Brief Overview

One of the most common complications of diabetes that we see effecting our patients is peripheral polyneuropathy. Neuropathy is a disease state of the peripheral nervous system which may cause a burning pain associated with tingling, weakness and loss of sensation. The peripheral nervous system is the part of the nervous system that carries signals from the brain and spinal cord to the muscles and organs. This system also carries signals from the sensory organs within the body back to the spinal cord and brain for processing. Not everyone with peripheral neuropathy has pain and although many cases are caused by diabetes there are other conditions that can cause neuropathy such as exposure to toxins (i.e. certain chemotherapy drugs), metabolic conditions, infections and trauma among others.

Regardless of the cause of the neuropathy, the underlying problem is that of nerve damage which often initially causes symptoms in the hands and feet. Over time the symptoms will progress to involve areas closer to the core of the body.

Symptoms

It is important to note that the symptoms are gradual in onset and usually involve a feeling of numbness or tingling that initially effects the hands and feet and eventually begins to involve areas within the arms and legs. You should inquire with your physician if you experience any of the following:

  • Burning pain, numbness, tingling or sensitivity to touch (especially over the shin areas and feet).
  • Lack of coordination causing walking difficulty and potentially falls with injury
  • Muscle weakness
  • Heat intolerance
  • Excessive sweating or not being able to sweat
  • Bowel, bladder or digestive difficulty or chest pain
  • Changes in blood pressure, causing dizziness or lightheadedness

Some of these symptoms including the heat intolerance, bowel, bladder and circulatory involvement are a result of the neuropathy affecting the autonomic nervous system which controls the bodily organs. Interestingly, the walking difficulty is due to the loss of nerve function blocking the conveyance of positional sensory information from the joints in the ankles and feet. Other joints can become involved later in the course. Because your body is unable to transmit this information to the brain it becomes more difficult to coordinate your leg movements when walking, especially when combined with muscle weakness. People with this problem tend to fall more often which can result in serious injures like hip fractures and traumatic brain injury. The lack of sensation and increased risk of infection caused by diabetes can result in soft tissue infections especially involving the toes and feet which may progress to gangrene and the need for toe or limb amputation. The symptoms of neuropathy may precede the diagnosis of diabetes by years so be sure to bring these symptoms to your physician’s attention. 

Diagnosis/ Treatment

Your physician may diagnose you with peripheral neuropathy based on your reported symptoms combined with a quick bedside monofilament test. This test involves a filament that is touched to various points on the body to determine if there is loss of sensation.

Further evaluation can involve blood tests, imaging or nerve biopsy depending on the likelihood that there may be causes other than diabetes to explain the neuropathy.

You may also undergo a more extensive evaluation called a nerve conduction study with electromyography (EMG) to thoroughly evaluate several nerves in the upper and low body to determine how well they are functioning. This can help establish how many nerves are involved and whether there are sensory and/or motor nerves involved.

Treating neuropathy usually involves managing the pain symptoms. If the cause is attributed to conditions other than diabetes it could potentially be reversed (i.e. B vitamin deficiencies).

Treating the pain may include prescriptions for medications such as; Gabapentin, Pregabalin (Lyrica), Cymbalta, Amitriptyline, Nortriptyline or Doxepin.

These medications have various mechanisms for addressing the nerve pain. Medication selection will be based on your physician’s evaluation of what will work best for you based on your own unique circumstances including avoiding potential interactions with other medications that you may be using.

Opiates should be avoided due to the development of dependence and associated medication side effects and potential complications.

If the cause of your neuropathy is related to certain immune system mediated conditions you may benefit from other treatments so be sure to talk to your physician about the specific cause of your neuropathy.

If you develop muscle weakness and walking difficulty a physical therapist can work on strengthening your muscles and evaluate your gait to determine the potential for improvement and develop and exercise plan. The gait interventions may involve you using a walker or cane for improved stability. Bracing options should also be considered carefully depending on the potential for you to benefit functionally while also considering the need to avoid skin complications.

Overall, with diligent attention to your skin integrity and proactively addressing your ability to function safely you may be able to avoid many of the complications associated with peripheral neuropathy.