Neuropathic pain is caused by damage or disease in the nervous system. It's estimated that more than 5% of the global population is affected, often severely.
Central neuropathic pain is found in spinal cord injury, multiple sclerosis, and some strokes. Peripheral neuropathies are commonly caused by diabetes, metabolic disorders, herpes zoster infection, HIV-related neuropathies, nutritional deficiencies, toxins, remote manifestations of malignancies, immune mediated disorders and physical trauma to a nerve trunk. Neuropathic pain is common in cancer as a direct result of cancer on peripheral nerves (e.g., compression by a tumor), or as a side effect of chemotherapy (chemotherapy-induced peripheral neuropathy), radiation injury or surgery."
Source Wikipedia
Although it's known that the pain results from nerve damage - either central or peripheral - the precise mechanisms which lead to the sensation of pain are unclear. One dominant hypothesis is that 'pain inhibitory neurons' - which are thought to moderate pain sensations - are themselves damaged. To date, no experiment has been able to confirm this.
Other theories, also experimentally unconfirmed, suggest involvement of Glia cells - non-firing neural cells which provide support and protection to firing neurons.
The subject is the focus of intense research in order to find safe, benign ways to control pain - especially in cancer patients.
Importance Rating