diabetic peripheral neuropathy signs and symptoms

1. DIABETIC PERIPHERAL
NEUROPATHY
Dr N.PRABAKARAN

2. Objectives
• Definition
• Risk factors
• Pathogenesis
• Classification
• Test
• Management
• Conclusion

3. 55 year old gentleman who is a known patient with type 2 diabetes for 15
years presented with a history of inability to sleep at night due to persistent
pricking sensation of both his feet which was worrying for 6 months. On
examination , his feet were normal , monofilament recorded 10g in both
feet and biothesiometer read 40 volts bilaterally. Both fundi showed severe
non proliferative diabetic retinopathy. Systemic examination was normal .
He has been on glibenclamide 10mg twice daily and metformin 1g thrice
daily . His HbA1C was more than 12%.All of the following are true except:
• A . Peripheral neuropathy is an indication to start him on insulin.
• B. Best option is to add another oral hypoglycemic agent for better control
of his sugars.
• C. Microcellular rubber footwear should be ideally prescribed for his
neuropathy.
• D.He might require long term insulin therapy.
• E. Severe NPDR is an indication for insulin therapy.

4. DEFINITION
• Peripheral neuropathy is defined as presence of symptoms and /or
signs of peripheral nerve dysfunction in people with diabetes.
• Most common symptomatic complication of diabetes.
• It is characterized by a decline and damage of nerve function leading
to loss of sensation,ulceration and subsequent amputation.

5. Risk factors
• Poor glucose control
• Long duration of diabetes
• Damage to blood vessels
• Autoimmune factors
• Genetic susceptibility
• Lifestyle factors:
Alcohol , smoking , low HDL , cardiovascular disease.

6. Pathogenesis
Metabolic hypothesis:
Persistant hyperglycemia and insulin deficiency  alteration in
sorbitol pathway  increased advanced glycosylated end product
formation  increased oxidative stress  nerve dysfunction.
Immune hypothesis:
Autoantigen that induce immune response APLA,antibodies to
gangliosides

7. Microvascular hypothesis:
Impaired vasoconstriction and vasodilatation absolute/relative
ischemia in nerve
Neurotrophic hypothesis:
NFG,neurotrophin 3,4/5,IFG-1 are necessary for survival of neuron are
deficient in hyperglycemic individuals
Oxidative stress hypothesis:
Hyperglyemia increased free radical formationendothelial cell
dysfunction and neurotoxic effectnerve damage.

8. Classification
Symmetric polyneuropathies
-Sensory or sensorimotor polyneuropathy
-Selective small fiber polyneuropathy
-Autonomic neuropathy
Focal and multifocal neuropathies
-Cranial neuropathy
-Limb mononeuropathy
-Trunk mononeuropathy
-Mononeuropathy multiplex
-Asymmetric lower limb motor neuropathy

9. Distal symmetric polyneuropathy

10. Cranial neuropathies
• EOM- diabetic>non diabetic
• >50yrs,abrupt,painless a/w headache
• 3rd
cranial nerve(sparing pupil) –mc
• 4th
cranial nerve –least common
• 6th
cranial nerve-may be involved with other CN.
• Facial palsy in diabetes-relationship uncertain
• No specific treatment, gradual recovery typically occurs.

11. Limb Mononeuropathies
Compression and entrapment neuropathy
• Slowly developing lesion---pain+weakness
• Incidence diabetic=nondiabetic
• Median nerve (carpal tunnel syndrome)-mc
• Symptomatic carpal tunnel 11%in T1DM,6%T2DM
• Asymptomatic carpal tunnel much more common
• Ulnar neuropathy at elbow occurs as well.
• Treatment empirical,conservative or surgical

12. Nerve infarctions
• Abrupt and painful
• Radial nerve result in wrist drop
• Peroneal nerve-foot drop
• Femoral nerve-quadriceps weakness
• Lateral femoral cutaneous nerve-meralgia paresthetica
• Electrodiagnostic test reveals axon loss
• Recovery takes month to years depend on the extent of axon loss and
site(proximal vs distal)
• Distal muscle recovery is often incompletely
• No specific treatment for limb mononeuropathy
• If multiple nerves are affected it result in mononeuropathy multiplex
• Immunomodulating therapy advocated for mononeuropathy multiplex

13. Truncal Mononeuropathy
• Pain around abdomen or lower chest
• Cutaneous hyperesthesia
• Restricted form of diabetic radiculopathy
• Paraspinal muscle denervation on EMG
• Once structural abnormalities are ruled out
• Treatment –pain management
• Gradual improvement generally occurs.

14. Asymmetric lower limb motor neuropathy
• Type 2DM,male >50 yrs,weight loss
• Pain in lower thoracic and upper lumbar nerve roots.
• Pain worst at onset and gradually subsides.
• Paresthesia and hyperesthesia are common
• Painweakness in upper leg
• o/e L2-L4 distribution weakness seen
• Weakness involves iliopsoas,quadriceps,adductor
sparing hip extensors and hamstrings.

15. • Weakness usually unilateral or bilateral,when bilateral it is frequently
asymmetric
• Sensory loss is mild mainly in distal
• Knee/ankle jerks are absent in most patients
• Progression of sign and symptom varies it can be as short as 1-2 weeks or
as long as year or more
• Most patient –improvement of pain or dysesthesia
• Recovery of motor function is often incomplete ,slower,takes up to 18
months
• Etiology is microscopic vasculitis producing nerve ischemia,with multifocal
involvement of lumbosacral roots,plexus and peripheral nerve ,hence it is
termed as diabetic lumbosacral radiculoplexus neuropathy.
• Treatment – controlling diabetes.

16. Chronic inflammatory demyelinating
polyneuropathy
• It is acquired immune mediated inflammatory disorder of PNS
• It is chronically progressive or relapsing symmetric sensorimotor
disorder with cytoalbuminologic dissociation and interstitial and
perivascular endoneurial infiltration by lymphocytes and
macrophages.
• It is considered to be chronic variant of AIDP ,the most common form
of guillian barre syndrome.
• These patient present with limb weakness(proximal and distal) which
is often proceded by infective illness.

17. • A proportion of patient also have sensory and autonomic dysfunction
• CIDP must be treated to prevent accumulating disability that
nescessitates physical and occupational therapy,orthotic devices and
long term treatment
• Main stay of treatment is immunosuppressive or immunomodulatory
intervention.

18. Treatment induced neuropathy in diabetes
• Acute onset of neuropathic pain and/or autonomic dysfunction within 8 weeks
of large improvement in glycemic control specified as decrease in more than 2%
HbA1C over 3 months.
• Poor glucose control and rapid treatment of hyperglycemia can be associated
with increased risk of neuropathy
• Insulin neuritis was considered rare cause for acute neuropathy
• It is most common in T1DM treated with insulin,but it can occur in any type
where there is rapid correction either with insulin or OHAs.
• Hemodynamic changes (AV shunting) resulting in endoneurial hypoxia of small
fibers.
• Symptoms are less responsive to opioids.

19. Assessment

21. Management
Small fiber neuropathy
Daily foot inspection
Microcellular rubber footwear
Shoe should fit well
Avoid exposure to heat
Creams for skin drying and cracking
After bathing feet should be dried
Nails should be cut transversely

22. Large fiber neuropathy
• Gait and strength training-
Diabetic patient with large fiber neuropathy have increased
predisposition to falls due to ataxia,incoordination,weakness and
muscle wasting.Improving muscle strength by high intensity strength
training,coordination and balance
• Microcellular rubber foorwear

23. Management aimed at symptoms
Superficial pain
• Tricyclic antidepressant-C/I CVD,BPH,Narrow angle glaucoma
s/e anticholinergic effect,orthostatic hypotension,ED limit it usage.
• Anticonvulsants-except phenytoin
• Carbamazepine,gabapentin,pregabalin
• Topiramate –shows promising results causes growth of intraepidermal
nerve fiber used at dose of 25-50mg/day
• SSRI and SNRI –Fluoxetine<Duloxetine

24. • Deep seated pain
• Opioid derivatives-tramadol+paracetamol
• Transcutaneous electrical nerve stimulation
• Local application of capsaicin oinment

25. Nonpharmacological treatment
• TENS
• Electrical spinal cord stimulation
• Percutaneous electrical nerve stimulation
• Magnetic field therapy
• Low intensity laser therapy
• Monochromatic near infrared treatment
• Electroacupuncture
• Exercise
• Psychological therapy

26. Conclusion
• Important complication of uncontrolled hyperglycemia
• DPN is common and costly disease
• Weight loss and exercise are helpful in both diabetic and prediabetic
• Prevention of ulcers and falls
• Educating patient about MCR footwear,periodic foot examinations
and intensive podiatric care
• Primary prevention start with fall risk assessment,education,referral
to physical therapy

27. Reference
• Harrison's Principles of Internal Medicine, 21e
• A Practical guide to diabetes mellitus
• www.uptodate.com/diabetic-neuropathy