Diabetic Nerve Damage: Neuropathy

Guest Post from David Mapletoft, Diabetes Educator

Diabetic neuropathy is a type of nerve damage that can occur if you have diabetes. High blood glucose can injure nerve fibers throughout your body, but 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 extremities to problems with your digestive system, urinary tract, blood vessels and heart. For some people, these symptoms are mild; for others, diabetic neuropathy can be painful, disabling and even fatal.

Diabetic neuropathy is a common serious complication of diabetes. Yet you can often prevent diabetic neuropathy or slow its progress with tight blood glucose management, and a healthy lifestyle.

Clinical context

Pain and paraesthesia are common peripheral neuropathic symptoms, and if the autonomic nervous system is involved, gastrointestinal, bladder and sexual problems arise.

Diabetic neuropathic complications increase the burden of self-care and overall management.

The clinical focus is on prevention via good glycaemic control, and early recognition facilitated by good history and routine sensory testing.

New modalities are arriving to assist in the management of diabetic neuropathies.

Before any treatment is instigated, exclusion of non-diabetic causes of neuropathy is suggested. This includes assessment for vitamin B12 deficiency, hypothyroidism, renal disease and review of neurotoxic drugs including excessive alcohol consumption.

Autonomic neuropathy

Autonomic neuropathy may result in:

• orthostatic hypotension  (also called postural hypotension, is a form of low blood pressure that can cause dizziness. It happens when the blood vessels do not constrict (tighten) as you stand up, which makes you feel dizzy) with >20 mmHg drop
• impaired and unpredictable gastric emptying (gastroparesis), which can cause a person’s blood glucose levels to be erratic and difficult to control. Pro-kinetic agents such as metoclopramide, domperidone or erythromycin may improve symptoms
• diarrhoea
• delayed/incomplete bladder emptying
• erectile dysfunction and retrograde ejaculation in males
• reduced vaginal lubrication with arousal in women
• loss of cardiac pain, ‘silent’ ischaemia or infarction
• sudden, unexpected cardiorespiratory arrest especially under anaesthetic or treatment with respiratory depressant medications
• difficulty recognising hypoglycaemia
• unexplained ankle oedema.

Cardiovascular autonomic neuropathy should be suspected by resting tachycardia (>100 bpm) or orthostatic reduction in BP (a fall in SBP >20 mmHg on standing without an appropriate heart rate response). This applies to people not currently on antihypertensive agents that may cause variations in BP responsiveness such as beta blockers. It is associated with increased cardiac event rates.

Diagnosis 

The diagnosis of diabetic neuropathy may include:

• taking a medical history for symptoms typical of neuropathy
• checking your feet and legs for responses to stimuli such as temperature, light touch, pain, movement and vibration
• checking the reflexes at your ankles and knees
• tests to exclude other possible causes of neuropathy (such as low vitamin B₁ or thiamine levels).

Treatment

Damaged nerves cannot be repaired. However, the risk of further complications in the feet can be reduced by:

• vigilance – regular inspection of the feet for early signs of trouble or potential problem areas (such as breaks in skin, signs of infection or deformity
• getting help at the first sign of trouble – early treatment of foot ulcers gives the best chance that they will heal
• good foot and nail hygiene
• choosing appropriate socks and shoes properly fitted to the shape of your foot
• avoiding activities that may injure the feet. Check shoes for stones, sticks and other foreign objects that might hurt your feet every time before putting your shoes on.

A referral to a podiatrist may be appropriate for assessment and ongoing preventive management of foot complications.

Treatment for painful neuropathy

Appropriate pain management can significantly improve the lives of people with diabetes and painful neuropathy. A number of different medications are available, which produce comparable effects.

Most people would begin with one of either:

• serotonin-norepinephrine reuptake inhibitors (such as venlafaxine, duloxetine)
• tricyclics antidepressants (such as amityptiline)
• anti-epileptics (such as gabapentin, pregabalin).

If one type fails to provide the response required, it is usual to switch to or add another. If all three agents alone or in combination fail, then opioid analgesics and tramadol may be used as second-line treatments.

Prevention of diabetic neuropathy

Be guided by your doctor, but general suggestions to reduce the risk of diabetic neuropathy include:

• Maintain blood glucose levels within the target ranges.
• Exercise regularly.
• Maintain a healthy weight for your height.
• Stop smoking.
• Reduce your blood pressure and lipid (fat) levels through diet and lifestyle changes, and medication where appropriate
• Consult your doctor promptly if you have symptoms including pain, numbness or tingling in your hands or feet.
• Have your feet checked at least yearly by your doctor, podiatrist or diabetes educator, or more often if you have signs of problems with your feet or other complications of your diabetes.

 

Although, potential health complications due to diabetes may happen; don not live in fear, by watching the amount and types of food you eat, exercising, and taking any necessary medications, you may be able to prevent short and long-term diabetes complications.

• Keeping blood glucose close to normal can help prevent the long-term complications of diabetes.
• Manage high blood pressure.
• Monitor your blood sugar level and A1c.
• Have regular reviews with your diabetes care team.

Talk to your health care professional team: ask questions and get answers that you understand….. prevention is better than a decreased quality of life. 

David, Diabetes Educator