Grandma: Dr. Pond, I thought that you could tell my grandson about the complication that affects the feet.
Diabetic neuropathy- a diabetic disease of the nerves
Nerves- a bundle of nerve fibers outside the central nervous system that connect the brain and spinal cord with other parts of the body. They carry all sensation from the body to the brain and from the brain to the body
Diffuse neuropathy- a disease of the nerves that affects many parts of the body
Focal neuropathy- a disease of the nerves that affects a single nerve and part of the body
Dr. Pond: Oh! Yes, that would be diabetic neuropathy which is a nerve disease that is caused by diabetes. The nerves carry all sensation from the body to the brain and carry all information from the brain to the muscles. Nerve damage has far-reaching implications. It can be divided into two categories: diffuse neuropathy which affects many parts of the body and focal neuropathy which affects a single nerve and part of the body. Diffuse neuropathy is the most common.
Peripheral Nerve at 600x
Dustin: What causes diabetic neuropathy?
Dr. Pond: Unfortunately, the causes of neuropathy are not fully understood. However, research is being conducted to understand how diabetes affects the nerves and to find better treatments. One factor that is found to contribute to diabetic neuropathy is high blood glucose levels. High levels can cause chemical changes in the nerves that prevent the nerves from transmitting signals to different parts of the body. It also damages blood vessels that carry oxygen and nutrients to the nerves.
Dustin: So how exactly does high blood glucose levels affect the nerves?
Dr. Pond: The exact mechanism explaining how high blood glucose levels affect the nerves is not known. However, researchers have found that high glucose levels disturb metabolic pathways in the nerves which can lead to a build-up of a sugar known as sorbitol and, at the same time, decrease a substance known as myoinositol.
Grandma: Oh! So that's why it's so important to control high blood glucose levels.
Dr. Pond: Yes, it's very important.
Dustin: So is that the only cause of diabetic neuropathy?
Dr. Pond: No, the other factors that are caused by diabetes are disease of the blood vessels, high lipids or fat levels. Genetics and the environment may also contribute to diabetic neuropathy.
Dustin: Which one of the two types of diabetic neuropathy causes problems with the feet?
Dr. Pond: That is diffuse neuropathy. This type of neuropathy can be divided into two categories. The first category is peripheral neuropathy which damages the nerves of the limbs, such as the hands and the feet. The damage can lead to a loss of reflexes, a loss of sensation and maybe even a weakening of the muscles, but the feet are mainly affected first.
Peripheral neuropathy- nerve damage of the limbs, such as the hands and the feet
Ulcers-an open sore or lesion of the skin or mucous membrane accompanied by sloughing of inflamed necrotic tissue
Dustin: Are those the only effects that the peripheral neuropathy could have on the feet?
Dr. Pond: No, it can also cause the foot to become shorter and wider or it can cause foot ulcers which are open wounds that may appear as pressure is applied to less protected parts of the foot. Since there is no sensation, these progress without any discomfort. Also, diabetic vessel disease causes a decreased blood supply and the healing of the ulcers is slowed. If the ulcers are not treated soon enough, they become infected and amputation may be required.
Dustin: How can my mom prevent amputations from happening?
Dr. Pond: Well, she can practice proper foot care habits, in order to prevent ulcers and other injuries that can lead to amputations.
Dustin: Dr. Pond, that is the other type of diffuse neuropathy? Just in case my mom ever develops any of those symptoms.
Autonomic neuropathy- damage of the nerves that control the heart and other internal organs
Dr. Pond: The other type of diffuse neuropathy is known as autonomic neuropathy and is caused by damage to nerves that control the heart and other internal organs.
Dustin: What other internal organs does it affect?
Dr. Pond: There may be a loss of control of urination because the nerves may be prevented from enabling the muscles to empty the bladder.
Dustin: Wow, I never knew that was caused by diabetic neuropathy. What else can it affect that I probably don't know about?
Dr. Pond: Some people don't like to talk about this aspect of it or very few people even know that diabetic neuropathy can cause this. But sexual response also damages nerves that are necessary to "sense" stimulation and to cause vessel response.
Dustin: Doctor, tell me what else autonomic neuropathy can do.
Esophagus- a muscular canal extending form the pharynx to the stomach. This is essential for carrying swallowed foods and liquids from the mouth to the stomach
Gastric stasis- a slow emptying of the stomach
Cardiovascular system- contains the heart and blood vessels
Hypoglycemia- deficiency of sugar in the blood
Carpal tunnel syndrome- nerve damage that can lead to weakness, tingling, numbness and possibly muscle weakness in the hands
Dr. Pond: It can affect digestion, since the muscles of the gut are poorly controlled. The nerve damage can make it difficult to swallow if the esophagus is affected and it can damage the large intestine which can lead to constipation or diarrhea. Nerve damage can also cause a slow emptying of the stomach known as gastric stasis. Autonomic neuropathy also may affect the cardiovascular system which may interfere with nerves that regulate blood pressure and heart rate. It may also affect a person's perception of pain from heart attacks. It can also slow a diabetic's response to an insulin reaction because of the body's slow response to low blood sugar or hypoglycemia. Lastly, autonomic neuropathy may affect the nerves that regulate sweating which can make it very difficult to regulate body temperature.
Dustin: Doctor, that sure sounds like a lot of problems that can happen if the nerves are damaged.
Dr. Pond: Yes, those are pretty serious problems, but the second type of neuropathy that occurs less often is focal neuropathy and although it is not as common, it can be very painful. Focal neuropathy does improve over a period of time with no long-term damage. The most common form of focal neuropathy is the carpal tunnel syndrome which is a nerve damage in the wrist that can lead to weakness, tingling, numbness and possibly muscle weakness in the hands.
Dustin: This diabetic neuropathy is serious stuff. Well, how come my mom doesn't have any of the symptoms of diabetic neuropathy?
Dr. Pond: That's because neuropathy occurs over a period of years, and, therefore, mild cases of diabetic neuropathy could go unnoticed for a long time.
Dustin: So how many patients with diabetes actually have neuropathy?
Dr. Pond: Statistics have shown that 60 percent of diabetic patients have a form of neuropathy and 30 to 40 percent of the patients with diabetes have symptoms of neuropathy.
Dustin: How do you treat neuropathy once a patient is known to have it?
Dr. Pond: The treatment of diabetic neuropathy is focused on the prevention of further tissue damage and discomfort. This is done by keeping control of blood sugar, by caring for the feet, and by taking numerous medications. Diagnosis and treatments can be given by a doctor based on the patient's symptoms and on a physical exam.
Grandma: Well that was very interesting. Now I'll know what is happening to me if I get any of the aspects of diabetic neuropathy that you talked about.
Dustin: And I'll better understand what is happening to my mom, so I can help her through it.
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