Diabetic Neuropathies and Foot

Question 1

What indicates foot ischaemia? What indicates foot neuropathy?

Answer 1

Critical toes and absent foot pulses

Injury or infection over pressure points

Question 2

What are the clinical features of diabetic neuropathy?

Answer 2

Reduced sensation in stocking distribution: test sensation with 10g monofilament fibre
Absent ankle jerks
Neuropathic deformity - Charcot’s joint caused by loss of pain sensation leading to increased mechanical stress and repeated joint injury.
Swelling instability and deformity

Question 3

What should you do if foot pulses are absent?

Answer 3

If absent foot pulses do Doppler pressure measurement

Question 4

What do ischaemia and neuropathy cause? How can you prevent this

Answer 4

Foot ulceration
Educate about daily foot inspection with mirror for the sole, comfortable shoes
Regular chiropody to remove callus, as haemorrhage and tissue necrosis may occur below, leading to ulceration.
Treat fungal infection
Advise not to go barefoot
Promote euglycaemia and normotension

Question 5

Describe diabetic foot

Answer 5

Painless, punched out ulcer in area of thick callus ± superadded infection.

Question 6

What do diabetic foot ulcers cause?

Answer 6

Cellulitis, abscess, osteomyelitis

Question 7

What should you assess in diabetic foot?

Answer 7

Neuropathy (clinically)
Ischaemia (clinically + Doppler ± angiography)
Bony deformity e.g. Charcot joint (clinically + x-ray
Infection (sweats, blood culture, X-ray for osteomyelitis, probe ulcer to reveal depth)

Question 8

What is the management for foot ulceration?

Answer 8

Regular chiropody
Bed rest ± therapeutic shoes
For Charcot’s joint: bed rest/crutches/total contact cast until oedema and local warmth reduce and bony repair is complete. Bisphosphonates may help.

If there is cellulitis, admit for IV antibiotics - staphs streps.
Start empirically with benzylpenicillin IV an fluclox IV ± metronidazole IV.

IV insulin may improve healing

Get surgical help.

Question 9

What are absolute indications for surgery in foot ulceration?

Answer 9

Abscess or deep infection, spreading anaerobic infection, gangrene/ischaemic rest pain, suppurative arthritis.

Question 10

Describe diabetic neuropathy

Answer 10

Symmetric sensory polyneuropathy

Question 11

What is symmetric sensory polyneuropathy? What is management?

Answer 11

Glove and stocking numbness, paraesthesia, pain
Worse at night

Paracetamol –> TCA amitriptyline –> fluoxetine, gabapentin, pregabalin –> opiates
Avoiding weight bearing helps

Question 12

Describe mononeuritis multiplex

Answer 12

E.g. CNIII, CN VI

If sudden or severe, immunosuppression may help - corticosteroids, cyclosporin

Question 13

Describe amyotrophy

Answer 13

Painful wasting of quadriceps and other pelvifemorad muscles

IV immunoglobulins

Question 14

Describe autonomic neuropathy

Answer 14

Postural hypotension (may respond to fludrocortisone), reduced cerebrovascular auto regulation, loss of respiratory sinus arrhythmia, gastropasresis (early satiety, post-prandial bloating, n&v), urinary retention, erect dysfunction, gustatory sweating, diarrhoea.

Question 15

What common organisms in diabetic foot ulcer and what antibiotics used?

Answer 15

Saphyloccous aureus
Streptococci
Anaerobes

Benzylpeniccilin
Flucloxacillin
Metronidazole

Question 16

What is Charcot’s joint?

Answer 16

Neuropathic deformity - claw toes, pes caves, loss of transverse arch, decker-bottom sole
Caused by loss of pain sensation leading to increased mechanical stress and repeated joint injury.
Swelling instability and deformity

Question 17

What features suggest osteomyelitis in Charcot’s joint?

Answer 17

Redness, fever, weakness