Diabetic neuropathy

Dr. Ebtissam Zakaria
Prof. of Internal Medicine & Diabetes
Faculty of Medicine, Cairo University

Introduction
Diabetic neuropathy is a type of nerve
damage that can occur if you have diabetes. High blood sugar (glucose) can injure nerves throughout your body. Diabetic
neuropathy most often damages nerves in your legs and feet.
Depending on the affected nerves, symptoms of diabetic neuropathy can
range from pain and numbness in your legs and feet to problems with your
digestive system, urinary tract, blood vessels and heart. Some people have
mild symptoms. But for others, diabetic neuropathy can be quite painful and
disabling.
Diabetic neuropathy is a common and serious complication of diabetes. But
you can often prevent diabetic neuropathy or slow its progress with tight blood
sugar control and a healthy lifestyle.

Symptoms
There are four main types of diabetic
neuropathy. You can have one or more
than one type of neuropathy. Your
symptoms will depend on the type you
have and which nerves are affected.
Usually, symptoms develop gradually.
You may not notice anything wrong
until considerable nerve damage has
occurred.
1-Peripheral neuropathy
Peripheral neuropathy is the most
common type of diabetic neuropathy. It affects the feet and legs frst,
followed by the hands and arms. Signs
and symptoms of peripheral neuropathy are often worse at night, and may
include:
•Numbness or reduced ability to feel
pain or temperature changes
• Tingling or burning sensation
•Sharp pains or cramps
• Increased sensitivity to touch — for
some people, even the weight of a
bedsheet can be painful
• Muscle weakness
• Loss of reflexes, especially in the ankle
• Loss of balance and coordination
•Serious foot problems, such as ulcers,
infections, and bone and joint pain
2- Autonomic neuropathy
Theautonomic nervous system controls your
heart, bladder, stomach, intestines, sex
organs and eyes. Diabetes can affect
nerves in any of these areas, possibly
causing:
• A lack of awareness that blood sugar

levels are low
( h y p o g l y c e m i a
unawareness)
• Bladder problems,
including urinary
tract infections or
urinary retention
or incontinence
• Constipation,
uncontrolled diarrhea or both
• Slow stomach
emptying (gastroparesis), causing nausea, vomiting,
bloating and loss of appetite
• Difculty swallowing
• Increased or decreased sweating
• Problems controlling body temperature
• Changes in the way your eyes adjust
from light to dark
• Increased heart rate at rest
• Sharp drops in blood pressure after
sitting or standing that may cause you
to faint or feel lightheaded
• Erectile dysfunction
• Vaginal dryness
• Decreased sexual response
3- Radiculoplexus neuropathy (diabetic amyotrophy)
Radiculoplexus neuropathy affects
nerves in the thighs, hips, buttocks
or legs. It›s more common in people
with type 2 diabetes and older adults.
Other names for this type are diabetic
amyotrophy, femoral neuropathy or
proximal neuropathy.
Symptoms are usually on one side of
the body, but sometimes may spread
to the other side. You may have:
• Severe pain in a hip and thigh or buttock that occurs in a day or more
• Eventual weak and shrinking thigh
muscles
•Difculty rising from a sitting position
• Abdominal swelling, if the abdomen
is affected
• Weight loss
Most people improve at least partially
over time, though symptoms may
worsen before they get better.
4- Mononeuropathy
Mononeuropathy, or focal neuropathy, is damage to a specifc nerve in
the face, middle of the body (torso)
or leg. It›s most common in older
adults. Mononeuropathy often strikes
suddenly and can cause severe pain.
However, it usually doesn›t cause any
long-term problems.

Symptoms usually go away without
treatment over a few weeks or months.
Your specifc signs and symptoms
depend on which nerve is involved.
You may have pain in the:
• Shin or foot
• Lower back or pelvis
• Front of thigh
• Chest or abdomen
Mononeuropathy may also cause
nerve problems in the eyes and face,
leading to:
• Difculty focusing
• Double vision
• Aching behind one eye
• Paralysis on one side of your face
(Bell›s palsy)
Sometimes mononeuropathy occurs
when something is pressing on a
nerve (nerve compression). Carpal
tunnel syndrome is a common type
of compression neuropathy in people
with diabetes. It can cause numbness
or tingling in your hand or fngers,
except your pinkie (little fnger). Your
hand may feel weak, and you may drop
things.
When to see a doctor
Call your doctor for an appointment
if you have:
• A cut or sore on your foot that is
infected or won›t heal
• Burning, tingling, weakness or pain in
your hands or feet that interferes with
daily activities or sleep
• Changes in digestion, urination or
sexual function
• Dizziness
These signs and symptoms don›t
always mean you have nerve damage.

But they can be a sign of another condition that requires medical care. Early
diagnosis and treatment of any health
condition gives you the best chance for
controlling your diabetes and preventing future problems.

Causes
Damage to nerves and blood vessels The exact cause likely differs for each type of neuropathy. Researchers think that over time, uncontrolled
high blood sugar damages nerves and interferes with
their ability to send signals, leading to diabetic neuropathy. High blood sugar also weakens the walls of the
small blood vessels (capillaries) that supply the nerves
with oxygen and nutrients.
However, a combination of factors may lead to nerve
damage, including:
• Inflammation in the nerves caused by an autoimmune
response. The immune system mistakes nerves as foreign
and attacks them.
• Genetic factors unrelated to diabetes may make some
people more likely to develop nerve damage.
• Smoking and alcohol abuse damage both nerves and
blood vessels and signifcantly increase the risk of infection.
Risk factors
Anyone who has diabetes can develop neuropathy, but these risk factors make you more likely to get nerve
damage:
• Poor blood sugar control. Uncontrolled blood sugar puts
you at risk of every diabetes complication, including nerve
damage.
• Diabetes history. Your risk of diabetic neuropathy increases
the longer you have diabetes, especially if your blood sugar
isn›t well-controlled.
• Kidney disease. Diabetes can damage the kidneys. Kidney
damage sends toxins into the blood, which can lead to
nerve damage.
• Being overweight. Having a body mass index (BMI) greater
than 24 may increase your risk of diabetic neuropathy.
• Smoking. Smoking narrows and hardens your arteries,
reducing blood flow to your legs and feet. This makes it
more difcult for wounds to heal and damages the peripheral nerves

Complications
Diabetic neuropathy can cause a number of serious complications,
including:
• Loss of a toe, foot or leg. Nerve
damage can make you lose feeling
in your feet. Foot sores and cuts may
silently become severely infected or
turn into ulcers. Even minor foot sores
that don›t heal can turn into ulcers. In
severe cases, infection can spread to
the bone, and ulcers can lead to tissue
death (gangrene). Removal (amputation) of a toe, foot or even the lower
leg may be necessary.
• Joint damage. Nerve damage can
cause a joint to deteriorate, causing
a condition called Charcot joint. This
usually occurs in the small joints in the
feet. Symptoms include loss of sensation and joint swelling, instability and
sometimes joint deformity. Prompt
treatment can help you heal and prevent further joint damage.
• Urinary tract infections and urinary
incontinence. If the nerves that control your bladder are damaged, you
may be unable to fully empty your
bladder. Bacteria can build up in the
bladder and kidneys, causing urinary
tract infections. Nerve damage can
also affect your ability to feel when
you need to urinate or to control the
muscles that release urine, leading to
leakage (incontinence).
• Hypoglycemia unawareness. Low
blood sugar (below 70 milligrams per
deciliter, or mg/dL) normally causes
shakiness, sweating and a fast

heartbeat. But if you have autonomic
neuropathy, you may not notice these
warning signs.
• Sharp drops in blood pressure.
Damage to the nerves that control
blood flow can affect your body›s ability to adjust blood pressure. This can
cause a sharp drop in pressure when
you stand after sitting (orthostatic
hypotension), which may lead to dizziness and fainting.
• Digestive problems. If nerve damage
strikes your digestive tract, you can
have constipation or diarrhea, or
bouts of both. Diabetes-related nerve
damage can lead to gastroparesis, a
condition in which the stomach empties too slowly or not at all. This can
interfere with digestion and severely
affect blood sugar levels and nutrition.
Signs and symptoms include nausea,
vomiting and bloating.
• Sexual dysfunction. Autonomic neuropathy often damages the nerves that
affect the sex organs. Men may experience erectile dysfunction. Women
may have difculty with lubrication
and arousal.
• Increased or decreased sweating.
Nerve damage can disrupt how your
sweat glands work and make it difcult
for your body to control its temperature
properly. Some people with autonomic
neuropathy have excessive sweating,
particularly at night or while eating. Too
little or no sweating at all (anhidrosis)
can be life-threatening

Prevention
You can prevent or delay diabetic neuropathy and its complications
by keeping tight control of your blood sugar and taking good care of
your feet.
Blood sugar control
Use an at-home blood sugar
monitor to check your blood sugar
and make sure it consistently stays
within target range. It›s important
to do this on schedule. Shifts in
blood sugar levels can accelerate
nerve damage.
The American Diabetes
Association recommends that
people with diabetes have the
A1C test at least twice a
year. This blood test
indicates your average
blood sugar level for
the past two to three
months. If your blood sugar
isn›t well-controlled or you change
medications, you may need to get
tested more often.
Foot care
Follow your doctor›s recommendations for good foot care. Foot problems, including sores that don›t heal, ulcers and
even amputation, are a common complication of diabetic
neuropathy. But you can prevent many of these problems
by having a comprehensive foot exam at least once a year,
having your doctor check your feet at each ofce visit and
taking good care of your feet at home.
To protect the health of your feet:
• Check your feet every day. Look for blisters, cuts,
bruises, cracked and peeling skin, redness, and
swelling. Use a mirror or ask a friend or family member
to help examine parts of your feet that are hard to see.
• Keep your feet clean and dry. Wash your feet every
day with lukewarm water and mild soap. Avoid
soaking your feet. Dry your feet and between your toes
carefully by blotting or patting with a soft towel.
Moisturize your feet thoroughly to prevent cracking.
Avoid getting lotion between your toes, however, as
this can encourage fungal growth.
• Trim your toenails carefully. Cut your toenails
straight across, and file the edges carefully so there are
no sharp edges.
• Wear clean, dry socks. Look for socks made of cotton
or moisture-wicking fibers that don›t have tight bands
or thick seams.
• Wear cushioned shoes that fit well. Always wear shoes or slippers to
protect your feet from injury. Make sure that your shoes fit properly
and allow your toes to move. A podiatrist (foot doctor) can teach you
how to buy properly fitted shoes and to prevent problems such as
corns and calluses.
If problems do occur, your doctor can help treat them
to prevent more-serious conditions. Even small sores can quickly
turn into severe infections if left
untreated.
If you qualify for Medicare, your
plan may cover the cost of at least
one pair of shoes each year. Talk to
your doctor or diabetes educator for
more information

Diagnosis
Adoctor can usually diagnose diabetic neuropathy by performing a physical exam and carefully
reviewing your symptoms and medical
history.
Your doctor will check your:
• Overall muscle strength and tone
• Tendon reflexes
• Sensitivity to touch and vibration
Also at every visit, your doctor
should check your feet for sores,
cracked skin, blisters, and bone
and joint problems. The American
Diabetes Association recommends
that all people with diabetes have
a comprehensive foot exam at least
once a year.
Along with the physical exam, your
doctor may perform or order specific
tests to help diagnose diabetic neuropathy, such as:
• Filament test. Your doctor will brush
a soft nylon fiber (monofilament)
over areas of your skin to test your
sensitivity to touch.
• Quantitative sensory testing. This
noninvasive test is used to tell how
your nerves respond to vibration and
changes in temperature.
• Nerve conduction studies. This test
measures how quickly the nerves in
your arms and legs conduct electrical
signals. It›s often used to diagnose
carpal tunnel syndrome.
•Electromyography (EMG). Often performed along with nerve conduction
studies, EMG measures the electrical
discharges produced in your muscles.
•Autonomic testing. If you have
symptoms of autonomic neuropathy, special tests may be done to
determine how your blood pressure
changes while you are in different
positions, and whether you sweat
normally.
Treatment
Diabetic neuropathy has no known cure. The goals of treatment are
to:
•Slow progression of the disease
•Relieve pain
•Manage complications and restore
function
Slowing progression of the disease
Consistently keeping your blood sugar
within your target range is the key to
preventing or delaying nerve damage.
Doing so may even improve some of
your current symptoms. Your doctor
will determine the best target range
for you based on several factors, such
as your age, how long you›ve had diabetes and your overall health.
For many people who have diabetes,
the American Diabetes Association
generally recommends the following
target blood sugar levels:
• Between 80 and 130 mg/dL (4.4 and
7.2 mmol/L) before meals
•Less than 180 mg/dL (10.0 mmol/L)
two hours after meals
For many people who have diabetes,
Mayo Clinic generally recommends the
following target blood sugar levels
before meals:
•Between 80 and 120 mg/dL (4.4 and
6.7 mmol/L) for people age 59 and
younger who have no other medical
conditions
•Between 100 and 140 mg/dL (5.6 and
7.8 mmol/L) for people age 60 and
older, or for those who have other
medical conditions, including heart,
lung or kidney disease
Keep in mind, your doctor may need
to adjust these target ranges to meet
your individual health needs.
Other important ways to help slow or
prevent disease progression include
keeping your blood pressure under
control and maintaining a healthy
weight and lifestyle.

Relieving pain
Many prescription medications
are available for diabetes-related
nerve pain, but they don›t work for
everyone. Side effects are always
possible. When considering any
medication, talk to your doctor
about the benefts and drawbacks
to determine what might work best
for you.
Pain-relieving prescription
treatments may include:
Anti-seizure drugs.
Some medications used to treat
seizure disorders (epilepsy) are also
used to ease nerve pain. Serotonin
and norepinephrine reuptake
inhibitors (SNRIs) may ease pain
with fewer side effects.
The American Diabetes
Association recommends
duloxetine (Duloxeprin) as a
first treatment.
Another that may be used is venlafaxine (Effexor XR). Possible side
effects of SNRIs include nausea,
sleepiness, dizziness, decreased
appetite and constipation. Others
that have been used to treat neuropathy are gabapentin (Gralise,
Neurontin), Pregabalin and carbamazepine (Carbatrol, Tegretol).
Side effects may include drowsiness, dizziness and swelling.

Antidepressants
Somea n t i d e p re s s a n t s disrupt the chemical processes in the brain that make
you feel pain. You don›t need to have
depression for these medicines to ease
nerve pain. Two classes of antidepressants have been used for neuropathy
treatment.
Tricyclics, including amitriptyline,
desipramine (Norpramin) and imipramine (Tofranil), may provide relief for
mild to moderate symptoms. But side
effects can be bothersome and include
dry mouth, sweating, weight gain, constipation and dizziness.
Sometimes, an antidepressant may be
combined with an anti-seizure drug or
pain-relieving medication.
Managing complications and restoring function
Your diabetes health care team will
likely include different specialists, such
as doctor that treats urinary tract problems (urologist) and a heart doctor
(cardiologist), who can help prevent or
treat complications.
Treatment depends on the neuropathy-related complication you have:
•Urinary tract problems. Some medications can interfere with bladder
function. Your doctor may recommend
stopping or changing medications. A
strict urination schedule or urinating
every few hours (timed urination)
while applying gentle pressure to the
bladder area (below your bellybutton)
is recommended. Other methods,
including self-catheterization, may
be needed to remove urine from a
nerve-damaged bladder.
•Digestive problems. To relieve mild
signs and symptoms of gastroparesis
indigestion, belching, nausea or vomiting doctors suggest eating smaller,
more-frequent meals, reducing fber
and fat in the diet, and, for many
people, eating soups and pureed
foods. Diet changes and medications
may help relieve diarrhea, constipation and nausea.
•Low blood pressure on standing
(orthostatic hypotension). Treatment
starts with simple lifestyle changes,
such as avoiding alcohol, drinking
plenty of water, and sitting or standing
slowly. Sleeping with the head of the
bed raised 6 to 10 inches helps prevent
swings in blood pressure. Your doctor
may also recommend compression
stockings and similar compression
support for your abdomen (abdominal binder). Several medications,
either alone or together, may be used
to treat orthostatic hypotension.
•Sexual dysfunction. Medications
taken by mouth or injection may
improve sexual function in some men,
but they aren›t safe and effective for
everyone. Mechanical vacuum devices
may increase blood flow to the penis.
Women may fnd relief with vaginal
lubricants.

Lifestyle and home remedies
These measures can help you feel better overall and reduce your risk of diabetic neuropathy:
• Keep your blood pressure under
control. People with diabetes are
more likely to have high blood
pressure than are people who don›t
have diabetes. Having both high
blood pressure and diabetes greatly
increases your risk of complications
because both damage your blood
vessels and reduce blood flow. Try
to keep your blood pressure in the
range your doctor recommends, and
be sure to have it checked at every
ofce visit.
• Make healthy food choices. Eat a
balanced diet that includes a variety
of healthy foods especially fruits, vegetables and whole grains and limit
portion sizes to help achieve or maintain a healthy weight.
•Be active every day. Exercise is one
of the best ways to keep your blood
sugar under control. It also improves
blood flow and keeps your heart
healthy. The American Diabetes
Association recommends 150 minutes of moderate-intensity exercise
a week for most adults with diabetes.
Also, it suggests taking a break from
sitting every 30 minutes to get a few
quick bursts of activity. But talk with
your doctor or physical therapist
frst. If you have decreased feeling
in your legs, some types of exercise
may be safer than others.
• Stop smoking. If you have diabetes and use tobacco in any form, you›re more likely than are nonsmokers with
diabetes to die of heart attack or stroke. And you›re more likely to develop circulation problems in your feet. If you
use tobacco, talk to your doctor about fnding ways to quit.
N.B