Polyneuropathy: Symptoms, Treatment & Cure

Brief overview: Polyneuropathy

Definition: Polyneuropathy (PNP) is an umbrella term for various nerve diseases that are not caused by injury. Several (poly) nerves (neurons) of the peripheral nervous system are affected.

Symptoms: The symptoms of polyneuropathy are varied, depending on the nerves affected. Pain and discomfort are common.

Causes: Polyneuropathies are often the result of diabetes mellitus or alcohol abuse. Infections or other diseases can also trigger the nervous disease.

Course: The course of the disease can be very different, depending on the underlying cause and which nerves are affected.

Diagnose: Among other things, neurological examinations such as measuring nerve conduction velocity and checking reflexes and sensitivity.

Article content at a glance:

What is polyneuropathy?

Polyneuropathy damages or destroys the nerve fibers (axons) that connect the extremities or organs to the brain and spinal cord. This leads to a disturbance in the nervous transmission of stimuli. can

• sensory nerves that transmit nerve signals such as touch, heat, or pain

• or motor nerves, which are responsible for the voluntary execution of movements.

Polyneuropathy often starts in the feet because these nerves have to travel the longest distance to the spinal cord. However, the symptoms can also appear on the hands, arms and basically the entire body. Nerves of the autonomic nervous system, which controls the functioning of the internal organs, can also be affected.

Polyneuropathy: Various symptoms possible

In the case of polyneuropathy, the symptoms depend greatly on which nerves are affected. In most cases, the symptoms are equally pronounced on both sides of the body, but there are also asymmetric courses of the disease. Pain occurs in about half of the patients and can sometimes be very severe. Sometimes chronic pain syndrome occurs.

Sensory disturbances (sensory deficits) such as:

• Abnormal sensations such as numbness, tingling, “pins and needles” on the skin (paraesthesia)
• restlessness in the legs (restless legs syndrome), burning soles of the feet
• reduced sensitivity to heat and cold
• burning or stabbing pain, pain at rest, shooting pain attacks
• Unsteady gait and falls due to impaired positional sense

Movement disorders (motor failures):

If nerves of the autonomic nervous system are affected, disorders and failures of organs can also occur:

Treatment of polyneuropathy

The treatment options for polyneuropathy are based on two pillars: On the one hand, the cause of the nerve damage should be eliminated as quickly and effectively as possible. The success of the treatment and the recovery of those affected depend primarily on this. The second pillar is treating the symptoms with painkillers and maintaining or restoring muscle mobility with physiotherapy.

Depending on the cause of the polyneuropathy, different treatment methods and drugs are used:

• Antivirals for viral infections such as herpes zoster
• Antibiotics for bacterial pathogens such as Lyme disease
• Cortisone in autoimmune diseases and inflammatory causes

It is important to immediately avoid pollutants (noxae) that are possible triggers, for example in the professional environment, as well as absolute abstinence from alcohol in alcoholics.

Which painkillers help with nerve pain?

Long-lasting, chronic pain conditions are usually more difficult to treat than acute pain. To make matters worse, it often only becomes clear after two to four weeks whether a particular painkiller is working or not. Combinations of active ingredients are often more effective in polyneuropathies than individual drugs.

• Anticonvulsants: Anticonvulsants are most commonly used for pain therapy in polyneuropathies. Drugs such as gabapentin, pregabalin or carbamazepine are prescribed. However, they must not be taken in the case of certain diseases, for example hyperthyroidism (hyperthyroidism), glaucoma, prostate enlargement, psychoses, severe heart disease.

• Pain Relieving Patches: Patches with the active ingredients lidocaine or capsaicin are used for regionally limited neuropathic pain, such as after a herpes zoster infection.

• Classic painkillers: Ibuprofen, paracetamol or metamizol often have no effect on neuropathies. Therefore, opioids are often used for severe pain. However, they can cause side effects such as tiredness, dizziness or constipation and, in the long run, lead to habituation and psychological dependence.

• Antidepressants: Also show in pain treatment antidepressant success. They make the pain more bearable by weakening the transmission of stimuli.

• TENS (transcutaneous electrical nerve stimulation): In TENS, electrodes on the skin transmit electrical impulses to the peripheral nerves and thus stimulate the pain area. The effectiveness has not been backed up by studies, but pain relief can reportedly be achieved in around 60 percent of those affected.

Chronic pain conditions are a heavy burden for people with polyneuropathy, which can lead to depression and even suicide. Accompanying psychotherapy helps patients to learn how to actively deal with the pain.

Causes: diabetes, alcoholism, vitamin deficiency

Almost every third person with type 2 diabetes mellitus develops polyneuropathy. Diabetes is by far the most common cause. Persistently high blood sugar levels lead to circulatory disorders, the lipid metabolism is impaired and toxic proteins are formed, which damage the nerves and can lead to sensory disorders.

The second most common trigger for polyneuropathy is chronic alcohol abuse: one to two thirds of all alcoholics develop polyneuropathy over the years. Alcohol is a cytotoxin and mainly attacks the thin, peripheral nerve fibers. With consistent alcohol abstinence, the polyneuropathy can regress within a few months to years.

Table: Common causes of polyneuropathies

infectious diseases	Herpes zoster (shingles), borreliosis, syphilis (syphilis), HIV, mononucleosis, rubella, mumps, typhus, TBE
metabolic disorders	Diabetes mellitus, uremia (uraemia) due to kidney failure, wrong or unbalanced diet, nutrient absorption disorders such as celiac disease
circulatory disorders	Vascular and circulatory diseases such as peripheral arterial disease (PAVK), arteriosclerosis, inflammation of the blood vessels (vasculitis)
Poisons (toxic neuropathy)	Alcohol, environmental toxins (heavy metals, arsenic, lead, mercury, acrylamide), side effects of medication
Hormone	Overactive thyroid (hyperthyroidism), acromegaly, pregnancy
Gene mutations (hereditary neuropathy)	Amyloidosis, spinocerebellar ataxia (incoordination due to degeneration of the cerebellum)
Vitamin deficiency	Deficiency of B vitamins, especially B12 and B6, rarely overdose of vitamin B6
autoimmune diseases	Collagen diseases such as lupus erythematosus, rheumatoid arthritis
cancer	Tumors such as a plasmacytoma, lymphoma or myelosis

Diagnosis of polyneuropathy

The diagnosis begins with a detailed anamnesis interview with a description of the symptoms and known previous illnesses. During the physical examination, the doctor checks the sensitivity to touch of all skin areas using a cotton ball or brush and the reflexes with a reflex hammer. With a struck tuning fork, the vibration sensation and thus the depth sensitivity can be controlled.

Further diagnostic measures:

• Electromyography (EMG) provides information on whether nerve disorders or damage to the muscles are the cause of the symptoms.

• The nerve conduction velocity provides information about the stimulus transmission of nerves. In this way, the extent of nerve damage can be determined more precisely.

• An electrocardiogram (ECG) shows the extent to which the heart is affected by the polyneuropathy.

• If underlying diabetes mellitus is suspected, the long-term blood sugar value HbA1c can confirm the diagnosis.

• An infection can be detected by corresponding antibodies in the blood.

If no cause is found, a nerve biopsy can provide information about the trigger. A small sample of tissue is taken and examined under a microscope.

Life expectancy and course of polyneuropathies

Most polyneuropathies are chronic. The symptoms and signs develop slowly over weeks. The disease is often only diagnosed at an advanced stage – depending on the extent of the nerve damage, those affected are dependent on a walker or wheelchair in the final stages.

However, polyneuropathies can take a very different course, depending on the underlying cause:

• acute course: about four weeks (e.g. Guillain-Barré syndrome)

• subacute course: four to eight weeks (vasculitis)

• chronic course: eight weeks and longer (diabetic polyneuropathy)

• hochchronisch: lifelong (mainly hereditary neuropathies)

In most cases, the disease has no effect on life expectancy. Rather, pre-existing underlying diseases such as diabetes or alcoholism can influence them.

Is polyneuropathy curable?

The chances of recovery from polyneuropathy depend on whether the cause can be treated, how quickly the symptoms were recognized and whether irreversible nerve damage has already occurred.

After the onset of polyneuropathy initially causes only mild symptoms, the diagnosis is not always made in good time. If the underlying disease can be treated and the nerve damage has not progressed too far, the prognosis is good and the polyneuropathy can be completely cured. If the causative underlying disease cannot be eliminated, further nerve damage can usually be prevented or at least delayed with the right therapy.