Types of Neuropathy

Neuropathy refers to a set of nerve disorders that may or may not have symptoms. Most diabetics experience some form of neuropathy in their lifetime. Most people with diabetic neuropathy have had diabetes for at least 25 years, but it can occassionally develop even before you are officially diagnosed with diabetes. The most common type of neuropathy is the peripheral neuropathy category, so named because it’s the peripheral nerves that are affected. This is a condition that approximately 60% to 75% of all diabetics experience.

The Classification of Diabetic Neuropathy

There are several different types of common diabetic neuropathies. Each has its own symptoms, and each has its own negative effects upon the body. The types of neuropathy include the following:[1]

  • Distal symmetric sensorimotor polyneuropathy
  • Autonomic neuropathy
  • Cranial neuropathy
  • Limb neuropathy
  • Trunk mononeuropathy
  • Mononeuropathy multiplex
  • Asymmetric lower limb motor neuropathy (amyotrophy)

Each type of neuropathy will fall within one of the 4 main categories of neuropathy which are: 1) peripheral neuropathy affecting the feet and toes, legs, and arms and hands; 2) autonomic neuropathy affecting automatic biological processes like blood pressure; 3) proximal neuropathy affecting the area between the waist and knees; and 4) focal neuropathy affecting a group of nerves or one nerve anywhere in the body.

Distal Symmetric Sensorimotor Polyneuropathy (DSSP)

The various forms of diabetic peripheral neuropathy have common characteristics. The most common aspect relates to the word “peripheral.” The sensations seem to start at the far ends of the limbs like in the fingers or toes. The peripheral nerve sensors in the skin carry the sensation of touch and being touched to the CNS. The process involves a mixture of chemistry and electricity and takes a measurable length of time.

There are 3 major nerves in the hand. Each conveys the sensation of touch to a separate part of the hand. However, in Distal Symmetric Sensorimotor Polyneuropathy (DSSP) the patient reports a tingling feeling not in one area but spread throughout the hand. This is called “glove anesthesia” when it appears in the hand.

When the neuropathy radiates from the toes or feet it is called “stocking anesthesia”. This overall numbness indicates a polyneuropathy. In other words, not one but several nerves are involved.

Other feelings may include:

  • Prickly pains
  • A burning or stabbing sensation
  • A very high sensitivity of touch – even the sensation of a bed sheet can result in pain
  • An overall “pins-and-needles” feeling[2]

DSSP is the most common neuropathy experienced by diabetics.

Autonomic neuropathy[3]

Automatic neuropathy can affect the various nerves that govern automatic functions. These include control of your heart, lungs, intestines, stomach, sexual organs and bladder.[4]  When the autonomic nerves become damaged in diabetic neuropathy, the diabetic will experience obvious symptoms. For example, you may develop sudden hypotension (a fall in blood pressure) when getting up out of a chair because the nervous system is damaged and cannot keep the blood pressure coordinated to the movement. Standing up quickly can produce a feeling of dizziness or faintness. The heart beat may seem irregular or abnormal. Other symptoms a doctor might recognize indicate the particular nerves that are affected.

Cranial neuropathy

The cranial nerves are mainly related to the brain. Mononeuropathy, the involvement of a single nerve, is most commonly noted with the 3rd (oculomotor), 4th (trochlear), and the 6th (abducens) cranial nerves. All of these nerves lead to the eye. Cranial neuropathy may cause partial paralysis of the eye and/or the eyelid as well as severe pain.

Limb mononeuropathy

In a case of limb mononeuropathy only a single nerve in the arm or leg may be involved. The result is:

  • Loss of muscle power
  • Abnormal sensations
  • Radiating pain

This is frequently a form of entrapment neuropathy – the nerve is compressed as it passes under a fibrous band, for example the median nerve being compressed causing carpal tunnel syndrome. These are common with advancing age and may involve sensations involving the median nerve at the wrist, the ulnar nerve behind the elbow and the peroneal nerve at the knee. It is possible to relieve the symptoms through surgical decompression of the nerve. On the other hand, the individual may undergo spontaneous recovery.

Trunk mononeuropathy

Trunk neuropathy refers to a type of chest or abdominal pain. It is caused by the involvement of a peripheral nerve originating from the thoracic area of the spine. The nerve proceeds along the ribs to the front of the patient.

Asymmetric lower limb motor neuropathy – plexus neuropathy or amyotrophy

Diabetic amyotrophy refers to a different kind of nerve damage. The focal point is the plexus of nerve roots that collaborate, switch fibers and shape nerves. Symptoms of this type of neuropathy include:

  • Upper leg and back pain for a period of time
  • Weakness of the upper leg muscles

This characteristically occurs in individuals who do not properly manage their diabetes. The blood glucose levels are poorly controlled. The pain begins but then subsides when weakness occurs. The means of preventing future occurrences lies within the individual. He or she needs to exert excellent diabetic control.

Treatment of Painful Diabetic Neuropathy

The ideal treatment for diabetic neuropathy should be focused on averting or slowing the progressive loss of nerve function as well as improving symptoms. This should be accomplished with the least side effects possible. Historically, diabetic neuropathic pain has been treated with some of the older tricyclic antidepressants (amitriptyline or nortriptyline). The problem with using such medications, however, is the side effects. These include:

  • Weight gain
  • Constipation
  • Sleepiness

The more recent approach is to treat the symptoms with anticonvulsants including Duloxetine and Pregabalin. These medications usually allow good control of the pain with fewer side effects. Other methods of treatment considered and often used include:[5]

  • Opioid analgesics – a controversial treatment that should not be used for long term symptom control
  • Antiarrhythmics – not recommended for long term use e.g. Mexilitine

Other analgesic medications are also prescribed and include clonazepam and tramadol. Topical treatments such as capsaicin cream and topical nitrate are also possible. Alternative treatments include acupuncture and supplements such as ALA.

While the treatment options for peripheral diabetic neuropathy are limited, the best step is that taken by the patient. It cannot be stated strongly enough how important it is that the individual keep their glucose concentration within the limited range. The best way to prevent neuropathy from developing and progressing is to agressively control your diabetes and maintain normal glucose levels as advised by your doctor.

Conclusion

Neuropathy can be a very painful complication of diabetes. It is classified in several ways. Yet all types are the result of nerve damage. Talk to your doctor about what type of treatment you will require. Understand that this consequence is avoidable if you act responsibly and keep your diabetes under control.

References

[1] Levin, ME; and Pfeiffer, MA (editors) (2009). The Uncomplicated Guide to Diabetes Complications, 3rd ed. Alexandria, VA: ADA.

[2] Stanley, K (2009). 50 Things You Need To Know About Diabetes. Alexandria, VA: ADA.

[3] Masharani, U (2008). Diabetes DeMYSTiFieD. New York: McGraw Hill.

[4] American Diabetes Association (2009). Type 2 Diabetes. Your Healthy Living Guide. Alexandria, VA: ADA.

[5] Veves, A; Backonja, M; and Malik, RA (2008). “Painful Diabetic Neuropathy: Epidemiology, Natural History, Early Diagnosis, and Treatment Options.” Pain Medicine, 9 (6): 660–674.

This article was originally published July 12, 2012 and last revision and update of it was 9/10/2015.