Diabetic Peripheral Neuropathy
Description
The next time you get a blister, stub your toe into the corner of your
dresser, or step on one of those little plastic building bricks, you might
wish that your foot was not able to feel anything at all. But the truth is
that having little or no feeling in your feet can cause a whole host of
problems.
People with diabetes are especially prone to nerve damage (neuropathy),
although this damage can also be caused by excessive alcohol, AIDS, and
other disorders. Because the ends of long nerves tend to be affected first,
the extremities of the body such as hands and feet are usually the first to
show symptoms. While it’s not certain what exactly causes this nerve
damage, it’s likely that it has something to do with high blood sugar
levels. Because diabetics are either not able to produce insulin (a hormone
that helps the body process sugar), or their tissues don’t respond to the
insulin that’s produced, the levels of sugar in their blood (unless tightly
controlled) may become abnormally high, causing damage to blood vessels and
nerves.
There are three types of nerves, and each is affected by this diabetic
peripheral neuropathy.
- The first group, and possibly the one you thought of first, is made up
of sensory nerves. These nerves are able to feel touch, temperature,
pain, and so on. As these nerves become damaged, patients may lose
their ability to perceive hot and cold, sharp and dull objects, and
may even completely lose all sense of touch in the foot. With this
loss of sensation, patients may be unable to feel when their feet are
becoming irritated or have been injured. They may continue walking on
the injured foot and will fail to seek treatment for the injuries
they’re unaware of. This may result in ulcers, Charcot’s foot, or
other difficulties. As nerves become damaged, some people may also
experience an increase in pain (usually burning or tingling
sensations) which can become quite severe. - Autonomic nerves help control body functions we don’t think about,
such as sweating, heart rate, digestion, etc. As these nerves are
damaged, the feet may lose their ability to produce oils and sweat,
and may become dried out. Dry skin can crack, resulting in infections,
which can become quite serious since diabetics also tend to have
problems with healing. - Motor nerves control the movement of muscles and muscle tone. When
these nerves lose their function, the foot may become deformed or
distorted because the muscles holding everything in place are
weakened. Bunions and hammertoes may develop, and corns and calluses
may show up where the pressure on the foot has changed, or where shoes
begin to rub the foot in unusual areas. These can turn into ulcers and
become infected.
Sores on your feet may not seem like a big deal, but people with diabetes
have trouble healing (due to poor circulation caused by blood vessel
damage). Without proper care (and unfortunately, sometimes with it), sores
or infections can easily become larger and spread, resulting in gangrene
(tissue death), possible amputations of the foot or leg, and sometimes even
death.
This is why early detection of problems is so important in patients with
neuropathy. If issues are caught early on, they’re much more likely to
respond to treatment, thus avoiding amputation.
Of course, the first step in all of this is to try to prevent nerve damage
in the first place. To that end, people with diabetes should monitor their
blood sugar level closely and keep it in target range. Because once nerves
are damaged, there’s no known cure. Neuropathy usually shows up in patients
with poorly managed blood sugar levels, but all people with diabetes are
still at risk. If you have diabetes, discuss any symptoms you may
experience with your doctor, who can help you form a treatment plan.
Symptoms
Neuropathy comes on gradually, and patients may be affected by it before
they even discover they have diabetes. This condition may manifest itself
in different ways, depending on the type (or types) of nerves that are
affected.
- Sensory nerve damage often starts as a numb feeling or tingling
sensation in the feet. These sensations usually begin at the toes and,
as the nerve damage gradually progresses, they work their way up the
foot and into the ankle. Some people may also experience burning or
sharp prickly pain in their feet and legs. Once the feet have become
numb, it may feel as though you’re wearing socks, even when you’re
not, or you may feel as if you’re walking on cotton or a water-filled
cushion. Unless you’re taking a stroll over your waterbed at the time,
you should discuss these sensations with your doctor. You may also
find it rather harder to walk, since you can’t quite tell where your
feet are. You may even change the way you walk (widening your stance
or dragging your feet), without realizing it as you try to compensate
for your change in sensation. - Autonomic neuropathy may manifest itself as dry skin on your feet. The
skin over the heel or calluses may become particularly prone to
cracking. - Damage to the motor nerves may result in weakness or a loss of tone in
the lower legs or feet. You may find it harder to keep your balance,
and again, may make unconscious compensations for it while walking. As
the muscles of your foot weaken, the shape of your foot may also
change, possibly resulting in the formation of bunions, hammertoes, or
other deformities.
Diagnosis
If you suspect that you may be experiencing neuropathy, even if you don’t
think you have diabetes (but especially if you do have diabetes), go see
your foot doctor as soon as possible. He or she will likely make the
diagnosis by taking your medical history, discussing your symptoms with
you, and performing a physical exam. He or she may also use a number of
different tests to check your nerve function. These tests may include the
filament test, in which a monofilament (a soft nylon fiber) is placed or
brushed against the foot. If you’re unable to feel it, you may have nerve
damage. Some doctors also use nerve conduction studies, which measures how
quickly your nerves carry electrical signals. Electromyography (EG) tests
the electrical discharges produced in your muscles, and quantitative
sensory testing measures your ability to feel vibrations and hot and cold
sensations. Your doctor may also choose to perform autonomic testing which
tests your blood pressure or ability to sweat.
Treatment
Unfortunately, there is no known cure for peripheral neuropathy, so once
the damage has been done to your nerves, it’s impossible to reverse. The
bulk of the treatment, then, focuses on prevention, both of further damage
to the nerves and of problems associated with neuropathy, although there
are medications available to ease symptoms if they are painful. Oral pain
relievers are often used, or sometimes antidepressants or anti-seizure
medications are prescribed to treat pain from damaged nerves.
- Preventing further nerve damage
- In order to prevent, as much as possible, further damage to your
nerves, it’s necessary that you keep your blood sugar level
under firm control. Your doctor can best assist you with finding
your target range, but for the most part, target blood glucose
level ranges are between 70 and 130 mg/dL (or 3.9 to 7.2 mmol/L)
before meals, and less than 180 mg/dL (or 10 mmol/L) two hours
after a meal. - You’ll also want to take an A1C test at least twice a year (more
if you have trouble controlling your blood sugar level or have
had a change in your medications). This test measures how much
sugar has attached to the hemoglobin (the substance that carries
all that oxygen around) in your blood. If your average blood
sugar level has been low, your A1C number will be lower.
However, if your average blood sugar level has been high, your
A1C number will rise. In essence, it tests your average blood
sugar level for about the past two or three months. When tested,
the number should be less than 7%. (People without diabetes tend
to average 4 to 6%.) - Other preventive measures include keeping your blood pressure
under control (diabetic patients frequently also suffer from
high blood pressure), maintaining a healthy weight (including
following a diet plan discussed with your doctor as well as
frequent exercise), and avoiding smoking and the consumption of
alcohol.
- In order to prevent, as much as possible, further damage to your
- Preventing foot problems
- First of all, be sure to get to know your local podiatrist.
Schedule appointments at least twice a year, and let him or her
know you have diabetes. Frequent screening for foot issues can
catch minor problems before they become crises. Also, see your
doctor immediately if you experience any warning signs, such as
redness, swelling, bruising around or under calluses, blisters,
cracks, cuts, or feet that have changed shape or feel unusually
warm or hot to the touch. (It’s also a good idea to go in if,
for instance, you find a tack stuck in the bottom of your foot.) - Inspect your feet every day. Check for the warning signs above,
especially around the sole of your foot. If you can’t reach your
foot or see it very well, use a mirror or ask a friend or family
member to help you out. (They’ll get good karma and you’ll get
an inspected foot, so it’s a pretty good deal all around.) - Wash your feet daily. Use water that’s lukewarm, not hot (test
the water with a sensitive part of your skin, such as your
elbow, or wet a cloth and put it against your face), and don’t
soak your feet unless your doctor instructs you to. Gently dry
your feet with a soft towel, paying particular attention to the
space between your toes. (You want to avoid fungal infections,
which are always ugly things but can be even worse if you have
diabetes.) If the skin of your feet is dry, apply a thin film of
moisturizer (Cetaphil cream is recommended), although again,
avoid getting it between your toes. - Wear shoes that fit well. You should never have to break in a
pair of shoes, so don’t buy anything that feels uncomfortable
when you first wear it. Choose shoes with a generous toe box
(about 3/4″ of space between your big toe and the front of the
shoe), and flexible, breathable uppers (leather is best) that
fully cover your feet. Never wear high heels, sandals, slippers,
or other shoes with open toes or heels (especially the kind with
the thong between the toes). Running or walking shoes often work
best (New Balance brand is recommended). Always check the
insides of your shoes for rough lining, seams, or foreign
objects (like that plastic toy soldier your child dropped
earlier). And avoid socks or stockings with seams, since these
can cause irritation to your feet.
- First of all, be sure to get to know your local podiatrist.
It’s true that once you’ve developed neuropathy, there are a lot of things
to keep in mind, and there may be a lot of changes to make. It can seem
pretty intimidating, in fact, and even discouraging. But the truth is that
many people have experienced and are experiencing the same thing, and would
likely be willing to talk to you and offer advice, or just sympathize.
And the good news is that following your doctor’s guidelines can really
help a lot. While problems do sometimes still develop, even when you’re
doing everything right, they’re much, much less likely. So, with a bit of
adjustment (and a wee bit of luck), you should be able to live a normal,
healthy, and long life.
Call 719-543-2476 today to schedule your appointment!
