Neuropathy

Neuropathy, strictly speaking, is any disease that affects the neurons of the nervous system. In practice, it is recognized as a peripheral disorder, potentially affecting nerves anywhere except the brain or the spinal cord. Nerves provide communication between brain and muscles, skin, internal organs and blood vessels. When damaged, nerves can't communicate properly, and that miscommunication causes symptoms such as pain or numbness. Sometimes the symptoms are much more serious. No medical treatments exist that can cure inherited peripheral neuropathy. However, there are therapies for many other forms.

Types of neuropathies

Neuropathies may affect just one nerve,- a condition called mononeuropathy, or several nerves - a condition called polyneuropathy. Peripheral nervous system is a part of nervous system that includes nerves in face, arms, legs, torso, and some nerves in the skull. In fact, all the nerves whaich are not located in central nervous system (which includes the brain and the spinal cord ) are peripheral nerves.




The four major forms of nerve damage are:

1.    polyneuropathy
2.    autonomic neuropathy
3.    mononeuropathy
4.    mononeuritis multiplex

The most common form is peripheral polyneuropathy, which mainly affects the feet and legs.

Peripheral polyneuropathy (PN)

As we already mentioned, peripheral neuropathy is caused by the damage to the peripheral nervous system, which transmits information from the brain and spinal cord to every other part of the body. More than 100 types of peripheral neuropathy have been identified, each with its own characteristic set of symptoms, pattern of development, and prognosis.

Symptoms of peripheral neuropathy

Some people may experience temporary numbness, tingling, and pricking sensations, sensitivity to touch, or muscle weakness, while others may suffer more extreme symptoms, including burning pain, muscle wasting, paralysis, or organ or gland dysfunction. If a sensory nerve is damaged, patient is likely to experience symptoms that may include:

•    Pain
•    Numbness
•    Tingling
•    Muscle weakness
•    Burning
•    Loss of feeling

In most cases these symptoms develop gradually and patient may have a tingling sensation or numbness that starts in toes or the balls of feet and spreads upward. For others, symptoms could be constant, and at night it may be almost unbearable. Other symptoms may include:

•    The sensation that you're wearing an invisible glove or sock
•    Burning pain
•    Sharp, jabbing or electric-like pain
•    Extreme sensitivity to touch, even light touch
•    Lack of coordination

In cases of motor nerves damages, the patient may have weakness or paralysis of the muscles controlled by those nerves. Bowel or bladder problems reduced sweating or impotence are also common. 

Possible causes of peripheral neuropathy

Neuropathies can be divided into two groups: inherited and acquired. Inherited forms of peripheral neuropathy are caused by inborn mistakes in the genetic code or by genetic mutations. Causes of acquired peripheral neuropathy include:

•    physical injury (trauma) to a nerve
•    tumors
•    toxins
•    autoimmune responses (rheumatoid arthritis and lupus)
•    nutritional deficiencies
•    alcoholism
•    vascular and metabolic disorders (diabetes)
•    reaction to some medications
•    bacterial or viral infections (Guillain-Barré syndrome)

Unfortunately, it's not always easy to detect the cause of peripheral neuropathy and sometimes the cause may never be found.

Risk factors for developing PN

•    Alcohol abuse
•    Vitamin deficiency
•    Immune system disorders
•    Other health problems including certain types of cancer, kidney disease and liver disease
•    Repetitive stress
•    Exposure to some toxic substances such as heavy metals - lead, mercury and arsenic; organic solvents; and certain medications

Complications of PN

Diabetic neuropathy may cause a number of complications. Damage to the nerves in your feet, along with poor circulation, can lead to ulcers and even gangrene.

Other complications include:

•    Partial or complete loss of movement or sensation
•    Low blood pressure
•    Impotence
•    Depression
•    Weight loss

Treatment of PN

•    Pain relievers
Acetaminophen and nonsteroidal anti-inflammatory drugs (aspirin and ibuprofen), can help relieve mild symptoms.

•    Anti-seizure medications
Drugs such as gabapentin (Neurontin), Carbamazepine (Tegretol) and phenytoin (Dilantin) are often prescribed for pain and they are very effective.

•    Tricyclic antidepressants
Antidepressant medications, such as amitriptyline, Nortriptyline (Pamelor), Desipramine (Norpramin) and imipramine (Tofranil), may provide relief for mild and moderate symptoms. They do so by interfering with chemical processes in brain that cause you to feel pain. 

•    Other medications
Opioid analgesics, such as codeine or oxycodone may be used to relieve pain. Mexiletine (Mexitil), a drug ordinarily used to treat irregular heart rhythms is sometimes also prescribed.

Autonomic neuropathy - AN

It is very important to make a difference between the peripheral and autonomic neuropathy because the latter represents damage to the nerves that regulate the body functions that patient can't control, including the nerves that regulate heart rate, blood pressure, perspiration and digestion. Similarly to the previous type, autonomic neuropathy results in faulty communication between your brain and the parts of your body that autonomic nervous system serves. Treatment of autonomic neuropathy involves the treatment of the underlying cause, if possible, and managing the signs and symptoms.

Symptoms of autonomic neuropathy

Signs and symptoms of autonomic neuropathy depend on which parts of autonomic nervous system are most affected. They may include:

•    a drop in blood pressure on standing
•    dizziness and fainting
•    trouble with urination and overflow incontinence and inability to bladder
•    sexual difficulties - impotence in men, and vaginal dryness and difficulties with arousal and orgasm in women
•    difficulty digesting food
•    abdominal bloating, nausea, vomiting and heartburn
•    cardiovascular problems
•    heat intolerance, especially during exercise
•    exercise intolerance
•    shakiness, sweating and palpitations

Possible causes of AN

A number of conditions can lead to damage of the autonomic nerves and these possible causes are similar to those for peripheral neuropathies. The most common cause is diabetes. 

Other causes may include:

•    Alcoholism
•    Amyloidosis- abnormal protein buildup in organs
•    Autoimmune diseases
•    Tumors
•    Multiple system atrophy
•    Surgical or traumatic injury to nerves
•    Certain medications, including chemotherapy drugs and Anticholinergics
•    Parkinson's disease and HIV/AIDS

AN complications

There are several possible complications of autonomic neuropathy and they include:

•    Mental and physical fatigue
•    Malnutrition and weight
•    Fluid or electrolyte
•    Sexual dysfunction and relationship problems
•    Urinary problems and infections
•    Cardiovascular complications
•    Kidney failure
•    Bladder problems

Treatment of AN

Several medications are available for treatment of each symptom. They include:

•    Gastrointestinal symptoms
Metoclopramide (Reglan, Metoclopramide HCL), fiber supplements, tricyclic antidepressants…

•    Sexual dysfunction
Sildenafil (Viagra), Vardenafil (Levitra) or Tadalafil (Cialis), vaginal estrogen cream (Premarin, Estrace), vaginal estrogen rings (Estring)…

•    Bladder problems
Bethanechol (Urecholine), Tolterodine (Detrol), Oxybutynin (Ditropan)…
 
•    Postural hypotension
High-salt diet, Fludrocortisone acetate (Florinef), Midodrine (ProAmatine)…

•    Sweating
Glycopyrrolate (Robinul, Robinul-Forte), Clonidine (Catapres)…

Therapies

•    Transcutaneous electrical nerve stimulation (TENS)
TENS is delivering tiny electrical impulses to specific nerve pathways through small electrodes placed on skin.
It is painless, but doesn't work for everyone.
•    Biofeedback
This method is based on learning a patient to control certain body responses that reduce pain.  
•    Acupuncture
It is proven that acupuncture can be an effective treatment for chronic pain, including the pain of neuropathy.  
•    Hypnosis
During hypnosis a patient receives suggestions intended to decrease perception of pain.
•    Relaxation techniques
These relaxation techniques are designed to help reduce the muscle tension. They range from deep-breathing exercises to visualization, yoga and meditation.