Summary: What is Neuropathy?
The nervous system can be broadly divided into the central nervous system and the peripheral nervous system. The central nervous system encompasses the brain and spinal cord. The peripheral nervous system is the network of nerves outside the brain and spinal cord. It is composed of:
- Sensory nerves that send sensory information from your eyes, ears, tongue, nose, and skin to the brain;
- Motor nerves that carry messages from the brain to the muscles to create movement
- Autonomic nerves that are part of your body’s “autopilot” system (i.e. those that control breathing, digestion, etc.).
Neuropathy, also known as peripheral neuropathy, occurs when there is damage that alters or disrupts the flow of signals through nerves. The term, peripheral neuropathy, indicates that the nerves involved are a part of the peripheral nervous system. As a result of how expansive and integrated the peripheral nervous system is, peripheral neuropathy has a wide range of causes, treatments, and complications.
A peripheral neuropathy is different than nerve damage in that it usually affects many nerves as opposed to a nerve or nerves in a local area due to “damage” from pinching, injury, or destruction of the nerve.
Clinical Presentation
Patients will present with a tingling sensation, numbness, and/or weakness in the areas supplied by the affected nerves. For patients with a peripheral neuropathy affecting the lower extremities, this will often lead to a loss of sensation over the feet in a stocking distribution as the nerves furthest away from the spinal cord are often affected first. Patients may also experience sharp or burning pain in these areas. Symptoms may have a rapid onset or develop slowly over time, depending on the underlying cause. Patients with a peripheral neuropathy are at considerable risk for developing an ulcer on their feet as they often will not adequately sense increased pressure or loading on the skin. These ulcers can lead to bacteria entering from the outside world with a resulting serious infection. There are several risk factors and potential causes of peripheral neuropathy. The patient’s history may reveal one or more of the following:
Risk Factors and Causes
- Diabetes: Diabetes is another common cause of peripheral neuropathy. Diabetic neuropathy occurs when high levels of sugar in the blood cause nerve damage.
- Excess chronic alcohol intake
- Vitamin B12 deficiency
- Infections such as leprosy and syphilis
- Autoimmune disorders: a large family of disorders, primarily caused by the body’s immune system attacking itself. This “self-sabotage” can lead to damaged or dysfunctional nerves. Some autoimmune disorders include the following:
- Lupus
- Sjogren’s syndrome
- Guillain-Barre syndrome
- Chronic inflammatory demyelinating polyneuropathy.
- Kidney failure: the kidney filters the blood and helps the body get rid of certain toxins. Therefore, kidney disorders can increase the risk of neuropathy.
Treatment
Treatment of neuropathy is variable and depends on the location, underlying cause, and severity of symptoms. Treatment is focused on slowing the progression of the peripheral neuropathy and treating symptoms that the neuropathy creates.
- Diabetic neuropathy can be treated by appropriately managing blood sugar levels.
- Autoimmune disorders and infections that cause an autoimmune response can be treated by using immunosuppressive agents.
- Pain relievers may be used to treat pain from the nerve damage. Common pain-relieving medications include serotonin-norepinephrine reuptake inhibitors, local anesthetics, and opioids.
- Patient’s with an established peripheral neuropathy should prophylactically check the soles of their feet each day to ensure that if an ulcer develops it is identified early.
- If an ulceration does develop on the foot it is often treated with debridement (removal of dead tissue) and offloading with a cast or boot until it has healed.
Edited July 5th, 2021