lillysgrandma's Cancer Blog

February 10, 2007

In keeping with my attempt to educate cancer patients of the side effects associated with cancer drugs, here is my latest discovery:

Neuropathy, strictly speaking, is any disease that affects the nervous system. In common usage, however, neuropathy is short for peripheral neuropathy, meaning a disease of the peripheral nervous system.

The four major forms of nerve damage are polyneuropathy, autonomic neuropathy, mononeuropathy, and mononeuritis multiplex. The most common form is peripheral polyneuropathy, which mainly affects the feet and legs.
Neuropathic pain is common in cancer as a direct result of the cancer on peripheral nerves (e.g., compression by a tumor), as a side effect of many chemotherapy drugs, and as a result of electrical injury.
Neuropathy often results in numbness, abnormal sensations called dysesthesias and allodynias that occur either spontaneously or in reaction to external stimuli, and a characteristic form of pain, called neuropathic pain or neuralgia, that is qualitatively different from the ordinary nociceptive pain one might experience from stubbing a toe or hitting a finger with a hammer.

Neuropathic pain is usually perceived as a steady burning and/or “pins and needles” and/or “electric shock” sensations. The difference is due to the fact that “ordinary” pain stimulates only pain nerves, while a neuropathy often results in the firing of both pain and non-pain (touch, warm, cool) sensory nerves in the same area, producing signals that the spinal cord and brain do not normally expect to receive.

Neuropathic pain can be very difficult to treat. Sometimes strong opioid analgesics may provide only partial relief. Opioid analgesics are to be considered only as a tertiary treatment. Several classes of medications not normally thought of as analgesics are often effective, alone or in combination with opioids and other treatments. These include tricyclic antidepressants such as amitriptyline (Elavil®), anticonvulsants such as gabapentin (Neurontin®) and pregabalin (Lyrica®).