The most common form of diabetic neuropathy is distal symmetric polyneuropathy. It is called distal because it typically begins in the lower legs with painful paresthesias, or tingling, which progresses over time to numbness. It is called symmetric because both sides of the body are affected equally. And it is called polyneuropathy because feet, calves, and then hands are affected in a stocking-glove distribution. In other words, tingling occurs in an area of the hands and feet as if you were wearing gloves and stockings.
Diabetes is the most common cause of stocking-glove neuropathy, but there are other causes that your doctor will need to rule out, such as excessive alcohol use, hypothyroidism, renal failure, and folic acid or vitamin B12 deficiencies.
The first complication of distal neuropathy is pain, which can be debilitating, making it difficult to walk or sleep. Although some patients develop chronic pain, for most people, the pain remits within 16 to 24 months. Neuropathy also weakens the small muscles of the foot, causing the toes to curl. This condition is called a claw-foot deformity. As your weight shifts to the ball of the foot, abnormal calluses can form.
Another complication is numbness. It is less noticeable than pain, but often more dangerous, as unnoticed numbness can lead to unnoticed injuries that can progress to skin ulceration. Acute ulcerations caused by silent trauma and chronic ulcerations caused by foot deformities can become infected. If not treated promptly, further tissue damage can follow.
Because of the underlying neuropathy and sometimes poor vascular supply, infections can be slow to heal, and in some cases, they may not heal at all. Amputation then becomes the sad outcome of diabetic neuropathy. Half of all amputations in the United States result from diabetic complications.
Neuropathy Risk Factors
Two major factors determine your risk for neuropathy: The level of your average blood sugar and the length of time you have had diabetes.
Your doctor can determine your average blood sugar by checking a hemoglobin A1C, which allows the doctor to see if your blood sugars have been controlled during the last several weeks. This test is more accurate than a random blood sugar. The Diabetes Control and Complications trial demonstrated that tight blood-glucose control can decrease the risk of developing neuropathy by 60 percent and can delay the progression of it. Neuropathy equally affects patients with type 1 diabetes and type 2 diabetes.
The most important means of preventing and treating neuropathy is to control your sugar level. Tight glucose control is attained when the blood-sugar level after fasting is less than 120 mg/dl; two hours after eating, it is less than 160 mg/dl; the average blood-sugar level is less than 150mg/dl; and hemoglobin A1C is less than seven percent when checked with a blood glucose monitor.
In addition to tight glucose control, there are two other components in the treatment of diabetic polyneuropathy: good foot hygiene and attention to neuropathic pain.
Sometimes, no matter how well you control your blood sugar, neuropathy still develops. It becomes a team effort between you and your doctor to prevent the complications of neuropathy, which are mainly ulceration, infection, and amputation. Good foot hygiene is an essential component of management of the diabetic foot. If you can prevent trauma to your feet, many of the complications can be prevented.