarcoidosis
leprosy
tumour infiltration

Question 13

What is the difference in treatment for GBS vs CIDP?

Answer 13

Use steroids in CIDP