Peripheral Neuropathy: Part 2 - What are its symptoms and is treatment available?

Last week, we learned that Peripheral Neuropathy (PN) affects the peripheral nervous system, the network of nerves that transmits information from th
e central nervous system (brain and spinal cord) to the rest of the body. It was noted that PN is not a single disease, but is a condition with over 100 causes in which transmission of information from peripheral nerves is disrupted. Today we'll look at the specific symptoms of PN and discuss its diagnosis and treatment.

What are the symptoms of Peripheral Neuropathy? Symptoms of PN vary depending on the type of peripheral nerve (sensory, motor, or autonomic) affected. Although some neuropathies may affect all three types of nerves, others primarily affect one or two types.

Most commonly, PN affects sensory nerves. These are the nerves that are responsible for the sense of touch. Detecting heat, pain, cold, and position sense are all functions of sensory nerves. Sensory nerve involvement typically begins with the gradual onset of numbness and tingling in the feet or hands, a symptom known as "paresthesias". This sensation frequently occurs in a "stocking" or "glove" distribution, affecting the entire foot or hand. In more severe cases, burning or shock-like pain may develop. Sensory nerve involvement resulting in the inability to detect pain is a particularly serious problem for people with diabetes, contributing to a high rate of lower limb amputations from infections and burns. When PN affects sensory nerves in the feet, people may have loss of position sense making walking or maintaining their balance difficult.

Autonomic neuropathy occurs when there is damage to the nerves that manage unconscious body functions such as blood pressure, heart rate, sweating, bowel and bladder function, and digestion. Symptoms of PN affecting autonomic nerves vary, depending on which organ or system of the body is involved. Constipation, diarrhea, nausea after eating, and bloating may develop when PN affects the gastrointestinal tract. Other symptoms that occur with autonomic PN include the inability to sweat normally leading to heat intolerance, loss of bladder control, and the inability to maintain safe blood pressure levels which can cause dizziness, lightheadedness, or even fainting.

Motor neuropathy symptoms may include muscle weakness, cramps, muscle twitching, and loss of muscle mass. In an acute type of motor neuropathy, called Guillain-Barré syndrome, severe weakness starting in the legs spreads upward sometimes causing total body paralysis.

How is Peripheral Neuropathy Diagnosed? Diagnosing peripheral neuropathy is often difficult because the symptoms are highly variable and the list of potential causes is lengthy. There is no specific test available to make the diagnosis of PN. A history of chronic illnesses, such as diabetes, as well as learning about family history, dietary issues, work environment, alcohol use, risk of HIV or other infections can provide important clues to the underlying cause. Blood tests can help with the detection of diabetes, infections, immune system disease, vitamin deficiencies, and kidney disease, all of which can lead to the development of PN. Additional testing such as MRI scanning, nerve conduction studies (NCV), and tests of muscle activity (EMG) may be required if the information found from history, physical and blood testing are inconclusive.

Is there treatment for Peripheral Neuropathy? Treatment is most effective when an underlying cause for the PN is found. For example, if the peripheral nerve damage is found to be related to a vitamin deficiency, supplying that vitamin will often stop or reverse the process. Likewise, PN due to toxins or medications can be corrected by avoiding further exposure to the offending agent. With diabetes-related PN, appropriate treatment measures and careful monitoring to keep blood sugars in an optimal range has been shown to improve symptoms and slow progression of the neuropathy. Surgery may even be the most appropriate treatment, as with PN from carpal tunnel syndrome that has not responded to conservative measures.

Nerve-related pain is a particularly common problem in the sensory type of PN. When over-the-counter pain relievers are ineffective, prescription medications including (Neurontin®), mexiletine (Mexitil®), phenytoin (Dilantin®), carbamazepine (Tegretol®) and amitriptyline (Elavil®) may be of benefit. In more severe cases, anesthetic nerve blocks may be used to block the source of the nerve pain.

When PN primarily affects motor nerves, hand or foot braces, specialized exercise programs, and physical therapy are used to help with muscle weakness.

Treatment of autonomic neuropathy hinges on its symptoms and organs affected. Overactive bladder is a common symptom when autonomic nerves controlling bladder function are affected. Medications including tolterodine (Detrol) and oxybutynin (Ditropan XL) will help with this urinary tract complaint. Other treatments are available if the neuropathy concerns other autonomic functions such as blood pressure, digestion, or sweating.

Even though most cases of PN cannot be cured, there is usually some treatment available that will help with its symptoms. The best results, however, occur with early diagnosis and treatment since peripheral nerves have a limited capacity for regeneration.

Peripheral Neuropathy: Part 1 - What is the Peripheral Nervous System and what is Peripheral Neuropathy?

Peripheral Neuropathy (PN) is one of the most common, yet least well known, chronic conditions in the U.S., affecting over 20 million people. PN is not a single disease, but is a group of over 100 disorders that occur due to various conditions affecting the peripheral nervous system.

What is the Peripheral Nervous System? The nervous system is made up of two main parts, the central nervous system that includes the brain and the spinal cord, and the peripheral nervous system. Peripheral nerves extend from the central nervous system to supply nerve function to the muscles, skin, and internal organs. There are three types of peripheral nerves -1) sensory nerves that sense heat, pain or touch, 2) motor nerves that control muscle activity, and 3) autonomic nerves that control functions such as heart rate, breathing, and digestion.

What is peripheral neuropathy? Loosely translated, "neuropathy" means disease affecting nerves. In the case of PN, peripheral nerves become damaged or diseased and are unable to communicate messages between the central nervous system and the portion of the body that they supply. Any of the three types of peripheral nerves - sensory, motor, and autonomic - can be affected by PN. Some of the more common manifestations of PN include: pain, numbness or tingling of the hands or feet, problems affecting bowel or bladder function, and muscle weakness.

What Causes Peripheral Neuropathy? There are many causes of PN, but in up to a third of cases, an underlying cause is never found. These cases are known as "idiopathic". Another third of cases of PN are caused by complications from diabetes. Diabetes causes damage to peripheral nerves as a result of long-standing elevated blood sugar levels. Up to one half of diabetics will eventually develop some type of peripheral neuropathy. The remainder of cases of PN occurs from a variety of causes including:

• Injuries - Fractures, frostbite, or pressure from ill-fitting casts that also damage nearby peripheral nerves.
  
• Chronic kidney failure - Due to failure of elimination of toxins from the body (uremia)
  
• Infections - Lyme disease, shingles, hepatitis C, and HIV/AIDS
  
• Nutritional deficiencies - B vitamins (B-1, B-6 and B-12), Vitamin E, and niacin are important in nerve health.
  
• Autoimmune disease - Lupus, Rheumatoid Arthritis
  
• Alcoholism - From the effect of alcohol directly, as well as to associated nutritional deficiencies
  
• Toxins and medications - Heavy metals, such as mercury, and cancer chemotherapy
  
• Tumors - Both benign and malignant, usually from pressure on peripheral nerves.
  
• Nerve compression - "Tunnel Syndromes" including carpal tunnel, cubital tunnel, and thoracic outlet syndromes.

As we look further into Peripheral Neuropathy in next week's Health Tip, it is important to remember that PN is not a disease itself, but is a manifestation of damage to peripheral nerves that can occur from a variety of causes.

Updated Exercise Guidelines

By now, almost everyone is aware that regular physical activity offers a number of health benefits including:

• Delaying death from all causes
  
  
• Decreasing the risk of developing coronary heart disease, heart attack, and stroke
  
  
• Lessening the likelihood of developing type 2 diabetes
  
  
• Reducing the risk of certain cancers including breast and colon cancer
  
  
• Improving blood pressure control in hypertensive individuals
  
  
• Preserving bone mass and reducing the risk of developing osteoporosis
  
  
• Improving mood in mild-to-moderate depression
  
  
• Lowering the risk of cognitive decline and dementia

What is not clear to many people is the amount and type of exercise necessary to achieve these benefits. Since 1998, the American College of Sports Medicine (ACSM) has periodically issued exercise guidelines geared toward the average individual who is interested in improving their physical fitness and health. Their latest position statement, issued in 2012, provides evidence-based guidance to health and fitness professionals to help with the development of individualized exercise prescriptions for healthy adults of all ages. Let's look at those recommendations and see if you are getting the appropriate types and amount of exercise as defined by the ACSM. The ACSM recommendations, categorized to the major types of fitness---cardiorespiratory, strength training, flexibility, and neuromotor exercise training, are as follows:

1. Cardiorespiratory Exercise, also known as "aerobic" or "cardio" exercise, utilizes major muscles such as those in the arms and legs walking while increasing heart and respiratory rate. Examples of this type of exercise include jogging, aerobic dancing, rowing and bicycling. The ACSM advises that adults should get at least 150 minutes of moderate-intensity cardiorespiratory exercise each week. One way of reaching this goal would be to perform 30 minutes (or more) of moderate-intensity exercise on 5 days during the week. Alternatively, the goal could be reached with multiple shorter sessions of at least 10 minutes during the week.
   
   
2. Resistance Exercise or "weight training" is defined as exercise that causes the muscles to contract against an external resistance with the expectation of increasing strength, tone, mass, and/or endurance. Many people see this as "pumping iron", with heavy weights, but actually lifting, pushing, or pulling against resistance at higher repetitions (10-20) with lower weights is best for most people. The ACSM recommends that adults train each major muscle group two or three days each week. The use of free weights, dumbbells, weight machines, and resistance bands are all appropriate ways of reaching this goal. It is advised that adults wait at least 48 hours between resistance training sessions.
   
   
3. Flexibility Exercises or "stretching exercises" are designed to improve range of motion in the back and joints. The ACSM advises performing flexibility exercises at least two or three days each week. A description of some of the most important stretching exercises can be found here. It is advised that each stretch should be held for 10-30 seconds to the point of tightness and repeated four times. Flexibility exercises should be done at least two or three days each week. In general, flexibility exercises are most effective when the muscle is warmed up following a hot bath or light aerobic activity.
   
   
4. Neuromotor Exercise is a new addition to the regular ACSM exercise guidelines. Neuromotor exercise is sometimes called "functional fitness training" and incorporates motor skills such as balance, coordination, gait, and agility, and proprioceptive training. Examples of this type of exercise include yoga and tai chi, the ancient Chinese exercise that involves a series of movements performed in a slow, focused manner. Neuromotor exercise is particularly beneficial for older individuals to help prevent falls. The ACSM recommends that this type of exercise be performed for 20-30 minutes, two or three days per week.

It is important that any new exercise program, particularly in those over the age of 50 or with chronic medical problems, be initiated after receiving clearance from your doctor. In some cases, as with resistance training and neuromotor exercise, it may be best to consult a qualified trainer or physical therapist to assure that the exercises are being performed safely and effectively. The ACSM stresses that if these levels of activity cannot be reached there are still health benefits that can be gained from lower amounts of exercise. Go here to read the full report from the ACSM.