peripheral neuropathy

1. Management of Diabetic
Peripheral Neuropathy
Dr. Mahamud Ullah Mahin
Consultant, Orthopedics Department
General Hospital, Barishal.

2. Introduction – what is DPN?
🠶 The presence of symptoms and/or signs of peripheral
nerve dysfunction in people with diabetes after
exclusion of other causes”

3. DPN :- statistics
• ≈70% of diabetics will lose sensation in their feet
• Peripheral sensory neuropathy is the leading factor to diabetic foot
ulcerations
• Approximately 25% of diabetics will develop a foot ulcer
• More than half of all foot ulcers will become infected, requiring
hospitalization and 1 in 5 will require an amputation
• After a major amputation, 30% of patients will have their other limb
amputated within 3 years

4. Simplified view of PNS
🠶 PNS consist of
🠶 Large myelinated fibers, A alpha fibers and A-beta
fibers
🠶 Thinly myelinated fibers (A-delta)
🠶 Unmyelinated fibers, the C fibers.
🠶 Large myelinated fibers
🠶 Serve muscle control as well as touch, vibration,
and position perception.
🠶 Smaller myelinated fibers
🠶 Subserve cold thermal perception and
cold pain.

5. Cont…
🠶 Thin unmyelinated fibers
🠶 Subserve warm thermal perception and pain.
🠶 Autonomic nerve fibers or thin myelinated fibers,
🠶 Regulate heart rate, blood pressure, sweating, and
gastrointestinal and genitourinary function.

6. Peripheral neuropathy
🠶 Loss of nerve fiber function in the peripheral nerves
Normal nerve Abnormal nerve

7. Hyperglycemia Endoneurial Ischemia
Progressive Diabetic Peripheral Neuropathy
Neuronal Injury
Putative Pathogenic Sequence
Impaired Neuronal Regeneration

8. Symptoms of DPN
🠶 Symptoms vary according to the class of nerve fibers
involved.
🠶 The most common early symptoms are induced by
the involvement of small fibers and include
🠶 Neuropathic pain
🠶 May be the first symptom that prompts patients to seek
medical care
🠶 Burning, lancinating, tingling, or shooting (electric
shock–like)
🠶 Occurs with paresthesias
🠶 Typically worse at night

9. 🠶 Neuropathic pain
🠶 Accompanied by hyperalgesia(an exaggerated response to painful stimuli )
and allodynia (pain evoked by contact, e.g., with socks, shoes, and
bedclothes )
🠶 Can lead to interference with daily activities, disability,
psychosocial impairment, and reduced health-related quality of
life
🠶 Symptoms are most commonly experienced in the feet and lower
limbs, although in some cases the hands may also be affected.
🠶 Dysesthesias (unpleasant sensations of burning)

10. 🠶 The involvement of large fibers may cause numbness, tingling
without pain, and loss of protective sensation.
🠶 Patients can also initially present with loss of sensation, numb foot
due to the loss of large fibers.
🠶 Patients frequently state that their feet feel like they are wrapped in
wool or they
are walking on thick socks.

11. Autonomic neuropathy
🠶 Impairs the impaired vasoregulation
🠶 May result in changes to the texture and turgor of the skin,
🠶 causing the dryness and fissuring.
🠶 Dryness predominantly effects the plantar foot.
🠶 Dysregulation of local perspiration may contribute to
increased moisture and increase the risk of fungal
infections.

12. Clinical tests
🠶 The following clinical tests may be used to assess small-
and large- fiber function distal to proximal
🠶 1. Small-fiber function: pinprick and temperature sensation
🠶 2. Large-fiber function: vibration perception,
proprioception, 10-g
monofilament, and ankle reflexes

13. Touch and pressure sensation screening
🠶 Using the 10g Monofilament
🠶 Assess the 4 main areas on the plantar surface of the foot
🠶 i.e, the 1st, 3rd and 5th metatarsal heads and the plantar surface of the
hallux.
🠶 Place the monofilament on each area of the foot
PERPENDICULARLY until the monofilament buckles, and hold for 2
seconds each time with the patient’s eyes closed
🠶 The diagosis of neuropathy is determined if the patient does not feel
1 out of 4 areas tested.

14. Test for vibration loss
🠶 128-Hz tuning fork is used
1. Place the vibrating fork on patient’s distal Hallux
(big toe) joint and ask them if they can feel
vibration
2. If they cannot feel vibration on the hallux
continue checking bony prominences moving
proximally until the patient feels the vibration.

15. Test for temperature sensation
🠶 With Tip-Therm or test tubes,
🠶 One with cold water (5-10°C)
🠶 One with warm water (35 to 45°C).

16. Check for ankle reflexes
🠶 This may be weak in the elderly so it is
not a specific test

17. Diagnosis
🠶 The diagnosis of DSPN is principally a clinical one.
🠶 A combination of typical symptomatology and symmetrical distal sensory loss
Or
🠶 Typical signs in the absence of symptoms in a patient with diabetes is
highly suggestive of DPN
🠶 As up to half of the patients may be asymptomatic, a diagnosis may only be
made on examination or, in some cases, when the patient presents with a
painless foot ulcer.

18. DD’s
Nutritional
B12*
Pyridoxine
Thiamine
Tocopherol
Industrial agents
Acrylamide, Organophosphorous
agents
Drugs
Alcohol, Amiodarone, Colchicine,
Dapsone, Vinka alkaloids,
Platinum,Taxol
Metals
Arsenic, Mercury,
Hereditary
Hereditary motor, sensory, and
autonomic neuropathies
Metabolic disease
Thyroid disease (common)
Renal disease
Systemic disease
Systemic vasculitis
Nonsystemic vasculitis
Paraproteinemia (common)
Amyloidosis
Infectious
HIV
Hepatitis B
Lyme
Inflammatory
Chronic inflammatory demyelinating
polyradiculoneuropathy

19. DD’s
🠶 Consider excluding neuropathy with causes other than diabetes
🠶 By undertaking a family and medication history and performing relevant
investigations (e.g. serum B12, folic acid, thyroid function, complete blood
count, metabolic panel, and a serum proteinimmunoelectrophoresis).
🠶 Electrophysiological testing or referral to a neurologist is rarely needed for
diagnosis, except in situations where the clinical features are atypical, the
diagnosis is unclear, or a different etiology is suspected
🠶 Atypical features that warrant referral include motor greater than sensory
neuropathy, asymmetry of symptoms and signs, and rapid progression.

20. Screening
🠶 Patients with type 1 diabetes for 5 or more years and all patients with type 2
diabetes should be assessed annually
🠶 Using medical history and simple clinical tests.

21. Clinical Impact of DPN
NCVH. Oral Presentations. 2007.
Mortality
Cost
Impairment
Disability
Handicap
Infection
(skin, bone)
Charcot
Foot
Foot
Ulcers
Painful
Neuropathy
Quality of
Life
Sensory
Loss
Surgery,
Amputation

22. Treatment goals
🠶 Good glycemic control
🠶 Symptomatic treatment
🠶 Halt progressive nerve damage

23. Treatment
🠶 Currently available pharmacotherapies primarily consist of
analgesics which provide symptomatic pain control but do not affect
the underlying causes of DPN or its course.
🠶 These include
🠶 TCA
🠶 Amitriptyline , desipramine, imipramine, nortriptyline, maprotiline)
🠶 Anticonvulsants
🠶 pregabalin, gabapentin , sodium valproate, carbamazepine, oxcarbazepine,
lamotrigine, topiramate, lacosamide),
🠶 Serotonin norepinephrine reuptake inhibitors (venlafaxine)
🠶 Opioids (tramadol, oxycodone, dextromethorphan, morphine)

24. 🠶 Medications are currently approved for DPN are:
• Pregabalin
• Duloxetine
• Tapentadol
• Vitamin B1, B6 & B12.

25. Pregabalin
🠶 Analog of GABA
🠶 A calcium channel a2-d subunit ligand
🠶 Has a more rapid onset of action and more limited dosage
range that requires minimal titration.
🠶 Doses- 150 – 600mg/day

26. Duloxetine
🠶 A selective norepinephrine and serotonin reuptake inhibitor.
🠶 Doses of 60 and 120 mg/day showed efficacy in the treatment of
pain associated with DPN

27. Tapentadol
🠶 Tapentadol extended release is a novel centrally acting opioid
analgesic
🠶 It exerts its analgesic effects through both m-opioid receptor
agonism and noradrenaline reuptake inhibition.
🠶 Extended-release tapentadol was approved by the FDA for the
treatment of DPN.
🠶 Due to high risk for addiction and safety concerns compared with
the relatively modest pain reduction, it is not recommended as
first- or second-line treatment.

28. VitaminB1,B6&B12
• Combination of vitamin B1, B6 & B12 shows significant
improvement in diabetic neuropathy through repairing and
regenerating damaged nerves.
• Promotes transmission of nerve impulses and has pain relief
effect.

29. Thankyou