Diabetes is a disorder of sugar metabolism which affects almost all organ systems of the human body. In humans we can divide our nervous system in to central and peripheral nervous systems. Central nervous system is our brain, and cranial nerves. Peripheral nervous system is the other all peripheral nerves.
Peripheral nervous system can be divided into few sub categories according to the function of nerves as sensory (sensations), motor (actions) and autonomic (actions of unaware). Neuropathy is a medical term for any disease in nerves. When the disease is caused by diabetes it is called as diabetic neuropathy. Diabetes affects almost all nerves in the body but actions are prominent in peripheral nervous system. Therefore diabetic peripheral neuropathy can be sensory, motor or autonomic. Each of these has its own signs and symptoms.
Medical definition of diabetic peripheral neuropathy is the presence of symptoms and/or signs of peripheral nerve dysfunction in people with diabetes, after exclusion of other causes of neuropathy. Neuropathies are the most common complication of uncontrolled diabetes or long standing diabetes. With inadequate glycemic control nearly 75% of all patients can evolve neuropathies in 2 years’ time as well in type 1 as in type 2 diabetes mellitus.
Main symptom of diabetic neuropathy is altered sensation of the skin. Most of the times it is reduced sensation but in few instances the sensation may be come painful. Due to reduced sensation there can be secondary signs and symptoms such as foot and skin ulcers, falls, burns, cuts and secondary infections which may even lead to amputation of limbs or death.
Clinically diabetic peripheral neuropathy can be divided into few stages according to the signs and symptoms.
- Chronic painful diabetic peripheral neuropathy
- Burning, shooting, stabbing pains associated with pins and needle sensations
- Pain increased at night
- Absent sensation to several modalities such as temperature, touch, pain
- Reduced or absent reflexes
- Acute painful diabetic peripheral neuropathy
- Severe symptoms as chronic painful
- May be associated with start of the insulin in poorly controlled diabetics
- Painless with complete or partial sensory loss due to diabetic peripheral neuropathy
- Severe numbness injuries
- Reduced temperature sensations
- Absent reflexes
- Late complications of diabetic peripheral neuropathy
- Foot ulcers and deformities
- Non-traumatic amputation
- Dead limbs
Generally 30% of diabetics have peripheral neuropathies at the time of diagnosis of diabetes. In USA it is estimated that 3 – 5% of diabetics develop neuropathy associated severe complications such as amputations and even death. Worldwide 40 – 50% of non-traumatic amputations are due to diabetic neuropathies.
Neuropathy is assessed clinically. Ideally should be done annually. Main reason is to detect the prevailing neuropathy and identify risk factors and alarm signs of developing the neuropathy in the near future.
A detailed history should be a part of risk assessment of the diabetes. This should include the following:
- Type of diabetes
- Alcohol and smoking status
- Leisure activities
- Use of foot wear or special footwear
- Home circumstances
- Social support
- Access to health care facilities
- Knowledge about diabetes and neuropathy
Examination of the feet
Remove your shoes and socks then wash the feet with lukewarm water and wipe with a clean towel. The feet should be inspected for the following:
- Skin – color, consistency ,thickness, dryness , cracks, sweat
- Interdigital areas – fungal infections, ulcers
- Foot arches
- Sensation to pain, touch, temperature
- Should palpate for sensory and pulses such as dorsalis pedis artery and posterior tibial artery.
- Check capillary refill time (CRFT)
- Nails for their color and consistency
Neurological assessment of the foot
This is the most important test which should be done at least every 2 months. It is a very simple test which needs only a 10g monofilament and a good light source. Feet is palpated with the monofilament and assess the sensation by the patient. If patient can’t feel it then the test is positive for diabetic peripheral neuropathy.
Other types of diabetic peripheral neuropathy
Autonomic diabetic peripheral neuropathy
When autonomic nerves are affected by the diabetes it is called autonomic diabetic peripheral neuropathy. Autonomic nerves supply all of the internal organs such as heart, lungs, gut, genital organs and other internal organs. When there is autonomic diabetic peripheral neuropathy the functions of these organs are compromised and can result in various disorders specific to each organ.
- Heart – arrhythmias, palpitations and increased fatigue
- Gut – ileus, gut motion dysfunctions
Motor diabetic peripheral neuropathy
Motor means “Actions”. Actions in our body are mainly carried out by musculoskeletal system of the body. Motor nerves supply the musculoskeletal system. Each muscle in the body has its own nerve. When the motor diabetic peripheral neuropathy affects the nerve the muscle also gets affected. It results in reduced function and the bulk of muscle fibers.
Diabetic peripheral neuropathy is the most common complication of diabetes mellitus. It can lead to various complications such as ulcers, amputations and even death. Early identification and early treatments reduces the risks.