Understanding Types Of Neuropathy

Today's post from raphaelkellmanmd.com (see link below) is a general post about neuropathy with special reference to some of the common causes of neuropathy across the world. It's extremely useful for people new to the disease but also contains information which everybody living with neuropathy may find useful. We may think we know everything there is to know about our condition but there's always something new to learn and each piece of new information increases our understanding of nerve damage. A useful read.

 Neuropathy
The Kellman Center for Integrative and Functional Medicine Jan 2015

Peripheral neuropathy affects two- thirds of people with diabetes, 10- 20% of people with cancer and 8% of all people over age 55. Neuropathy or nerve pain is caused by a wide range of problems that lead to injury and dysfunction of nerves. Since the nerves affected are outside the brain (in the periphery) neuropathy is often referred to as peripheral neuropathy.

Peripheral neuropathy can cause pain, tingling or numbness, and burning. Pain associated with neuropathy can be severe and often described as stabbing, shooting, burning or crushing. It also has an electric quality about it. Although the pain is usually unprovoked sometimes even a light stimulus (such as light touch across the skin) may be experienced as excruciating. Neuropathy can be caused by a number of factors. These include diabetes, hypothyroidism, infections such as shingles from herpes zoster, toxins including heavy metals, and nutrient deficiencies.

Diabetic neuropathy is the most common cause of neuropathy in the US. Variations in symptoms are common and the feet, which are most often affected, may feel both at the same time numb and painful. Many factors contribute to neuropathy in diabetes.

These include:
Free radicals
Glycation of proteins (distortion and damage) due to excess glucose
Secondary vitamin deficiencies such as vitamin B1, B6,B12, glutathione
Decreased circulation
Accumulation of toxic byproducts

Since neurons (nerve cells) do not require insulin for glucose uptake, diabetics tend to accumulate excess glucose in neurons. Glucose subsequently converted to sorbitol by an enzyme known as aldose reductase. The sorbitol accumulates in the nerve cells causing free radical damage. It can also cause a decrease in various nutrients and antioxidants such as taurine, carnitine, vitamin C and Myo-inositol which is partly responsible for nerve conduction. Diabetes is also associated with decreased nitric oxide production which leads to vascular dysfunction. The end result is increased oxidative stress and subsequent cellular dysfunction and neuropathy.

Excess glucose can bind to protein and can cause damage. These damaged proteins are called advanced glycation end products or AGEs. The formulation of AGEs is a major factor in the aging process. These damaged proteins can damage cells such as neurons and organs, cause wrinkles, and cause brown spots on the skin. AGEs can also contribute to neuropathy and other complications seen in diabetes. AGEs create more free radicals and can activate the pro-inflammatory messenger molecules called TNF- alpha. TNF- alpha has been shown to be high in inflammatory diseases of the central nervous system such as Alzheimer’s, Parkinson’s, and Multiple Sclerosis.
AGEs formation is increased under conditions of oxidative stress such as glutathione depletion. ­Carnosine is a natural inhibitor of AGEs and is found in high concentrations in the brain. It plays an important role in the treatment of neuropathy.

Hypothyroidism can also cause neuropathy. Hypothyroidism is associated with fatigue and weight gain but at times the only symptom can be pain. Frequently, the routine thyroid blood test fails to detect the problem, and a more sensitive test called the TRH stimulation test is necessary. Infection is another cause of neuropathy. Infectious neuropathy is caused by certain viruses. The most noted example is the varicella- zoster virus. This virus causes chicken pox which then can become inactive in sensory nerves. Years later the virus can be reactivated and cause a condition called shingles. HIV virus can also cause neuropathy.

Physical injury to nerves is another cause of neuropathy. Pressure and the stretching of nerves and the concomitant diminution in blood supply of oxygen and nutrients cause the nerve to become dysfunctional. This type of injury can involve more than one nerve. Overstretching the nerves that span from the neck to the arm is a common example of this type of nerve injury and neuropathy. Symptoms include pain, tingling, and numbness that can be in the neck or travel down the arm.

Drug induced neuropathy caused by drugs usually involves sensory nerves on both sides of the body particularly in the hands and feet. Flagyl, the cholesterol lowering medication Simvastatin, HIV medications, Dilantin and Isoniazid are examples of drugs that can cause neuropathy.

Toxin induced neuropathy can be caused by a wide variety of industrial chemicals, and heavy metals. Chemicals such as acrylamide, alomide, Allyl chloride and carbon disulfide are associated with neuropathy. Organic compounds such as N. Hexane and Toluene can also cause sensory motor neuropathy. Heavy metals such as lead, mercury, and arsenic can also cause neuropathy. Lead tends to affect motor neurons more than sensory neurons.

Neuropathies can also affect motor nerves. If neuropathy continues over a period of time muscle tone can diminish, and muscle shrinkage or atrophy can result. If the autonomic nerves are affected (the nerves that affect the organs), dizziness and light headedness can result. Palpitations and fast heart rate can also be a symptom of autonomic neuropathy. Other indicators of autonomic dysfunction include lack of sweat, tears and saliva. Impotence or erectile dysfunction, gastrointestinal dysfunction, constipation and urinary retention can also result from autonomic dysfunction.

http://raphaelkellmanmd.com/specialties/neuropathy/