Diabetic Neuropathy

Diabetic neuropathy is a nerve disease or nerve damage that is caused by diabetes mellitus. About half of all people with diabetes mellitus have some form of nerve damage. Nerve damage is more common in those who have had diabetes mellitus for many years and who generally have not had good control of their blood sugar (glucose) level. Diabetic neuropathy is a common complication of diabetes mellitus. There are three more common types of diabetic neuropathy and a fourth type that is less common and less understood:

  • Peripheral neuropathy—This is the most common type of diabetic neuropathy. It causes damage to the nerves of the feet and legs first and then eventually the hands and arms. The damage affects the ability to sense touch.

  • Autonomic neuropathy—This type causes damage to the autonomic nervous system, which controls the following functions:

  • Heartbeat.

  • Body temperature.

  • Blood pressure.

  • Urination.

  • Digestion.

  • Sweating.

  • Sexual function.

  • Focal neuropathy—Focal neuropathy can be painful and unpredictable and occurs most often in older adults with diabetes mellitus. It involves a specific nerve or one area and often comes on suddenly. It usually does not cause long-term problems.

  • Radiculoplexus neuropathy— Sometimes called lumbosacral radiculoplexus neuropathy, radiculoplexus neuropathy affects the nerves of the thighs, hips, buttocks, or legs. It is more common in people with type 2 diabetes mellitus and in older men. It is characterized by debilitating pain, weakness, and atrophy, usually in the thigh muscles.

CAUSES

The cause of peripheral, autonomic, and focal neuropathies is diabetes mellitus that is uncontrolled and high glucose levels. The cause of radiculoplexus neuropathy is unknown. However, it is thought to be caused by inflammation related to uncontrolled glucose levels.

SIGNS AND SYMPTOMS

Peripheral Neuropathy

Peripheral neuropathy develops slowly over time. When the nerves of the feet and legs no longer work there may be:

  • Burning, stabbing, or aching pain in the legs or feet.

  • Inability to feel pressure or pain in your feet. This can lead to:

  • Thick calluses over pressure areas.

  • Pressure sores.

  • Ulcers.

  • Foot deformities.

  • Reduced ability to feel temperature changes.

  • Muscle weakness.

Autonomic Neuropathy

The symptoms of autonomic neuropathy vary depending on which nerves are affected. Symptoms may include:

  • Problems with digestion, such as:

  • Feeling sick to your stomach (nausea).

  • Vomiting.

  • Bloating.

  • Constipation.

  • Diarrhea.

  • Abdominal pain.

  • Difficulty with urination. This occurs if you lose your ability to sense when your bladder is full. Problems include:

  • Urine leakage (incontinence).

  • Inability to empty your bladder completely (retention).

  • Rapid or irregular heartbeat (palpitations).

  • Blood pressure drops when you stand up (orthostatic hypotension). When you stand up you may feel:

  • Dizzy.

  • Weak.

  • Faint.

  • In men, inability to attain and maintain an erection.

  • In women, vaginal dryness and problems with decreased sexual desire and arousal.

  • Problems with body temperature regulation.

  • Increased or decreased sweating.

Focal Neuropathy

  • Abnormal eye movements or abnormal alignment of both eyes.

  • Weakness in the wrist.

  • Foot drop. This results in an inability to lift the foot properly and abnormal walking or foot movement.

  • Paralysis on one side of your face (Bell palsy).

  • Chest or abdominal pain.

Radiculoplexus Neuropathy

  • Sudden, severe pain in your hip, thigh, or buttocks.

  • Weakness and wasting of thigh muscles.

  • Difficulty rising from a seated position.

  • Abdominal swelling.

  • Unexplained weight loss (usually more than 10 lb [4.5 kg]).

DIAGNOSIS

Peripheral Neuropathy

Your senses may be tested. Sensory function testing can be done with:

  • A light touch using a monofilament.

  • A vibration with tuning fork.

  • A sharp sensation with a pin prick

Other tests that can help diagnose neuropathy are:

  • Nerve conduction velocity. This test checks the transmission of an electrical current through a nerve.

  • Electromyography. This shows how muscles respond to electrical signals transmitted by nearby nerves.

  • Quantitative sensory testing. This is used to assess how your nerves respond to vibrations and changes in temperature.

Autonomic Neuropathy

Diagnosis is often based on reported symptoms. Tell your health care provider if you experience:

  • Dizziness.  

  • Constipation.  

  • Diarrhea.  

  • Inappropriate urination or inability to urinate.  

  • Inability to get or maintain an erection.  

Tests that may be done include:

  • Electrocardiography or Holter monitor. These are tests that can help show problems with the heart rate or heart rhythm.  

  • An X-ray exam may be done.

Focal Neuropathy

Diagnosis is made based on your symptoms and what your health care provider finds during your exam. Other tests may be done. They may include:

  • Nerve conduction velocities. This checks the transmission of electrical current through a nerve.

  • Electromyography. This shows how muscles respond to electrical signals transmitted by nearby nerves.

  • Quantitative sensory testing. This test is used to assess how your nerves respond to vibration and changes in temperature.

Radiculoplexus Neuropathy

  • Often the first thing is to eliminate any other issue or problems that might be the cause, as there is no stick test for diagnosis.

  • X-ray exam of your spine and lumbar region.

  • Spinal tap to rule out cancer.

  • MRI to rule out other lesions.

TREATMENT

Once nerve damage occurs it cannot be reversed. The goal of treatment is to keep the disease or nerve damage from getting worse and affecting more nerve fibers. Controlling your blood glucose level is the key. Most people with radiculoplexus neuropathy see at least a partial improvement over time. You will need to keep your blood glucose and HbA1c levels in the target range determined by your health care provider. Things that help control blood glucose levels include:

  • Blood glucose monitoring.  

  • Meal planning.  

  • Physical activity.  

  • Diabetes medicine.  

Over time, maintaining lower blood glucose levels helps lessen symptoms. Sometimes, prescription pain medicine is needed.

HOME CARE INSTRUCTIONS:

  • Do not smoke.

  • Keep your blood glucose level in the range that you and your health care provider have determined acceptable for you.

  • Keep your blood pressure level in the range that you and your health care provider have determined acceptable for you.

  • Eat a well-balanced diet.

  • Be active every day.

  • Check your feet every day.

SEEK MEDICAL CARE IF:

  • You have burning, stabbing, or aching pain in the legs or feet.

  • You are unable to feel pressure or pain in your feet.

  • You develop problems with digestion such as:

  • Nausea.

  • Vomiting.

  • Bloating.

  • Constipation.

  • Diarrhea.

  • Abdominal pain.

  • You have difficulty with urination, such as:

  • Incontinence.

  • Retention.

  • You have palpitations.

  • You develop orthostatic hypotension. When you stand up you may feel:

  • Dizzy.

  • Weak.

  • Faint.

  • You cannot attain and maintain an erection (in men).

  • You have vaginal dryness and problems with decreased sexual desire and arousal (in women).

  • You have severe pain in your thighs, legs, or buttocks.

  • You have unexplained weight loss.