Peripheral Neuropathy describes a damage of peripheral nerves, showing different symptoms depending on the affected region. “Peripheral” nerves are those nerves that lie outside the brain and spinal marrow. These nerves fulfill important tasks with regard to the control of the body. If sensitive nerves are affected, tingling sensations of the skin can occur. The damage of motor nerves leads right up to muscular atrophy. In case sensory nerves are affected the patient can lose sensual impressions.
Primary neuropathies originate from the nerve itself and are commonly genetically predisposed. Secondary neuropathies have different underlying causes, including inflammation, autoimmune or metabolic diseases, as well as substances that are toxic to the nerves.
If a single nerve is affected, the disease is called mononeuropathy. In contrast, polyneuropathy describes the case of multiple affected nerves. Mononeuropathy can occur due to an injury. The local damage of a nerve segment leads to symptoms that are restricted to a certain body area. The carpal tunnel syndrome is one example for this. The most commonly appearing polyneuropathy, which causes health problems throughout the body, is the diabetic polyneuropathy. In diabetic polyneuropathy certain metabolic products that cannot be degraded by the body accumulate inside the nerve tissue. As a consequence, the function of the affected nerves gets lost. Demyelinations, which mean that the protecting nerve sheaths are harmed, are reversible under certain circumstances.
Therapy of Peripheral Neuropathy
For the therapy of peripheral neuropathy the cause of the disease has to be treated. In case of alcohol or drug abuse it is usually possible to achieve improvements already by stopping the intake of these substances. If there is a lack of B vitamins, folic acids, or vitamin E it is useful to supply the body with these substances.
If the cause originates from pathogens of Lyme borreliosis, antibiotic or virostatic therapy is typically necessary. If the neuropathy is primarily caused by an autoimmune disease, immunosuppressants, immunoglobulins, or corticosteroids might be given. Stem cell therapy gives hope that the intake of those drugs, which have many side effects, can be avoided. Furthermore, a frequent exchange of blood plasma (plasmapheresis) can be done.
In diabetic polyneuropathy the correct blood sugar adjustment is essential. Harmful glucose deposits inside the tissue (glycosylation) can be removed by infusion therapy with alpha lipoic acid.
In addition, the symptoms of peripheral neuropathy have to be treated. Chronic pain can be relieved with analgesics, antidepressants, or by inhibiting the nerve excitability. Muscle cramps can be treated by taking in magnesium. In restless legs syndrome the administration of dopamine can help. Pressure marks on numb arms and legs can be avoided by using adequate padding. In case of paralysis physical therapy can be performed.
Stem Cell Therapy in Peripheral Neuropathy
Mesenchymal Stem Cells (MSC) or Stromal Vascular Fraction (SVF) isolated from the patient’s fat tissue can be used therapeutically in peripheral neuropathy. Stem cells are said to be precursor cells of all completed body cells. In the meanwhile we know that mesenchymal stem cells primarily act via modulating the immune system and stimulating regeneration of tissue and blood vessels by cytokines. Peripheral neuropathy has a degenerative component and commonly faulty reactions of the immune system are present. Thus the application of mesenchymal stem cells proposes itself.
Stem cells from fat tissue have already shown promising results in the treatment of a number of autoimmune diseases. That’s why they may also pose a treatment option in peripheral neuropathy that is normally not causally treatable. There is a reasonable cause for hope that the injection of mesenchymal stem cells extracted from a small portion of the patient’s body fat can help to alleviate the course of disease.
Basically, it is possible to cultivate nerve cells from stem cells “artificially” in the lab and to implant these new nerve cells afterwards. Such therapies are currently researched in studies. Apart from the clinical practicability in all patients the reason for the neuropathy (e.g., an autoimmune disease) has to be remedied, otherwise the new nerve cells would be attacked by the body as well.
With the aid of mesenchymal stem cells and SVF it might be possible to modulate the immune system and thereby to decelerate the advancement of the autoimmune disease peripheral neuropathy. Moreover, mesenchymal stem cells and SVF are capable of stimulating the stationary stem cells of nerve cells to regenerate and can thus possibly counteract the destruction of further neurons. In future, the application of cultivated nerve cells would possibly come into consideration only as a second step.