It is a simultaneous malfunction of many peripheral nerves. It is distinguished in acute (sudden onset) and chronic (progession over months or years). In addition, it may be hereditary. Depending on the cause, motor nerves, sensory nerves, cranial nerves or even a combination of the above may be impaired.
Causes of acute polyneuropathies:
- Bacterial inflammation.
- Use of some drugs (eg antibiotics, chemotherapeutics).
- Several types of cancers (eg multiple myeloma).
- Effect of toxic substances (eg thallium).
Causes of chronic polyneuropathies – are usually unknown, but may be due to:
- Eating defects.
- Lack of vitamin B12.
- Effect of toxic substances (eg lead).
- Hepatic insufficiency.
- Various types of cancers (eg lung).
- Vitamin B6 overdose.
Inherited polyneuropathies are caused by:
- Some types of Charcot-Marie-Tooth,
- Refsum disease,
- Fabry disease,
- Hereditary neuropathy with blood pressure problems.
Acute polyneuropathy (as in Guillain Barre Syndrome) suddenly starts from both feet and progresses rapidly to the hands. There is weakness and numbness or loss of feeling. Respiratory muscles may be affected leading to respiratory failure.
Chronic neuropathy affects only sensation. Usually legs are affected first, without excluding bruising, respectively. There is numbness, burning sensation, loss of sense of vibration or position, which leads to unsteady gait. Therefore, muscles are not used and weakness and obsolescence occur, thus they become rigid and present contractures.
People with hereditary polyneuropathies may experience scoliosis, hammering, have high arches in the legs. Usually, sensory abnormalities and weakness are mild, but there may not be a sense of pain perception, whenever injuries that cannot be perceived and be infected, leading to inflammation of bones and joints (neurogenic arthropathy).
Often, polyneuropathy affects nerves of the autonomic nervous system that controls the involuntary functions of the human body, such as blood pressure, heart rate, digestion, urination.
In addition, constipation, sexual dysfunction, orthostatic hypotension, pale and dry skin, and urinary and intestinal dysfunctions occur.
Management for each case depends on the cause.
- Clinical examination.
- Electromyography – Nerve conduction tests.
- Blood and urine tests.
- Muscle biopsy (rarely).
- Lumbar puncture.
- Spirometry (for respiratory function assessment).
- Pain management
- Physiotherapy – Occupational Therapy
- Depending on the cause:
- Diabetes management and control.
- Surgical removal of cancer.
- Treatment of multiple myeloma and hepatic insufficiency.
- Pharmaceutical treatment of hypothyroidism.
- Treatment of toxic side effects by administering immunoglobulins, corticosteroids, immunosuppressive drugs and blood plasma purification.
- Interruption of vitamin B6.
Information about clinical trials conducted globally: https://www.centerwatch.com/clinical-trials/listings/condition/288/chronic-inflammatory-demyelinating-polyneuropathy-cidp/ and
Polyneuropathy – Brain, Spinal Cord, and Nerve Disorders, Merck Manuals Consumer Version, http://www.merckmanuals.com/home/brain,-spinal-cord,-and-nerve-disorders/peripheral-nerve-disorders/polyneuropathy