Diabetic neuropathy

What is diabetic neuropathy?

A disease of diabetes mellitus and the dysregulated blood sugar level in this context can result in a wide range of consequential damage that can affect practically all parts of the body and systems. A distinction is made between short-term and long-term secondary diseases. The latter includes damage to nerves (neuropathy), which is called diabetic neuropathy when its cause is taken into account. About every third diabetic patient develops diabetic neuropathy. If only a single nerve is affected, it is called diabetic mononeuropathy, if several nerves are damaged, it is called diabetic polyneuropathy. The neuropathy mostly affects so-called peripheral nerves, which are responsible for the movement of muscles and for conveying skin and sensory impressions. On the other hand, diabetic autonomic neuropathy is a special case, in which internal organ or sensory functions are impaired (e.g. cardiac arrhythmia, intestinal paralysis, bladder weakness or erectile dysfunction.

Concomitant symptoms of diabetic neuropathy

Diabetic neuropathy can manifest itself in many different ways, depending on which nerves are affected. Usually this happens in the form of nerve-related abnormal sensations ("paresthesia"), which means that those affected feel tingling sensations or a burning sensation. Occasionally, so-called neuropathic pain also occurs. Those affected usually describe this as sudden, shooting pain, often in combination with burning or tingling sensations. Often this pain worsens at night and regularly deprives those affected of their sleep. In rare cases, paralysis or numbness can also occur in individual muscles or areas of the skin.

Also read: Burning in the fingers

Even if there is theoretically a broad spectrum of possible symptoms of diabetic neuropathy, this disease often manifests itself according to a certain scheme: First of all, the feet and legs are affected, in which painful sensations in the form of tingling and burning or a disturbed coldness are felt again and again - and heat perception are noticed. Over time, recurring shooting pains (neuropathic pain) join in and the symptoms spread to the hands and arms. If no appropriate therapy is initiated, paralysis or numbness in the extremities can occur.

The reduced sensitivity of the skin of the feet and legs can also lead to a complicated secondary disease: the diabetic foot. This initially leads to a strange misalignment of the foot. This is because weight is shifted in unusual ways in response to the damaged sensory nerves in the foot. As the disease progresses, blisters, abrasions and other wounds appear without the person concerned being able to remember a cause. The reason for this is diabetic neuropathy: Due to the reduction in skin sensitivity, the foot is repositioned less often and the weight is less frequently shifted to different parts of the foot. So over a longer period of time, great pressure is exerted on the same area of ​​the foot, which can lead to skin irritation and, over time, to open wounds.

The symptoms of diabetic autonomic neuropathy must be considered independently of this. These include occasional racing or tripping of the heart, decreased or increased sweating, diarrhea and constipation, regular bloating with belching and erectile dysfunction.

Is Diabetic Neuropathy Curable?

Although diabetic neuropathy is not really curable, the course of the disease can under certain circumstances be positively influenced to the extent that the person concerned no longer feels any associated symptoms. However, this is only possible if the neuropathy is recognized very quickly and treated promptly. A disciplined and effective treatment of the underlying diabetes mellitus is just as important. In more advanced stages, even with these measures, complete freedom from symptoms may not be possible, but at least a clear improvement can be achieved. These aspects make it clear how important it is to consistently follow diabetes therapy and to have regular check-ups.

What is the course of diabetic neuropathy?

The course of diabetic neuropathy is very variable and highly dependent on the quality of the blood sugar control. If this is done consistently and in a disciplined manner, the progression of nerve damage can often be slowed down or even stopped completely and the symptoms reduced to a minimum. Some sufferers even become completely symptom-free under diabetes and neuropathy therapy. As a rule, however, a slow progression of the neuropathy and consequently also of the associated symptoms can be observed. It is all the more essential to adhere to the recommended intervals for check-ups! To avoid the development of a diabetic foot syndrome, you should regularly check your feet (especially the soles of the feet and other pressure points such as toes and heels) for skin irritations or even open areas.

Treatment of diabetic neuropathy

Since nerve damage once it has occurred cannot be reversed, the focus is on preventing the damage from progressing and minimizing the symptoms. The best and most effective measure for the prevention and at the same time also for the treatment of diabetic neuropathy is the optimal adjustment of the blood sugar level. Avoiding alcohol and nicotine also has a positive influence on the course of the disease. There are various therapy options to curb paresthesia, functional failures and pain, the choice of which should be made in consultation with the treating physician (usually family doctor, diabetologist and neurologist). In addition to drug treatment (see below), there are also physiotherapy (especially for symptoms of paralysis), electrical nerve stimulation (TENS) or cold and heat treatments.

Read more about: TENS electrotherapy

What drugs are used for diabetic neuropathy?

The main drugs used for diabetic neuropathy are the diabetes drugs. Only with optimal and consistent blood sugar control can the progression of diabetic neuropathy be sustained and the accompanying symptoms dampened or even completely eliminated. Depending on the type of diabetes, insulin syringes and / or medicines that can be taken by mouth are used. These are discussed in more detail in the relevant article on diabetes treatment.

You can find more information about the diabetes medication at: Therapy of diabetes

Tricyclic antidepressants play a central role in the treatment of abnormal sensations and neuropathic pain. The name comes from the fact that these substances were initially used to treat depression, and only later was their positive effect on nerve pain discovered. The most common representatives of this drug class are amitriptyline, imipramine and nortryptiline. If secondary illnesses speak against their use or if their use has caused excessive side effects, carbamazepine can be prescribed as an alternative. Another alternative is to apply capsaicin cream to the affected areas, but many of those affected do not tolerate it too well. Current research is concerned with the development of substances that not only treat pain, but could also influence structural damage to the nerve. So far, however, a positive effect has only been proven for intravenous (i.e. administered by infusion) administration of α-lipoic acid.

Duration of diabetic neuropathy

Since diabetic neuropathy, according to the current state of affairs, has to be classified as incurable, but in the best case controllable, it will unfortunately accompany those affected for a lifetime. After optimal blood sugar control and the initiation of pain therapy, however, significant improvements in symptoms can often be achieved within a few weeks. Often, however, there is a cyclical increase and decrease in symptoms over time, which then requires a corresponding flexibility in the drug dosage.

Diagnosis of diabetic neuropathy

The starting point for making a diagnosis are the feelings of the person affected: his descriptions of the symptoms can give the doctor important information as to whether the symptoms are most likely due to diabetic neuropathy or whether other causes are more obvious. Diabetes patients should visit their diabetologist or neurologist once a year to have the condition of their nerves checked, even without symptoms. The doctor will first perform a few simple function tests with which he will check the various sensory sensations (pain, touch, vibration and temperature) of the skin and the reflexes.This examination is usually started on the legs, as this is where diabetic neuropathy originates in most people. If the physical examination reveals the presence of diabetic neuropathy, further examinations can be carried out to confirm the suspicion and determine the extent of the damage. These include electromyography (EMG) and electroneurography (ENG) with measurement of nerve conduction velocity (NLG). If diabetic autonomic neuropathy is suspected, other examination methods are used: cardiac arrhythmias can be examined, for example, using a 24-hour ECG, while suspected circulatory instability using a so-called Schellong test (repeated blood pressure measurements before and after getting up quickly from a lying position) can be evaluated.

Determination of the nerve conduction velocity

The measurement of the nerve conduction velocity as part of an electroneurography (ENG) is probably the most common apparatus-based examination method for diagnosing and monitoring diabetic neuropathy. To do this, two electrodes are stuck to areas of the skin under which one and the same nerve runs. An electrical pulse is then emitted via one of the electrodes and the time elapsed until the signal arrives at the second electrode is then measured. The comparison with normal values ​​or with values ​​from previous examinations then provides information as to whether there is nerve damage or how the condition of the nerve has developed in comparison to the previous examination. The nerve conduction velocity can also be determined in the context of electromyography: For this purpose, the nerve to be examined is stimulated with an electrode and then the strength and time delay of the muscle response is measured using a muscle electrode.

What is the degree of disability for diabetic polyneuropathy?

The question of the degree of disability in diabetic polyneuropathy cannot be answered across the board. The classification depends on various factors, including above all the extent of the impairment caused by the polyneuropathy and the amount of therapy required for the underlying diabetes disease. In principle, it is irrelevant whether it is type 1 or type 2 diabetes, but type 1 is usually associated with greater effort because of the insulin injections that are absolutely necessary.

On the basis of these considerations, for example, a type 1 diabetic without serious other diseases and without consequential damage (such as a diabetic polyneuropathy) is currently classified at a degree of disability of 40. A degree of disability of at least 50 corresponds to a severe disability and, according to the Health Care Ordinance, requires more than three insulin injections per day, an independent adjustment of the insulin dose to the self-measured blood sugar level and serious changes in lifestyle. The little word "as well" is decisive here: Even if those affected argue that daily blood sugar measurements and insulin injections represent a significant break in lifestyle, these steps are considered by lawmakers to have been ticked off in the previous paragraph. Consequently, for a degree of disability of 50 additional incisions, such as polyneuropathy or diabetic foot syndrome, must exist.

Causes of Diabetic Neuropathy

As the name suggests, the cause of diabetic neuropathy is, by definition, diabetes. The nerve damage is based on a permanently increased blood sugar concentration, as can be the case with untreated or poorly treated diabetes mellitus. The damaging effect does not affect the sugar (Glucose) itself, but to one of its breakdown products, methylglyoxal. This is further broken down in the body by certain enzymes, which, however, are overwhelmed by permanently high blood sugar levels. In the long run, therefore, methylglyoxal accumulates, which disrupts the finely regulated ion transport processes in the nerve cells and thereby impairs their functionality. Research is currently being carried out into active ingredients that could lower methylglyoxal levels.