What Is Peripheral Neuropathy?

June 29, 2019
Peripheral neuropathy is the poor functioning of the nerves that transmit sensations to the brain. It affects the patient's ability to feel things by touch. Read on to learn more!

The peripheral nervous system (PNS) is the nerve net outside of the central nervous system (consisting of the brain and spinal cord). Its main job is transmitting signals of physical sensations from the periphery to the brain. Peripheral neuropathy is when these nerves don’t work properly because they’re damaged.

PNS involves several different nerve types that have a specific function. Some of them are:

  • Sensory nerves that transmit sensations such as pain and touch.
  • Motor nerves responsible for controlling the muscles.
  • Autonomic nerves that regulate the body’s automatic functions, such as blood pressure and bladder functioning.

Peripheral neuropathy can affect one group of nerves or all three of them at the same time. In any case, when the patient suffers from peripheral neuropathy, normal nerve functioning is interrupted, so they may send pain signals randomly or not send them at all when something is actually harming the body.

This condition can result from an injury, a systemic disease, an infection, or a genetic disorder.

Neurons and nervous activity in peripheral neuropathy.

The Symptoms of Peripheral Neuropathy

The symptoms vary depending on the type of neuropathy.

Sensory Neuropathy

It may manifest with the following symptoms:

  • Numbness or tingling sensation.
  • Hypersensitivity and feeling needles or pins in some body areas.
  • More pain or inability to feel pain at all.
  • Inability to detect changes in temperature.
  • Poor postural stability and proprioception.
  • Burning or stinging pain that might get worse at night.

Sensory neuropathy can also cause foot ulcers, infection, and gangrene.

Motor Neuropathy

Motor neuropathy affects the muscles. Its symptoms are:

  • Muscle weakness, which results in instability and difficulty making small movements.
  • Atrophy.
  • Muscle seizures and cramps.
  • Muscle paralysis.

If autonomic nerves are also affected, the patient can suffer vegetative symptoms related to sweating, pain tolerance, bowel or bladder functioning, and blood pressure changes that may cause dizziness.

The Causes of Peripheral Neuropathy

Although many types of neuropathy are idiopathic (their cause is unknown), several other conditions may trigger it. In fact, diabetes is one of the most common causes of chronic peripheral neuropathy due to the fact that high blood sugar levels damage the nerves.

Other potential conditions and injuries that cause it are:

  • Chronic kidney disease. If the kidneys aren’t working properly, the resulting mineral and chemical compound balance can cause peripheral neuropathy.
  • Skeletal muscle injuries. Broken bones and tight casts can put pressure on the nerves and damage them.
  • Infections. Herpes zoster, HIV, Lyme disease, and other such infections can damage the nerves.
  • Guillain-Barre syndrome: which is a specific type of peripheral neuropathy triggered by a viral infection.
  • Autoimmune diseases, especially rheumatoid arthritis and systemic lupus erythematosus.
Foot nerves.

Here are other possible causes of peripheral neuropathy:

  • Excessive alcohol consumption
  • Specific medication (such as chemotherapeutic and HIV drugs).
  • Certain vitamin deficiency, such as B12, B1, B6, and E.
  • Consumption of toxic and poisonous products, such as insecticides and solvents.
  • Some types of cancer, including lymphoma and multiple myeloma.
  • Chronic liver disease.

Also, small vessel disease can reduce the amount of blood that reaches the nerves, which causes damage in the nervous tissue. Neuromas, which are benign tumors that affect the nervous tissue, can also cause neuropathic pain.

Treatment for Peripheral Neuropathy

Treatment for peripheral neuropathy depends on the symptoms and the underlying cause. Only some of these causes are treatable. For example, in the case of diabetes, maintaining blood sugar levels can be of great help, as well as not smoking nor drinking alcohol.

Medication for neuropathic pain involves the use of “neuropathic pain agents” because analgesics are often ineffective.

Other symptoms associated with peripheral neuropathy can require individual treatment. For example, treating muscle weakness can involve physiotherapy and mobility aid.

Many people also benefit from transcutaneous electrical nerve stimulation (TENS). In this non-invasive and medication-free therapy, electrodes placed on the skin transmit small amounts of electricity. The aim of this treatment is to avoid the nerves from transmitting pain signals to the brain due to a nervous flow interruption caused by the electrical discharge.

On the other hand, it’s worth noting that many patients have improved with alternative approaches such as chiropractic, acupuncture, and massage. Also, meditation and yoga tend to be very useful to relieve the symptoms. Finally, moderate and regular exercise can also help reduce the discomfort of this painful condition.