Neuropathy

What is Peripheral Neuropathy?

When a person has peripheral neuropathy, essentially what they have is damage of the peripheral nervous system. There are two regions to the nervous system — Central and Peripheral. The Central system includes the brain and spinal cord, while the Peripheral system includes all the nerve roots and extremity nerves emanating from it.Examples of peripheral nerves include lumbar nerve roots, the median nerve, the shoulder's brachial plexus, the sciatic nerve, etc. It's a broad network, and all of these peripheral nerves transmit vital motor and sensory information throughout the body. They may tell your foot when to feel cold, or cause pain in your shoulder, or allow your biceps to flex. A peripheral neuropathy may interrupt some of these transmissions, or at a minimum distort them.

Symptoms from peripheral neuropathy emanate from this damage. Some individuals with peripheral neuropathy experience tingling, numbness, or pricking sensations, sensitivity to touch, or muscle weakness. More severe neuropathy symptoms may include burning pain, muscle wasting, paralysis, or gland dysfunction.

Types of Peripheral Neuropathy

There are 3 types of peripheral neuropathy:

1. Mononeuropathies = damage to only one nerve
2. Polyneuropathy = multiple nerves affecting all limbs
3. Mononeuritis multiplex = 2 or more nerves in separate areas of the body being affected in isolation.

Peripheral neuropathy is complicated in how it progresses, resolves, or plateaus. Diabetic neuropathy, which is a polyneuropathy, often affects one's feet first, travels up both legs, and then subsequently affects the fingers and hands moving up the arms. It is ascending nerve damage. Not everyone experiences the same pain areas or severity.

An example of a mononeuropathy is carpal tunnel syndrome, where the median nerve is a victim of compression in a person's wrist. It is where one nerve is affected, and it is well known that there are infinite levels of severity with a mononeuropathy. It may affect a person so severely that surgery becomes necessary, or it may simply be a nuisance from time to time.

Mononeuritis multiplex is a fairly complicated, painful condition involving at least 2 separate nerve areas. It is actually a group of disorders that is associated with disorders such as diabetes, rheumatoid arthritis, vasculitis, amyloidosis, Lyme disease, and potentially numerous other conditions. The incidence of mononeuritis multiplex in the US is actually unknown.

What causes peripheral neuropathy?

The most common cause of peripheral neuropathy is diabetes (by far). Sometimes the cause is completely unknown (idiopathic). Here are some other potential causes for neuropathy:

• Autoimmune disorders rheumatoid arthritis or lupus
• Chronic kidney disease
• Infections such as HIV and liver infections
• Low levels of vitamin B12 or other problems with your diet
• Poor blood flow to the legs
• Underactive thyroid gland
• Drug use such as heavy alcohol consumption
• Toxin exposure such as lead, mercury, and solvents may lead to peripheral neuropathy.
• Pharmaceutical drugs used to treat infections, cancer, seizures, or high blood pressure.

What are the symptoms of peripheral neuropathy?

This is going to vary based on which nerve(s) is damaged. One of the most disturbing symptoms of neuropathy is "deep" pain. This typically affects the feet first, travels up the legs somewhat, and then begins in the fingers and hands. An early sign of neuropathy may be tingling or burning in either the arms or legs, which along with the pain often start in the feet and legs.

As the neuropathy progresses, patients may actually start to lose sensation in the feet. This becomes problematic when patients try to walk, and cannot properly feel their feet under their body. Also, patients lose the ability to notice hot from cold on their feet, or not notice a blister or sore on the foot which can exacerbate readily.

Along with sensory problems, peripheral neuropathy may unfortunately cause muscle weakness. Patients may trip more often, legs may buckle, and a cane or walker may become necessary. Manual dexterity tasks such as buttoning shirts or handwriting may become difficult.

Organs may be affected by peripheral neuropathy as well. The heart may not provide warning pain (angina) of a heart attack due to neuropathy, leading to a "hidden" attack. Patients may experience digestive problems, stool inconsistencies, or swallowing issues.

Men may experience erectile dysfunction, and women may experience vaginal dryness. Both sexes may experience bladder problems with leaking or difficulty emptying.

What is the medical workup for peripheral neuropathy?

Every workup for peripheral neuropathy initially consists of a careful medical history and comprehensive physical examination. Depending on what is found during this workup, patients then may need varying studies.

Typically a set of laboratory studies is performed to establish electrolyte levels and look for disease markers.

One study that typically helps a lot is a nerve conduction study with an electromyography (EMG/NCV). This can tell which nerves are involved and the severity of the neuropathy. X-rays can show the extent of arthritis and rule out problems with bony areas. An MRI may be necessary to see if there is a source of nerve compression, such as a tumor or herniated disc.

A muscle biopsy may be necessary, and often a gait analysis can show how abnormal a person's walking truly is. With proper treatment, the gait may correct substantially.

The exact combination of studies necessary will be ordered depending on what the doctor needs to establish the diagnosis and severity and decide on treatment options.

What kind of treatments exist for peripheral neuropathy?

• Medications
  • Pain Medications — Opioids like Morphine may help substantially, or not at all. There are also non-narcotic pain medications such as Ultram which may provide relief.
  • Neurologic Modifying Agents — These include medications such as Lyrica, or Neurontin. They can help modulate the burning sensations from the neuropathy.
  • NSAIDS, Tylenol — Over the counter and inexpensive, these may help substantially for mild to moderate pain.
  • Antidepressants — They help with depression, but outside of that have shown success in modulating neuropathic pain. There are several different types, such as Tricyclic Antidepressants or Serotonin Reuptake Inhibitors.
  • Future agents — As more research is performed regarding proteins and factors causing peripheral neuropathy, more medications will become available to combat the progression and/or formation of the problem.
• Surgery
  • Certain types of peripheral neuropathy are amenable to a surgical solution.
  • For diabetic neuropathy and other types of polyneuropathy, the Dellon Procedure may assist substantially with alleviating pain and stopping the disease progression.
  • Depending on the cause of other types of neuropathy, other types of surgery may cure the problem.  For instance, if the problem is a mononeuropathy with tarsal tunnel syndrome, then releasing the nerve should most likely make the pain go away.

• Laser
  • Laser therapy uses specific wavelengths of light that have a strong anti-inflammatory effect on tissues and helps decrease the pain from peripheral neuropathy. Laser therapy is FDA cleared, painless, and immediately improves local blood circulation.

• Injections
  • If the neuropathy is amenable to a focal injection, steroid medication plus a numbing agent may work wonders for pain relief.
  • In addition, there is a new injection material available that is stem cell rich and also includes anti-inflammatory agents and proteins that may assist in reducing the pain of peripheral neuropathy substantially.

What should I expect with treatment results?

If the cause of the neuropathy can be established and it is treatable, the symptoms may be substantially improved. Such as with diabetes, patients may be able to get their blood sugars under control.

If a patient is an alcoholic and that's causing neuropathy, it should be ceased. If the blood tests show some vitamin or electrolyte abnormalities, replenishment may assist with the symptoms.

If surgery is indicated, the results will vary depending on the operation being performed along with how long the condition has been present.

Physical Therapy may help improve muscle weakness a lot, and the injections may decrease pain for months on end.

There are so many variations to peripheral neuropathy, it is too difficult to make broad sweeping treatment result statements.