Peripheral neuropathies

Question 1

Classify the different types of peripheral neuropathies

Answer 1

Radiculopathy: nerve roots
Plexopathy
Distal neuropathy: distinct peripheral nerves
-Mono: nerve injury or compression
-Multi: leprosy
-Poly (symmetrical): diabetes, alcohol, hereditary

Question 2

Describe the features of acute axonal interruption peripheral neuropathy

Answer 2

Acute axonal interruption: occurs after nerve division

• immediate complete sensory and motor loss
• distal segments (crushed/severed) will degenerate
• muscle fibres degenerate if nerve conduction not recovered within 2 years

Question 3

What are the clinical features of peripheral neuropathies

Answer 3

Paraesthesiae
Numbness or restless legs
Weakness or loss of balance when walking

Progressive deformity: motor neuropathies
Trophic skin changes
Ataxia
Charcot joints

Question 4

Describe the clinical features of diabetic neuropathy

Answer 4

Early symmetrical numbness and paraesthesia in glove and stocking distribution
Motor loss: claw-toes and high arches -> plantar ulcers
Charcot joints: most commonly affects the midtarsal joints, MTP, and ankle joints

Question 5

Name the 4 components of diabetic foot

Answer 5

Peripheral vascular disease: ulceration, gangrene
Peripheral neuropathy: ulceration, charcot joint
Infection after minor trauma
Osteoporosis: insufficiency fractures, charcot joint

Question 6

Describe the features of chronic axonal degeneration peripheral neuropathy

Answer 6

Chronic axonal degeneration: non-traumatic

• slow and progressive sensory and motor loss
• some conditions may predominantly be sensory (diabetes), whilst others motor
• glove and stocking distribution
• altered reflexes and ataxia, muscle weakness/wasting

Question 7

Describe the features of demyelination peripheral neuropathy

Answer 7

Demyelination: nerve entrapment and blunt soft tissue trauma

• slowing of conduction +/- complete nerve block
• sensory and motor dysfunction distal to lesion
• potentially reversible within 6 weeks
• Demyelinating polyneuropathies rare, except Guillain-Barre syndrome

Question 8

What is the speed of axonal regeneration?

Answer 8

Axonal regeneration is slow (1 mm/day) and often incomplete.

Question 9

Outline the prophylactic management of ulceration in diabetic foot

Answer 9

Specialist diabetic foot clinic with MDT
Regular foot inspection
Wide-fitting footwear
Nail care with chiropody
Debridement of calluses
Keep foot cool
Avoid walking barefoot

Question 10

Define acute brachial neuritis

Answer 10

Unusual cause of severe shoulder girdle pain and weakness due to parainfectious disorder of one or more of the cervical nerve roots and brachial plexus.

History of viral infection or antiviral inoculation.

Question 11

How does acute brachial neuritis present?

Answer 11

Severe shoulder girdle pain and weakness
Sudden onset, constant
May extend into neck and hand
Usually lasts 2-3 weeks

Paraesthesia: arm or hand
Weakness: shoulder, forearm, hand
-winging of scapula and wrist drop may occur

Question 12

Define Guillain-Barre syndrome

Answer 12

Acute demyelinating motor and sensory polyneuropathy, usually 2-3 weeks after an URTI or Gi infection.

Question 13

Define Leprosy

Answer 13

Mycobacterium leprae inection causing a diffuse inflammatory disorder of skin, mucous membranes, and peripheral nerves.

Question 14

How can leprosy present?

Answer 14

Tuberculoid leprosy causes the most severe lesions. Anaesthetic skin patches develop over extensor surfaces. Loss of motor function -> weakness and deformity of hands and feet.