Post on 16-Jul-2015
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Diabetic Neuropathy
Dr Shahjada SelimAssistant Professor
Department of Endocrinology
Bangabandhu Sheikh Mujib Medical University
Dhaka, Bangladesh
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Global Situation Prevalence: 22.7% T1DM, 32.1% T2DM USA: 17% of costs of treating diabetic
complications (approx $300 per patient per year)
UK: £13 million p.a on diabetic foot complications
1. Young MJ, Boulton AJ, MacLeod AF, Williams DR, Sonksen PH. Diabetologia 1993;36(2):150-4.
2. Caro, J. J., A. J. Ward, et al. (2002). Diabetes Care 25(3): 476-81.
HISTORY• 1864-Marchal de calve -DM affects nervous sys
• 1890-Buzzard -motor weakness
• 1893-Leyden -classification
• 1936-Jordan -autonomic neuropathy
• 1947-1973 Pirart -25 yr prospective study
• Dyck & co -Rochester diabetic neuropathy study
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Pathology
Axonal loss, focal demyelination & regeneration
↓ conduction velocity and ↑ sensory thresholds
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Risk Factors
Glycaemic control-DCCT ↑ with age: 5% 20-29 years, 44.2% 70-79
years > 50% T2DM >60 years of age ↑ with duration of diabetes: 20.8% < 5years,
36.8%>10 years ↑ Smoking ↑ Microalbuminuria ↑Height ? Nutritional factors
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Presentations
3 types of neuropathy:
1. Progress steadily with increasing duration of diabetes and associated with other diabetic complications-common
2. Acute onset with resolution over period of months-rare
3. Pressure palsies
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Presentations
Diffuse symmetrical sensorimotor polyneuropathy
Predominantly sensory Predominantly feet ↓ pain and temperature sensation Parasthesiae and numbness Neurogenic pain/allodynia Neuropathic oedema Wasting occurs only if severe
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Diffuse symmetrical sensorimotor polyneuropathy
Problems: Pain and oedema Diabetic foot ulceration
Present in 80% of foot ulcers Principle cause in 39% of ulcers Partly responsible in 36% of ulcers
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Autonomic Neuropathy Closely associated with sensorimotor
neuropathy Signs are common if looked for (40%
subjects have abnormal CVS tests) but symptoms are rare (<1%)
Affects the response to hypos but not awareness
If symptoms: mortality=30-50% over 10 years
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Diffuse Small Fibre Neuropathy
T1DM Young, ♀ > ♂ Selective damage to small nerve fibres Pain and temp lost but LT retained Symptomatic autonomic neuropathy,
Charcot arthropathy and foot ulcers ? autoimmune
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Mononeuropathies
Acute ? Secondary to ischaemia Pain and weakness (severe) Resolve over months
Amyotrophy (Older > )♂ ♀ 3rd nerve 6th nerve Truncal radiculopathies
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Insulin Neuritis
Acute & diffuse May be painful Follows improvement of blood
glucose control ?steal phenomenon
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Acute diffuse painful neuropathy Not related to duration of diabetes or
complications Association with marked weight loss severe burning/shooting pain, “electric
shocks”, allodynia Resolve spontaneously, usually with weight
gain, 6-8 months. Some 2 years. Does not relapse Signs may be lacking and dissociated from
symptoms
Pressure Palsies
↑ susceptibility to pressure damage
Limited joint mobility (soft tissue)
Carpal tunnel Ulnar nerve Lateral popliteal nerve
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DiagnosisAnnual review Enquire annually for:· Painful neuropathy· Loss of sensation· Erectile impotence Note duration of DM, treatment,
complications & weight Ask about other manifestations of
autonomic neuropathy if:· Other complications are present· Anaesthesia is contemplated· Blood glucose control is erratic
DiagnosisExamine: For evidence of peripheral neuropathy
annually LT
OR if new symptoms Vibration LT ?Thermal thresholds ?Pain For postural hypotension if symptoms
of autonomic neuropathy
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Examination-ANS
Ewing’s batteryAbnormal results common Valsalva-expiration for 15 secs against 40
mmHg. Rest 1 min then repeatx2. Avoid in proliferative retinopathy. RR max : RR min>1.21 =Normal, <1.20 = abnormal.
HR increase on standing RR 30:15 ratio > 1.04 HR↑ at max overshoot or 15 seconds ≥ 15bpm
(abnormal if<12)
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Ewing’s battery
HR variation during deep breathing (6 breaths per minute) Max-min > 15bpm (<10 is abnormal)
Postural BP-2 mins after standing Fall< 10mmHg normal >30 mmHg abnormal
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Diagnosis
Consider differential diagnoses HSMN Ethanol B12/folate Malignancy Renal failure Drugs AI disease Cord problems Leprosy
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Prevention
Control DCCT (1995)
Tight control-3% neuropathy at 5 years Conventional-10%
UKPDS (1998) Tight control (HbA1c 7%)-31.2% neuropathy
at 15 years Conventional (HbA1c 7.9%)-51.7% P=0.005 No protective effect seen for BP control
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Prevention
Aldose reductase inhibitors Gamma Linoleic Acid Vasodilators-ACE? AGE inhibitors Antioxidants NGFs ? Smoking cessation, ? BP reduction
Treatment-Painful neuropathyGeneral Measures
Improve glycaemic controlExclude or treat other contributory factors•Alcohol excess•Vitamin B12 deficiency/Folate•UraemiaSimple analgesia-NSAID/ParacetamolExplanation, empathy and reassurance
Choose drugs according to dominant symptoms
Burning pain
Tricyclics
Anticonvulsants
Duloxetine
Lancinating pain
Tricyclics
Anticonvulsants
Duloxetine
Other symptomsAllodynia•Plastic film•Leg cradle at nightRestless legs•RopinirolePainful Cramps•Quinine sulphate
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Treatment -ANS
Postural hypotension Fludrocortisone NSAIDs Compression stockings Elevate the head of the bed
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Treatment -ANS
Bladder Manual SP pressure ISC ? Anticholinesterase Cyclical antibiotics if recurrent infections
Sweating ?clonidine
Erectile dysfunction
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Treatment -ANS
Gastroparesis Improve glycaemic control Prokinetic drugs
Metoclopramide, domperidone, cisapride, erythromycin (250 mg tds) Octreotide? If severe→admit for IV fluids, IV drugs ± NG tube ± IV/jejunal
feedingDiarrhoea Codeine/loperamide/diphenoxylate Clonidine or octreotide Treat bacterial overgrowth (oxytet/erythromycin) if
suspected/present