Diabetic Neuropathy

1
Diabetic Neuropathy
2
Diabetic Neuropathy

• About 60-70 of people with diabetes have mild to
  severe forms of nervous system damage, including
  
• Impaired sensation or pain in the feet or hands
• Slowed digestion of food in the stomach
• Carpal tunnel syndrome
• Other nerve problems
• More than 60 of nontraumatic lower-limb
  amputations in the United States occur among
  people with diabetes.

3
Risk Factors

• Glucose control
• Duration of diabetes
• Damage to blood vessels
• Mechanical injury to nerves
• Autoimmune factors
• Genetic susceptibility
• Lifestyle factors
• Smoking
• Diet

4
Pathogenesis of Diabetic Neuropathy

• Metabolic factors
• High blood glucose
• Advanced glycation end products
• Sorbitol
• Abnormal blood fat levels
• Ischemia
• Nerve fiber repair mechanisms

5
Diagnostic Tests

• Assess symptoms - muscle weakness, muscle cramps,
  prickling, numbness or pain, vomiting, diarrhea,
  poor bladder control and sexual dysfunction
• Comprehensive foot exam
• Skin sensation and skin integrity
• Quantitative Sensory Testing (QST)
• X-ray
• Nerve conduction studies
• Electromyographic examination (EMG)
• Ultrasound

6
Classification of Diabetic Neuropathy

• Symmetric polyneuropathy
• Autonomic neuropathy
• Polyradiculopathy
• Mononeuropathy

7
Symmetric Polyneuropathy

• Most common form of diabetic neuropathy
• Affects distal lower extremities and hands
  (stocking-glove sensory loss)
• Symptoms/Signs
• Pain
• Paresthesia/dysesthesia
• Loss of vibratory sensation

8
Complications of Polyneuropathy

• Ulcers
• Charcot arthropathy
• Dislocation and stress fractures
• Amputation - Risk factors include
• Peripheral neuropathy with loss of protective
  sensation
• Altered biomechanics (with neuropathy)
• Evidence of increased pressure (callus)
• Peripheral vascular disease
• History of ulcers or amputation
• Severe nail pathology

9
Treatment of Symmetric Polyneuropathy

• Glucose control
• Pain control
• Tricyclic antidepressants
• Topical creams
• Anticonvulsants
• Foot care

10
Essentials of Foot Care

• Examination
• Annually for all patients
• Patients with neuropathy - visual inspection of
  feet at every visit with a health care
  professional
• Advise patients to
• Use lotion to prevent dryness and cracking
• File calluses with a pumice stone
• Cut toenails weekly or as needed
• Always wear socks and well-fitting shoes
• Notify their health care provider immediately if
  any foot problems occur

11
Autonomic neuropathy

• Affects the autonomic nerves controlling internal
  organs
• Peripheral
• Genitourinary
• Gastrointestinal
• Cardiovascular
• Is classified as clinical or subclinical based on
  the presence or absence of symptoms

12
Peripheral Autonomic Dysfunction

• Contributes to the following symptoms/signs
• Neuropathic arthropathy (Charcot foot)
• Aching, pulsation, tightness, cramping, dry skin,
  pruritus, edema, sweating abnormalities
• Weakening of the bones in the foot leading to
  fractures
• Testing
• Direct microelectrode recording of
  postglanglionic C fibers
• Galvanic skin responses
• Measurement of vascular responses

13
Peripheral Autonomic Dysfunction, cont.

• Treatment
• Foot care/elevate feet when sitting
• Eliminate aggravating drugs
• Reduce edema
• midodrine
• diuretics
• Support stockings
• Screen for CVD

14
Genitourinary Autonomic Neuropathy
15
Gastrointestinal Autonomic Neuropathy

• Symptoms/Signs
• Gastroparesis resulting in anorexia, nausea,
  vomiting, and early satiety
• Diabetic enteropathy resulting in diarrhea and
  constipation
• Treatment
• Other causes of gastroparesis or enteropathy
  should first be ruled out
• Gastroparesis - Small, frequent meals,
  metoclopramide, erythromycin
• Enteropathy - loperamide, antibiotics, stool
  softeners or dietary fiber

16
Cardiovascular Autonomic Neuropathy

• Symptoms/Signs
• Exercise intolerance
• Postural hypotension
• Treatment
• Discontinue aggravating drugs
• Change posture (make postural changes slowly,
  elevate bed)
• Increase plasma volume

17
Polyradiculopathy

• Lumbar polyradiculopathy (diabetic amyotrophy)
• Thigh pain followed by muscle weakness and
  atrophy
• Thoracic polyradiculopathy
• Severe pain on one or both sides of the abdomen,
  possibly in a band-like pattern
• Diabetic neuropathic cachexia
• Polyradiculopathy peripheral neuropathy
• Associated with weight loss and depression

18
Polyradiculopathy, cont.

• Polyradiculopathies are diagnosed by
  electromyographic (EMG) studies
• Treatment
• Foot care
• Glucose control
• Pain control

19
Mononeuropathy

• Peripheral mononeuropathy
• Single nerve damage due to compression or
  ischemia
• Occurs in wrist (carpal tunnel syndrome), elbow,
  or foot (unilateral foot drop)
• Symptoms/Signs
• numbness
• edema
• pain
• prickling

20
Mononeuropathy, cont.

• Cranial mononeuropathy
• Affects the 12 pairs of nerves that are connected
  with the brain and control sight, eye movement,
  hearing, and taste
• Symptoms/Signs
• unilateral pain near the affected eye
• paralysis of the eye muscle
• double vision
• Mononeuropathy multiplex

21
Mononeuropathy, cont.

• Treatment
• Foot care
• Glucose control
• Pain control

22
Other Treatment Options

• Aldose reductase inhibitors
• ACE inhibitors
• Weight control
• Exercise

23
References

• American Diabetes Association Preventive Foot
  Care in Diabetes
• (Position Statement). Diabetes Care 27 (Suppl.1)
  S63-S64, 2004
• Feldman, EL Classification of diabetic
  neuropathy. In UpToDate.
• Wellesley, MA, UpToDate, 2003
• National Diabetes Information Clearinghouse.
  Diabetic Neuropathies
• The Nerve Damage of Diabetes. Bethesda, MD
  National Institute of
• Diabetes and Digestive and Kidney Diseases,
  National Institutes of
• Health (NIH), DHHS 2002
• National Diabetes Information Clearinghouse.
  Prevent Diabetes
• Problems Keep Your Feet and Skin Healthy.
  Bethesda, MD National
• Institute of Diabetes and Digestive and Kidney
  Diseases, National
• Institutes of Health (NIH), DHHS 2003

24
References, cont.

• Feldman, EL Pathogenesis and prevention of
  diabetic
• polyneuropathy. In UpToDate. Wellesley, MA,
  UpToDate, 2003.
• Feldman, EL, McCulloch, DK Treatment of diabetic
  neuropathy. In
• UpToDate. Wellesley, MA, UpToDate, 2003.
• Stevens, MJ Diabetic autonomic neuropathy. In
  UpToDate.
• Wellesley, MA, UpToDate, 2003.
• Feldman, EL Clinical manifestations and
  diagnosis of diabetic
• polyneuropathy. In UpToDate. Wellesley, MA,
  UpToDate, 2003.