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Read The Flame within a guide to
prevent & treat autoimmune diseases by Dr Imran Khan
Peripheral neuropathy is a term used to describe
disorders of your peripheral nervous system.
Your peripheral nervous system includes nerves
in your face, arms, legs, torso, and some nerves
in your skull. In fact, all of your nerves not
located in your central nervous system — which
includes the brain and the spinal cord — are
peripheral nerves.
Neuropathies may affect just one nerve (mononeuropathy)
or several nerves (polyneuropathy). Your nerves
provide communication between your brain and
your muscles, skin, internal organs and blood
vessels. When damaged, your nerves can't
communicate properly, and that miscommunication
causes symptoms such as pain or numbness.
Peripheral neuropathy often affects people
with diabetes and autoimmune diseases such as
rheumatoid arthritis and lupus. Certain vitamin
deficiencies, some medications and alcoholism
can also damage peripheral nerves.
Treating the underlying condition may relieve
some cases of peripheral neuropathy. In other
cases, treatment of peripheral neuropathy may
focus on managing pain. Peripheral nerves have a
remarkable ability to regenerate themselves, and
new treatments for peripheral neuropathy using
nerve growth factors or gene therapy may offer
even better chances for recovery in the future.
Signs and symptoms
Neurological symptoms may occur related to
your central nervous system, which consists of
your brain and spinal cord, or your peripheral
nervous system, which links your spinal cord and
brain to all other parts of your body. The
extensive network of peripheral nerves includes
the motor nerves, which help your muscles
contract, and the sensory nerves, which allow
you to feel a range of sensations. In addition,
your peripheral nerves help control some of the
involuntary functions of the autonomic nervous
system, which regulates your internal organs,
sweat glands and blood pressure.
Unfortunately, peripheral nerves are fragile
and easily damaged. Damage to a peripheral nerve
can interfere with the communication between the
area it serves and your brain, affecting your
ability to move certain muscles or feel normal
sensations. Your symptoms will depend on the
cause of your neuropathy and on which nerve or
nerves are involved.
If a sensory nerve is damaged, you're likely
to experience symptoms that may include:
- Pain
- Numbness
- Tingling
- Muscle weakness
- Burning
- Loss of feeling
These symptoms often begin gradually. You may
have a tingling sensation or numbness that
starts in your toes or the balls of your feet
and spreads upward. Tingling might also begin in
your hands and extend up your arms. In some
cases your skin may become so sensitive that the
slightest touch is agonizing. You may also have
numbness, or even a complete lack of feeling, in
your hands or feet.
At times your symptoms may be barely
noticeable, and some people go years without
realizing anything is wrong. For others,
symptoms are constant, and especially at night
may be almost unbearable. Signs and 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
If your motor nerves are affected, you may
have weakness or paralysis of the muscles
controlled by those nerves. And if you have
damage to nerves that control certain functions
of the autonomic nervous system, you might have
bowel or bladder problems, reduced sweating or
impotence. You might also experience a sharp
fall in your blood pressure when you stand up,
which may cause you to faint or feel
lightheaded.
Causes
A number of factors can cause neuropathies.
When a single nerve is affected, the most likely
cause is trauma or some type of repetitive use
that puts pressure on the nerve. Nerve pressure
can result from using a cast or crutches,
spending a long time in an unnatural position —
such as typing at a computer keyboard — or
having a tumor or abnormal bone growth.
When damage occurs to several nerves, the
cause frequently is diabetes. At least half of
all people with diabetes develop some type of
neuropathy. Other common causes include
alcoholism, HIV/AIDS, inherited disorders,
amyloidosis and a deficiency of certain
vitamins, especially B vitamins.
Other causes of peripheral nerve damage may
include:
- Other
diseases. These include autoimmune
diseases, such as lupus and rheumatoid
arthritis, kidney disease, liver disease and
an underactive thyroid (hypothyroidism).
- Exposure to
poisons. These may include some
toxic substances and certain medications —
especially those used to treat cancer.
- Genetic
makeup. You may inherit a tendency
to develop peripheral neuropathy.
- Bacterial or
viral infections. An acute
condition called Guillain-Barre syndrome
frequently causes severe damage to all or
part of your peripheral nerves by destroying
the myelin sheath that covers nerve fibers.
The myelin sheath acts as an insulator for
your nerves and helps conduct nerve
impulses. Although the exact cause of
Guillain-Barre syndrome isn't known, most
cases occur after an infection, surgery or
immunization.
Unfortunately, it's not always easy to
pinpoint the cause of peripheral neuropathy. In
fact, if your neuropathy isn't associated with
diabetes, it's possible the cause may never be
found.
Risk factors
Having diabetes places you at high risk of
developing peripheral nerve damage. In fact, at
least half of people with diabetes have some
form of neuropathy. The risk increases the
longer you have diabetes, and is highest for
those who've had the disease for more than 25
years. Your risk is even greater if you are
older than 40 or have difficulty controlling
your blood sugar level.
Although researchers don't understand exactly
how damage occurs, a high blood sugar level
seems to impair your nerves' ability to transmit
signals. You can help reduce your risk by
carefully following a medically approved plan
for keeping your blood sugar level as close to
normal as possible.
Your risk of developing peripheral neuropathy
is also higher if you have one or more of the
following risk factors:
- Alcohol
abuse. Excessive drinking of
alcohol can affect your nervous system,
causing numbness of your hands and feet.
- Vitamin
deficiency. A lack of certain
vitamins, especially B-1 (thiamin) and B-12
makes peripheral neuropathy more likely.
Pernicious anemia, which occurs when your
body can't absorb B-12 properly, often leads
to peripheral neuropathy.
- Immune
system disorders. You're more
likely to develop peripheral neuropathy if
you have an autoimmune disease, such as
lupus or rheumatoid arthritis, or if your
immune system is compromised by the human
immunodeficiency virus (HIV) or AIDS.
- Other health
problems. Medical conditions,
including certain types of cancer, kidney
disease and liver disease, also can put you
at risk of nerve damage.
- Repetitive
stress. A job or hobby that puts
stress on one nerve for long periods of time
increases your chances of developing
peripheral neuropathy. In carpal tunnel
syndrome, for example, the median nerve that
extends through your wrist into your fingers
becomes compressed. Repetitive assembly line
work or work involving prolonged, heavy
gripping can compress the median nerve.
Playing golf, tennis or a musical instrument
and using vibrating power tools or even
crutches also can put pressure on peripheral
nerves.
- Toxic
substances. Exposure to some toxic
substances can make you susceptible to
peripheral nerve damage. These substances
include heavy metals, such as lead, mercury
and arsenic; organic solvents; and certain
medications, such as those used to treat
cancer or AIDS.
When to seek medical advice
See your doctor regularly if you have
diabetes, a compromised immune system or any
other chronic medical condition.
If you have a cut or sore on your foot that
doesn't seem to be healing, is infected or is
getting worse, see your doctor promptly,
especially if you have diabetes. Even minor
sores that don't heal can turn into ulcers. In
the most severe cases, untreated foot ulcers may
become gangrenous — a condition in which the
tissue dies — and require surgery or even
amputation of your foot.
Seek medical care right away if you notice
any unusual tingling, weakness or pain in your
hands or feet. Early diagnosis and treatment
offers the best chance for controlling your
symptoms and preventing further damage to your
peripheral nerves. If your symptoms are
interfering with your sleep or you feel
depressed, your doctor or pain specialist may be
able to suggest treatments that can help.
Screening and diagnosis
Peripheral neuropathy isn't a single disease,
but rather a syndrome with many causes. For that
reason it can be difficult to diagnose. To help
in the diagnosis, your doctor will likely take a
full medical history and perform a physical and
neurological exam that may include checking your
tendon reflexes, your muscle strength and tone,
your ability to feel certain sensations, and
your posture and coordination.
Your doctor may also request blood tests to
check your level of vitamin B-12, a urinalysis,
thyroid function tests and, often,
electromyography (EMG) — a test that measures
the electrical discharges produced in your
muscles. As a part of this test, you'll be asked
to have a nerve conduction study, which measures
how quickly your nerves carry electrical
signals. A nerve conduction study is often used
to diagnose carpal tunnel syndrome and other
peripheral nerve disorders.
Your doctor may recommend a nerve biopsy, a
procedure in which a small portion of a nerve is
removed and examined for abnormalities. But even
a nerve biopsy may not always reveal what's
damaging your nerves.
Complications
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. But it's not only your
feet that are vulnerable — diabetes-related
neuropathy can affect any organ in your body.
If nerves related to digestion are damaged,
for instance, your stomach may empty too slowly,
which may cause constant nausea, vomiting and
bloating. Or you may have frequent constipation
or diarrhea. In some cases you may have problems
with bladder control or impotence.
Other complications include:
- Partial or complete loss of movement or
sensation
- Low blood pressure
- Impotence
- Depression
- Weight loss
Treatment
The goal of treatment is to manage the
underlying condition causing your neuropathy and
repair damage, as well as provide symptom
relief. If your doctor hasn't been able to
determine the cause of your neuropathy, he or
she may try a variety of medications to see
which help ease your symptoms.
Controlling a chronic condition may not
eliminate your neuropathy, but it can play a key
role in managing it. Here's what your doctor may
recommend for treating various underlying
conditions:
- Diabetes.
If you have diabetes, you and your doctor
can work together to keep your blood sugar
level as close to normal as possible.
Maintaining normal blood sugar levels helps
protect your nerves, though your symptoms
may initially get worse before they begin to
improve.
- Vitamin
deficiency. If your neuropathy is
the result of a vitamin deficiency, it's
likely your symptoms will improve once the
deficiency is corrected. Your doctor may
recommend injections of vitamin B-12 daily
for a few days, then once a month. If you
have pernicious anemia, you'll need regular
injections for the rest of your life, and
possibly additional vitamin supplements.
You'll also need to eat a healthy diet.
- Autoimmune
disorder. If your neuropathy is
caused by an inflammatory or autoimmune
process, treatment will be aimed at
controlling your immune response.
- Nerve
pressure. In cases where neuropathy
is the result of pressure on a nerve,
treatment will likely focus first on
eliminating the source of the pressure. That
might mean adding ergonomic chairs, desks or
keyboards to your home or office, changing
the way you hold tools or instruments, or
taking a break from certain hobbies or
sports. In some cases of nerve compression,
you may need surgery to correct the problem.
- Toxic
substances or medications. If
toxins or medications are responsible for
the neuropathy, it's critical that you stop
taking the medication or avoid further
exposure to the toxin to prevent the
neuropathy from progressing further.
Medications
Medications can ease pain symptoms, but most
have side effects, especially if you take them
for long periods of time. If you take pain
medication regularly, including over-the-counter
(OTC) products, discuss the benefits and side
effects with your doctor. Medications that may
help provide pain relief for neuropathy include:
- Pain
relievers. OTC pain relievers, such
as acetaminophen (Tylenol, others), and
nonsteroidal anti-inflammatory drugs (NSAIDs),
such as aspirin and ibuprofen (Advil,
Motrin, others), usually help mild symptoms.
For more severe symptoms, your doctor may
recommend prescription NSAIDs. If you take
NSAIDs for long periods of time or in large
doses, you may develop nausea, stomach pain,
bleeding or even ulcers.
- Anti-seizure
medications. Drugs such as
gabapentin (Neurontin), carbamazepine (Tegretol)
and phenytoin (Dilantin) were originally
developed to treat seizure disorders
(epilepsy). However, doctors often also
prescribe them for jabbing pain. Side
effects may include drowsiness and
dizziness.
- Lidocaine
patch. This patch contains the
topical anesthetic lidocaine. You apply it
to the area where your pain is most severe,
and you can use up to three patches a day to
relieve pain. This treatment has almost no
side effects except, for some people, a rash
at the site of the patch.
- Tricyclic
antidepressants. Antidepressant
medications, such as amitriptyline,
nortriptyline (Pamelor), desipramine (Norpramin)
and imipramine (Tofranil), may provide
relief for mild to moderate symptoms by
interfering with chemical processes in your
brain that cause you to feel pain. Common
side effects of these medications may
include balance problems, dry mouth, nausea,
tiredness, constipation and weight gain. To
help reduce these side effects, your doctor
will likely start you off at a low dose and
slowly increase the amount of drug you take.
If you're bothered by insomnia, your doctor
may also recommend an antidepressant or a
sleeping medication. Some studies have also
suggested that selective serotonin reuptake
inhibitors (SSRIs), such as paroxetine (Paxil)
and fluoxetine hydrochloride (Prozac), may
help relieve the signs and symptoms of
peripheral neuropathy.
- Other
medications. Opioid analgesics,
such as codeine or oxycodone (OxyContin) may
be used to relieve pain. However, this class
of medications produces numerous side
effects, including addiction, that make
long-term use of these drugs undesirable.
Mexiletine (Mexitil), a drug ordinarily used
to treat irregular heart rhythms, sometimes
helps relieve burning pain.
Research aimed at finding more effective
treatments for peripheral neuropathy is ongoing.
For example, researchers are looking at
developing nerve growth factors to reproduce the
chemicals that signal your body to repair small
nerve fibers. Unfortunately, no medications can
repair nerve damage yet, but the body can
regenerate nerves if the offending substance is
removed.
Therapies
Several drug-free therapies and techniques may
also help with pain relief. Doctors frequently
use them in conjunction with medications, but
some may be effective on their own. They
include:
-
Transcutaneous electrical nerve stimulation
(TENS). Your doctor may prescribe
this therapy, which may help prevent pain
signals from reaching your brain. TENS
delivers tiny electrical impulses to
specific nerve pathways through small
electrodes placed on your skin. Although
safe and painless, TENS doesn't work for
everyone or for all types of pain.
- Biofeedback.
This therapy uses a special machine to teach
you how to control certain body responses
that reduce pain. You then learn how to
control these same responses yourself.
Biofeedback techniques are often taught in
medical centers and hospitals.
- Acupuncture.
The National Institutes of Health has found
that acupuncture can be an effective
treatment for chronic pain, possibly
including the pain of neuropathy. Keep in
mind that you may not get immediate relief
with acupuncture and may require more than
one session.
- Hypnosis.
Many adults can be hypnotized by a trained
professional, but for hypnosis to be most
effective, you also have to be a willing and
motivated participant. During hypnosis,
you'll typically receive suggestions
intended to decrease your perception of
pain.
- Relaxation
techniques. Designed to help reduce
the muscle tension that makes pain worse,
relaxation techniques range from
deep-breathing exercises to visualization
(imagining yourself floating in a tropical
ocean, for example), yoga and meditation.
You might want to take classes in one or
more of these techniques, or you can learn
them yourself using books or tapes.
Prevention
The best way to prevent peripheral neuropathy
is to carefully manage any medical condition
that puts you at risk. That means controlling
your blood sugar level if you have diabetes or
talking to your doctor about safe and effective
treatments if you think you may have a problem
with alcohol.
Whether or not you have a medical condition,
eat a healthy diet that's rich in fruits,
vegetables, whole grains and lean protein. The
best food sources of vitamin B-12 are meats,
fish, eggs, low-fat dairy foods and fortified
cereals. If you're a strict vegetarian,
fortified cereals are a good source of vitamin
B-12 for you, but you may also want to talk to
your doctor about B-12 supplements.
As much as possible, avoid repetitive
motions, cramped positions and toxic chemicals,
all of which may cause nerve damage.
Self-care
The following suggestions can help you manage
peripheral neuropathy:
- Take care of
your feet, especially if you have diabetes.
Check your feet daily for signs of blisters,
cuts or calluses. Tight shoes and socks can
worsen pain and tingling and may lead to
sores that won't heal. Wear soft, loose
cotton socks and padded shoes. You can use a
semicircular hoop, which is available in
medical supply stores, to keep bedcovers off
hot or sensitive feet.
- Exercise.
Ask your doctor about an exercise routine
that's right for you. Regular exercise may
reduce neuropathy pain and can help control
blood sugar levels.
- Quit
smoking. Cigarette smoking can
affect circulation, increasing the risk of
foot problems and possibly amputation.
- Eat healthy
meals. If you're at high risk of
neuropathy or have a chronic medical
condition, healthy eating is especially
important. Emphasize low-fat meats and dairy
products and include lots of fruits,
vegetables and whole grains in your diet.
Drink alcohol in moderation.
- Massage your
hands and feet, or have someone massage them
for you. Massage helps improve
circulation, stimulates nerves and may
temporarily relieve pain.
- Avoid
prolonged pressure. Don't keep your
knees crossed or lean on your elbows for
long periods of time. Doing so may cause new
nerve damage.
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