1. Diabetic neuropathy can lead to foot ulcers and amputation, which are preventable with early identification of high-risk feet and appropriate management including education, glycemic control, and offloading of pressure. 2. Neuropathic ulcers are painless and develop on pressure points, while ischemic ulcers cause pain and develop on sides of toes. Neuropathic ulcers usually heal with conservative measures like casting to relieve pressure. 3. Charcot arthropathy is a rare complication where minor trauma can cause bone destruction in joints like the midfoot due to loss of sensation and autonomic dysfunction. Early diagnosis and immobilization are important to prevent deformity.

1. 1
Diabetic Neuropathy in the
Context of Diabetic Foot
Podiatry Workshop
Kuala Lumpur 18 – 19 November 2K
Dr.Ashok Kumar Das
Dean, Director, Prof. and Head
Dept. of Medicine, JIPMER
Pondicherry

2. 2
Diabetic Neuropathy in the
Context of Diabetic Foot - 2
DFU - cause for more amputation than any
other pathology. Is it inevitable?
St. Vincent’s and Health 21 WHO Declaration
have called for reduction in amputation in
diabetic foot.
Most contemporary and challenging issue

3. 3
Diabetic Neuropathy in the
Context of Diabetic Foot - 3
“5-10% of all diabetic patients have foot
ulceration of various degrees and about
1% undergo amputation”
“Diabetes accounts for upto 50% of non
traumatic leg amputations”
“Of all the diabetic amputees about 50%
will lose their life or their other leg by 3
years”

4. 4
Diabetic Neuropathy in the
Context of Diabetic Foot
Foot ulcers result in
*Morbidity
* Mortality
“Enormous health care expenditure”
“Psychosocial problems”
Paucity of data regarding prevalence of
diabetic foot in India

5. 5
Diabetic Neuropathy in the
Context of Diabetic Foot - 5
Neuropathy that is significant enough
to cause foot ulceration may affect 40%
of diabetic population especially elderly
with type 2 diabetes.

6. 6
Indian Patients
Our major problem is neuropathic ulcer
85 - 95 %,
10 – 15% vascular.
-younger patients
-mean age of amputation earlier
- number of amputations for
neuropathic ulcer

7. 7
Indian Context
Eminently preventable
Amputation in a diabetic neuropathic
ulcer is deplorable
Need of the hour
* Awareness/ education
* Early identification of a high risk foot
and its appropriate management

8. 8
Components of neuropathic foot
transforming to diabetic foot - 1
A. Ulcerative diabetic neuropathic foot
components
B. Non-ulcerative neuropathic pathologies
in diabetic foot

9. 9
A. Components of ulcerative
diabetic neuropathic foot - 2
1. Neuropathic foot and Neuroischaemic
foot
2. Neuropathic foot deformities
a. Clawed toes
b. Pes cavus
c. Hallux rigidus and valgus
d. Hammer toe
e. Nail deformities
f. Charcot foot

10. 10
A. Components of ulcerative
diabetic neuropathic foot - 3
3. Neuropathic callus
4. Neuropathic oedema
5. Neuropathic ulcers
a. Callus ulcers
b. Ulcer over the pressure
points on the sole
c. Decubitus ulcers
d. Puncture wound ulcers
e. Traumatic ulcers

11. 11
B. Non-ulcerative neuropathic
pathologies in diabetic foot
1. Charcot Foot
Acute, chronic bone
destruction and
deformed diabetic foot and
toes
2. Pathological fractures
3. Diabetic painful neuropathy

12. 12
DN in context of diabetic foot - 1
Our job – look after “NDF at risk”
A: Preventive measures
Treatment rapid and intensive
Rest
Off load
Antibiotics
Foot wear
Patient education

13. 13
DN in context of diabetic foot - 2
B. Metabolic control
Hyperglycemia
Hypertension
Hyperlipidaemia
Cessation of smoking
C. Deformity management
D. Callus management
E. Debridement and dry skin and fissure
management

14. 14
DN in context of diabetic foot - 3
F. Mechanical control
Off load, Off load, Off load
by rest, crutches, walkers, protective
shoes, heel protective pad, decrease
plantar pressure by removal callus
G. The importance of callus removal in NFU
decrease plantar pressure
know full dimension of the ulcer
deep swab
drainage of exudate, removal of dead
tissue
H. Infection control
I. Educational control

15. 15
Diabetic neuropathy
Scope of the syndrome - 1
Three components of neuropathy:
*sensory – painful, painless
*Motor
*Autonomic
All contribute to diabetic foot ulceration
Asymptomatic neuropathy 35%

16. 16
Diabetic neuropathy
Scope of the syndrome - 2
Diffuse
1. Distal symmetric sensorimotor
polyneuropathy
2. Autonomic neuropathy
A.Sudomotor
B.Cardiovascular
C.Gastrointestinal
D.Genitourinary

17. 17
Diabetic neuropathy
Scope of the syndrome - 3
Focal
1.Cranial neuropathy
2.Radiculopathy/plexopathy
3.Entrapment neuropathy
4.Asymmetric lower limb motor
neuropathy- Diabetic amyotrophy

18. 18
Diabetic neuropathy
Scope of the syndrome - 4
Rather than acting in isolation neuropathy
exerts
Its vicious effects in concert with
angiopathy + immunopathy leading to
infections

19. 19
Neuropathic foot components
Neuropathic ulcer
Neuropathic joint
Neuropathic oedema

20. 20
Diabetic foot – Mechanisms - 1
Loss of pain sensation results in
neuropathic injury due to
repeated unrecognised trauma
inflicted in many different ways

21. 21
Diabetic foot – Mechanisms - 2
Loss of joint positon sense results
in abnormal foot posture
This may lead to injury when
the shoes are not properly selected
or during walking

22. 22
Diabetic foot – Mechanisms - 3
Motor Neuropathy
* Weakness
* Wasting of small intrinsic muscles of
foot
*Imbalance between the flexor and
extensor muscles

23. 23
Diabetic foot – Mechanisms - 4
Intrinsic deformity
Clawing of the toes
Prominence of metatarsal heads
Flattening of the arch

24. 24
Diabetic foot – Mechanisms - 5
Abnormal distribution of body weight
Weight gets concentrated on smaller
areas like metatarsal head and the heel.
Excess pressure loading of these areas
finally results in callus formation.

25. 25
Diabetic foot – Mechanisms - 6
Body weight in patients with plantar ulcers
was significantly greater than in those
with neuropathy but no ulcer.

26. 26
Autonomic neuropathy - 1
* Damages the sympathetic innervation of
lower limb
* This results in
Decreased sweating
Results in dry skin fissures /
cracks
Super added infection

27. 27
Autonomic neuropathy - 2
Opening of arteriovenous channels
Warm skin ( misleadingly healthy )
Shunting of nutrients and oxygen from
the tissues
Impaired vascular response to infection

28. 28
Autonomic neuropathy
classical signs
Dry skin with fissuring
Distended veins over the dorsum of foot
and the ankle

29. 29
Connective tissue changes
Hyperglycemia causes non enzymatic
glycation of collagen and keratin
Increase in cross linking
Become rigid and inflexible
Tissue break down in places where there
is high horizontal shear force

30. 30
Neuropathic ulcer
* Painless
* Develops on pressure points (metatarsal
heads/heel)
* Pulsations intact unless superadded
ischaemia is also present
* Decrease in pain / temperature as also in the
vibration perception
* Punched out ulcer surrounded by callus

31. 31
Neuropathic (n) /Ischemic ulcer (i)
Site Pressure points (n)
Sides / tips of toes (i)
Pain --- ( n ) +++ ( i )
Callus ++ ( n ) --- ( i )
Pulse ++ ( n ) --- ( i )
Abi > 1 ( n ) < .6 ( i )
Healing ++ ( n ) --- ( i )

32. 32
Quantitative tests for
neuropathic assessement - 1
1. Measurement of light touch sensation
- Nylon monofilament (Semmes
Weinstein)
2. Measurement of thermal sensitivity
- Marstock Thermode

33. 33
Quantitative tests for
neuropathic assessement - 2
The advantage of the assessment with
monofilaments or biosthesiometry is the
detection of whether the patient has lost
protective pain sensation that would
render him susceptible to foot
ulceration.
Nylon monofilaments test the threshold
to pressure sensation

34. 34
Quantitative tests for
neuropathic assessement - 3
Monofilament: This is a simple technique.
When applied perpendicular to the foot it
buckles at a force of 10 gms
Areas to be tested include plantar aspect
of big toe metatarsal heads of first, third
and fifth and the plantar surface of heel.
Filament not to be applied over the callus

35. 35
Quantitative tests for
neuropathic assessement - 4
1. Measurement of vibration
*Biosthesiometer
*Graduated tuning fork
2. Nerve conduction studies

36. 36
Management of Neuropathic
Ulcer - 1
General measures
Specific measures

37. 37
Management of Neuropathic
Ulcer - 2
Good glycemic control
Treatment of infections
Management of neuropathic oedema

38. 38
Management of Neuropathic
Ulcer - 3
All ulcers irrespective of their cause will
be slow to heal in presence of oedema,
due impairment of local flow
Neuropathic oedema can be treated with
Diuretics
Ace inhibitors
Ephedrine ( 30 mg tds )
D/d hypo albuminemia cardiac failure

39. 39
Management of Neuropathic
Ulcer - 4
“Over 90% of predominantly neuropathic
ulcers will heal satisfactorily with
conservative measures”

40. 40
Management of Neuropathic
Ulcer - 5
“Key to the management is the relief of
pressure that caused the initial lesion”
Pressure is off loaded most effectively by
encasing the foot in a light plaster of paris
cast.
*Total contact cast
*Removable scotch cast boot, custom
made shoes etc.

41. 41
Preventing Neuropathic Foot
Ulcers - 1
Regular inspection of foot - annually
Identification of high risk feet – 3 mo /
6mo
Careful choice of foot wear
Regular chiropody
Intense education

42. 42
Preventing neuropathic foot
ulcers - 2
“As little as one hour’s education
provided by the podiatrist resulted in
70% reduction in amputations over the
following 2 years . as compared with a
control group who did not receive the
advice”
Malone IM et al 1989

43. 43
Glycemic control and diabetic
neuropathy
Diabetes control and complication trial
showed that intensive insulin therapy
reduced the incidence of appearance of
neuropathy by about 70%

44. 44
Intensive insulin treatment
Reduced the clinical appearance of overt
neuropathy in patients with subclinical
neuropathy from 16% to 7% (57%
reduction)
Reduced the risk of developing clinically
overt diabetic neuropathy by 60% over five
years

45. 45
Neuropathic joint or
Charcot arthropathy - 1
1868 French neurologist I.M. Charcot
First described in tabes
Can also be seen in leprosy,
syringomyelia,
hereditary sensory neuropathy,
Charcot Marie Tooth disease etc

46. 46
Neuropathic joint or
Charcot arthropathy - 2
Relatively rare
Potentially devastating disorder
Long standing diabetes
Dense peripheral neuropathy
Peripheral vascular disease is typically
absent

47. 47
Neuropathic joint or
Charcot arthropathy - 1
Sympathetic failure-- increased blood
flow due to arteriovenous anastomosis
Bone demineralisation (diabetic
osteopenia)
Susceptibility to minor, recurrent fractures

48. 48
Neuropathic joint or
Charcot arthropathy - 4
Painless disintegration of bone in
response to trivial trauma
Common joints involved are
Tarso metatarsal
Metatarso phalangeal
Ankle joint
Knee joint

49. 49
Neuropathic joint or
Charcot arthropathy - 5
Acute Charcot arthropathy may mimic
infection
Chronic Charcot foot is classically
described as ‘bag of bones’
(Gross destruction of joint surfaces and
bone with effusion which is typically
painless)

50. 50
Neuropathic joint or
Charcot arthropathy - 6
Differentiation from osteomyelitis is
difficult
* TC 99 Scan
* Indium labelled white cell scan
* MRI

51. 51
Neuropathic joint or
Charcot arthropathy - 7
Early diagnosis and intervention are important
to prevent deformity and loss of function
Treatment includes
*long term immobilisation in a plaster of Paris
cast
(for upto 1 year)
*Charcot Restraint Orthotic Walker (crow) which
allows pressure to be off loaded
*Pamidronate - tried as a new treatment of
Charcot arthropathy

52. 52
Newer (experimental) measures
for treating neuropathy are
Aldose reductase inhibitors
Gamma linolenic acid
Vasodialators
(ace inhibitors /ca 2+ channel blockers)
Aminoguanidine
Nerve growth factors

53. 53
Management involves
Bed rest
Pressure offloading
Reduction of oedema
Glycemic control
Most important step is the early detection
of a high risk foot by simple tests / few
quantitative tests