Woman holding foot in pain

What is Painful Diabetic Neuropathy (PDN)?

Painful diabetic neuropathy is nerve damage that results from diabetes. The high blood sugar that frequently appears as a result of diabetes can cause permanent injury to nerves throughout your body, which causes the intense pain. PDN presents as a burning, excruciating, stabbing or intractable type of pain, or presents with tingling or numbness. Nerves in the legs and feet are most often damaged with this condition. The symptoms are often painful and debilitating. Diabetic neuropathy is a serious complication from diabetes and can affect up to 50% of people with diabetes. 

As a result of the nerves affected, painful diabetic neuropathy can produce pain and numbness in your legs and feet and lead to issues with your digestive system, urinary tract, heart, and blood vessels. 

The American Diabetes Association recommends that screening for diabetic neuropathy begin immediately after someone is diagnosed with type 2 diabetes, and five years after diagnosis for someone with type 1 diabetes. After that, screening is recommended annually.

Causes: 

There are four distinct types of diabetic neuropathy: peripheral neuropathy, autonomic neuropathy, proximal neuropathy (diabetic polyradiculopathy), and mononeuropathy (focal neuropathy). The exact cause of each type of neuropathy is unknown. 

Researchers think that, over time, uncontrolled high blood sugar damages nerves and interferes with their ability to send signals, leading to diabetic neuropathy. High blood sugar also weakens the walls of the small blood vessels (capillaries) that supply the nerves with oxygen and nutrients.

Symptoms: 

According to Mayo Clinic, since there are four main types of diabetic neuropathy, symptoms depend on the type of diabetic neuropathy someone has and its degree of severity. Symptoms typically have a gradual onset, and many don’t notice they have a problem until they have experienced considerable nerve damage. 

Peripheral neuropathy

This type of neuropathy may also be called distal symmetric peripheral neuropathy. It’s the most common type of diabetic neuropathy. It affects the feet and legs first, followed by the hands and arms. Signs and symptoms of peripheral neuropathy are often worse at night, and may include:

  • Numbness or reduced ability to feel pain or temperature changes
  • Tingling or burning sensation
  • Sharp pains or cramps
  • Increased sensitivity to touch — for some people, even a bedsheet’s weight can be painful
  • Serious foot problems, such as ulcers, infections, and bone and joint pain

Autonomic neuropathy

The autonomic nervous system controls your heart, bladder, stomach, intestines, sex organs and eyes. Diabetes can affect nerves in any of these areas, possibly causing:

  • A lack of awareness that blood sugar levels are low (hypoglycemia unawareness)
  • Bladder or bowel problems
  • Slow stomach emptying (gastroparesis), causing nausea, vomiting and loss of appetite
  • Changes in the way your eyes adjust from light to dark
  • Decreased sexual response

Proximal neuropathy (diabetic polyradiculopathy)

This type of neuropathy — also called diabetic amyotrophy — often affects nerves in the thighs, hips, buttocks or legs. It can also affect the abdominal and chest area. Symptoms are usually on one side of the body, but may spread to the other side. You may have:

  • Severe pain in a hip, thigh, or buttock
  • Eventual weak and shrinking thigh muscles
  • Difficulty rising from a sitting position
  • Severe stomach pain

Mononeuropathy (focal neuropathy)

There are two types of mononeuropathy — cranial and peripheral. Mononeuropathy refers to damage to a specific nerve. Mononeuropathy may also lead to:

  • Difficulty focusing or double vision
  • Aching behind one eye
  • Paralysis on one side of your face (Bell’s palsy)
  • Numbness or tingling in your hand or fingers, except your pinkie (little finger)
  • Weakness in your hand that may cause you to drop things

Treatment: 

Since diabetic neuropathy doesn’t have a known cure, the goals of treatment are to slow the progression of the disease, relieve pain, and manage complications/restore function. 

To Slow Disease Progression: 

  1. To slow the progression of the disease, consistent management of blood pressure levels within a normal range will help. Blood sugar levels might need to be set on an individual basis. The National Diabetes Association recommends between 80 and 130 mg/dL, which is 4.4 and 7.2 millimoles per liter (mmol/L) before meals and less than 180 mg/dL (10.0 mmol/L) two hours after meals. 
  2. Mayo Clinic encourages slightly lower blood sugar levels for most younger people with diabetes, and slightly higher levels for older people who may be more at risk of low blood sugar complications. Mayo Clinic generally recommends the following target blood sugar levels before meals: between 80 and 120 mg/dL (4.4 and 6.7 mmol/L) for people age 59 and younger who have no other medical conditions and between 100 and 140 mg/dL (5.6 and 7.8 mmol/L) for people age 60 and older, or for those who have other medical conditions, including heart, lung or kidney disease

Pain Relief: 

Prescription drugs represent another possible therapy for diabetes-related nerve pain. Potential options for pain relieving prescription medication are: 

Anti-seizure drugs: 

The American Diabetes Association recommends pregabalin (Lyrica) and Gabapentin (Gralise, Neurontin) as options. Side effects can include drowsiness, dizziness, and swelling. 

Antidepressants: 

Antidepressants can alleviate nerve pain, even if you aren’t depressed. Tricyclic antidepressants can help with mild to moderate nerve pain. Amitriptyline, desipramine (Norpramin) and imipramine (Tofranil) are all in this category of drug. Side effects can include dry mouth and drowsiness.

Serotonin and norepinephrine reuptake inhibitors (SNRIs) are another class of antidepressant that may help with nerve pain and have fewer potential side effects. The American Diabetes Association recommends duloxetine (Cymbalta) as a first treatment. Another that may be used is venlafaxine (Effexor XR). Possible side effects include nausea, sleepiness, dizziness, decreased appetite and constipation.

Physicians may combine an antidepressant drug with an anti-seizure drug. These drugs can also be used with pain-relieving medication, including acetaminophen (Tylenol) or ibuprofen (Advil or Motrin IB) or a skin patch with lidocaine (a numbing substance).

HFX™ Spinal Cord Stimulation (SCS): 

It’s the only spinal cord stimulation system approved by the FDA to manage pain associated with diabetic neuropathy. 

The HFX™ Solution treatment system involves a minimally-invasive implant procedure, allowing the patient to go home the same day. The spinal cord stimulation device then delivers mild electrical pulses to the nerves, interrupting the transmission of pain signals to the brain, which reduces pain. 

Managing Complications and Restoring Function: 

The treatment a patient requires will depend on the neuropathy-related complication a person has. 

  • Urinary tract problems. Some drugs affect bladder function, so your doctor may recommend stopping or changing medications. A strict urination schedule or urinating every few hours while applying gentle pressure to the bladder area can help some bladder problems. Other methods, including self-catheterization, may be needed to remove urine from a nerve-damaged bladder.
  • Digestive problems. To relieve mild signs and symptoms of gastroparesis — indigestion, belching, nausea or vomiting — doctors suggest eating smaller, more-frequent meals. Diet changes and medications may help relieve gastroparesis, diarrhea, constipation and nausea.
  • Low blood pressure on standing (orthostatic hypotension). Treatment starts with simple lifestyle changes, such as avoiding alcohol, drinking plenty of water, and changing positions such as sitting or standing slowly. Your doctor may also recommend compression support for your abdomen. Several medications, either alone or together, may be used to treat orthostatic hypotension.
  • Sexual dysfunction. Medications taken by mouth or injection may improve sexual function in some men, but they aren’t safe and effective for everyone. Mechanical vacuum devices may increase blood flow to the penis. Women may find relief with vaginal lubricants.

If you have any more questions, the pain specialist experts at Alliance Spine and Pain are here to help. Reach out to any of our pain specialists by clicking here or by giving us a call at 770-929-9033.