Peripheral neuropathy refers to the many conditions that involve damage to the peripheral nervous system, the vast communication network that sends signals between the central nervous system (the brain and spinal cord) and all other parts of the body. Peripheral nerves send many types of sensory information to the central nervous system (CNS), such as a message that the feet are cold. They also carry signals from the CNS to the rest of the body. Best known are the signals to the muscles that tell them to contract, which is how we move, but there are different types of signals that help control everything from our heart and blood vessels, digestion, urination, sexual function, to our bones and immune system. The peripheral nerves are like the cables that connect the different parts of a computer or connect the Internet. When they malfunction, complex functions can grind to a halt.

Nerve signaling in neuropathy is disrupted in three ways:

  • loss of signals normally sent (like a broken wire)
  • inappropriate signaling when there shouldn’t be any (like static on a telephone line)
  • errors that distort the messages being sent (like a wavy television picture)
  • Symptoms

    Symptoms often start gradually and then get worse. They may include

    • Numbness
    • Pain
    • Burning or tingling
    • Muscle weakness
    • Sensitivity to touch
  • Treatment

    Treatments depend entirely on the type of nerve damage, symptoms, and location. Your doctor will explain how nerve damage is causing specific symptoms and how to minimize and manage them. With proper education, some people may be able to reduce their medication dose or manage their neuropathy without medications. Definitive treatment can permit functional recovery over time, as long as the nerve cell itself has not died.

    Medication

    Medications recommended for chronic neuropathic pain are also used for other medical conditions. Among the most effective are a class of drugs first marketed to treat depression. Nortriptyline and newer serotonin-norepinephrine reuptake inhibitors such as duloxetine hydrochloride modulate pain by increasing the brain’s ability to inhibit

    incoming pain signals. Another class of medications that quiets nerve cell electrical signaling is also used for epilepsy. Common drugs include gabapentin, pregabalin, and less often topiramate and lamotrigine. Carbamazepine and oxcarbazepine are particularly effective for trigeminal neuralgia, a focal neuropathy of the face. Local anesthetics and related drugs that block nerve conduction may help when other medications are ineffective or poorly tolerated.

    Narcotics (opioids) can be used for pain that doesn’t respond to other pain-control medications and if disease-improving treatments aren’t fully effective. Because pain relievers that contain opioids can lead to dependence and addiction, their use must be closely monitored by a physician. One of the newest drugs approved for treating diabetic neuropathy is tapentadol, which has both opioid activity and norepinephrine-reuptake inhibition activity of an antidepressant.

    Transcutaneous electrical nerve stimulation

    (TENS) is a noninvasive intervention used for pain relief in a range of conditions. TENS involves attaching electrodes to the skin at the site of pain or near associated nerves and then administering a gentle electrical current. Although data from controlled clinical trials are not available to broadly establish its efficacy for peripheral neuropathies, in some studies TENS has been shown to improve neuropathic symptoms associated with diabetes.