Neuropathic pain is a complex, chronic pain state that is generally accompanied by tissue injury. With neuropathic pain, the nerve fibers themselves might be damaged, dysfunctional, or injured. These damaged nerve fibers send incorrect signals to other pain centers. The clinical causes of neuropathic pain are widespread and include both trauma and disease. For example, traumatic nerve compression or crush and traumatic injury to the brain or spinal cord are common causes of neuropathic pain. Furthermore, most traumatic nerve injuries also cause the formation of neuromas, in which pain occurs as a result of aberrant nerve regeneration. In addition, cancer-related neuropathic pain is caused when tumor growth painfully compresses adjacent nerves, brain or spinal cord. Neuropathic pain is associated with diseases such as diabetes or alcoholism.
Unfortunately, the available drug therapies for neuropathic pain often do not provide the patients in need of such treatment the adequate pain relief. In addition, current therapies have serious side-effects including, for example, cognitive changes, sedation, nausea and, in the case of narcotic drugs, addiction. Many patients suffering from neuropathic pain are elderly or have other medical conditions that particularly limit their tolerance of the side-effects associated with available drug therapy. A number of anti-inflammatory, anxiolytic, narcotic and even anti-convulsants are currently used by the practitioners to treat neuropathic pain, but with limited success.
The inadequacy of current therapy in relieving neuropathic pain calls for new compositions and methodologies of addressing the physical and social needs of the patient suffering from such condition. Methods of alleviating neuropathic pain would improve the quality of life for many people suffering from pain due to trauma or disease.