An axon, which can be 1 foot (30.5 cm) long, is the part of a nerve cell that extends from the neuron to target cells. In axonal peripheral neuropathy, a person's axons may gradually die. The result is pain, inability to control muscles, and a lack of sensation. This condition has many causes, most commonly systemic disease such as diabetes or cancer. Other causes include alcoholism, vitamin deficiencies, adverse side effects from medication, and environmental toxins.
Axonal peripheral neuropathy is one of more than 100 types of peripheral neuropathy. Neuropathies are typically classified according to the problems they cause or what is at the root of the damage. Most peripheral neuropathies are distinguished by their cause — either the degeneration of the myelin sheath or the axon itself. Unlike demyelination neuropathies, in which the sheath of the nerve is damaged, the axons themselves die off in axonal peripheral neuropathy.
In the body, one set of nerves transmits information from the brain to the body, including the arms, feet, skin, and organs. Another set of nerves returns sensations, such as heat, cold, pressure, and pain, from those body parts to the brain. Peripheral neuropathy occurs when the information isn’t transmitted properly between the brain and other parts of the body.
When the axons die, less information is transmitted between the body and the brain. This means the body may lose its ability to control muscles or to direct organs, which can result in shaking, lack of coordination, or organ failure. Alternately, it may mean that information from nerves is not transmitted to the brain, which can result in an inability to feel a pin prick or pressure, or numbness from heat and cold. It also may lead to the brain's perception of imagined pain when no direct cause exists.
Axonal peripheral neuropathy can be caused by systemic disease, including diabetes and several cancers, such as breast cancer, lung cancer, lymphoma, and myeloma. It can also be caused by uremia, amyloidosis, porphyria, and cryoglobulinemia. In addition to systemic and chronic diseases, excessive alcohol consumption and inadequate vitamins can also produce this condition, as can drugs and environmental toxins.
The underlying cause of axonal peripheral neuropathy can frequently be treated. Treatments can be preventive or palliative. Fixing the cause of the problem, such as managing a diabetic's blood sugar more effectively, treating alcoholism, or discontinuing a drug with adverse side effects, also may result in a patient's improved condition.
Symptoms may be controlled and occupational therapy may help. Foot care, walking aids, and physical therapy may allow a patient to get around better. Disabled patients may need special utensils and home adaptations. Patients with neuropathic pain can get help from anti-convulsant drugs, tricyclic antidepressants, and opioid-like drugs.