A Clinical Survey Of Chronic Neuropathic Pain

Objective: Neuropathic pain is chronic pain initiated by central or peripheral nerve lesions which can be caused by trauma, surgical procedures, nervous diseases or systemic disease attacked nervous system, chemical toxication, chemotherapy et al. The precise mechanism underlying neuropathic pain is unknown. The lack of information about the clinical characteristics of neuropathic pain is somehow affect its research direction and further prevention and treatment. This is extremely true in China because there is no data available about the overall picture of neuropathic pain. In this study, we have conducted a small scale clinical survey in four pain management centers in China in order to gain general clinical information and characteristics about neuropathic pain.Methods: A questionnaire was produced to investigate the multiple aspects about neuropathic pain which included general information, pain origins, the pain characters, the pain intensity, the therapy used and its efficacy. We have also asked in what degree that patients quality of life in influenced by the disease. This included work/homework capability, sleeping, emotion et al. Zung's self-rating depression scale was used to assess whether the patient is complicated with depression. The patient was interviewed according to the questionnaire by a trained interviewer after he or she had been diagnosed as neuropathic pain by two senior pain physicians. The duration of neuropathic pain is more than 1 month. Four pain management centers located in Sichuan, Jiangxi, Guangdong, and Shandong province joined the survey.Results: There were 143 patients with neuropathic pain participated this survey. We have found that the majority of patients were median and old people with 51.1 % of them were more than 60 yrs old. The duration of pain is from 1 month to 40 yrs. However, 78.6% is postherpetic neuralgia(PHN) patients whose durations were less than 3 months. There were sixteen types of neuropathic pain identified by this survey. Among them, the leading five types were PHN(32.2%), Trigeminal Neuralgia(25.9%), the Complex Regional Pain Syndrome(CRPS)(9.1%), spinal cord injured(7.0%), postsurgical neuralgia(6.3%). More than one descriptors are used by each patient to descript pain characters, the burning, itching, throbbing, wrapped, and expanding, were more common in secondary neuropathic pain, and the lightning and radiation in primary NP. 63.6% of CRPS type II patients had burning pain. The overall incidence of allodynia of all neuropathic pain patients was 26.8%, which was more common in phantom limb pain, CRPS, PHN. The overall incidence of hypesthesia of all patients was 23.2%. Average VAS of pain of all patients is 5.1 but the severity of phantom limb pain and central pain was over 6.0 which was severer than the other types of neuropathic pain. The quality of life including sleeping, emotion, work/homework capability, personal activity were affected by neuropathic pain. Among them, emotion was the one most affected. 94.4% patients had emotion change at different levels. Using Zung's self-rating depression scale , the incidence of depression condition of patients with neuropathic pain was 45.5%. However, only 7 of the patients in the total of 143 have accepted antidepressant treatment. In addition, patients with phantom limb pain and central pain were most likely to suffer from depression. 61.0% of the working professionals were forced to leave their jobs due to pain in our survey, and 36.9% of patients' families were experienced more economic burden because of the disease . The expectation for cure of pain was very high. Almost all patients hoped more than 80.0% pain relief. Many patients had received more than one therapy. These contained analgesics, herb medicine, physical therapy, acupuncture, and nerve blocks. Overall pain relief was 46.3% . Nerve blocks were the most effective treatment with 70.5% relief. The overall satisfaction for pain management was 45.1%.Conclusions: From this small scale survey, we have found that neuropathic pain tends to attack older people. PHN and Trigeminal Neuralgia are most common types of neuropathic pain. Pain characteristics vary according to its origins. Those findings may direct our future research towards how age may influence the development of neuropathic pain and the mechanisms underlying different origins of neuropathic pain. We have found neuropathic pain has affected patients' quality of life, emotion in particular. Many patients suffered from depression but very a few are treated by antidepressants. Patients have very high expectation for pain relief. These indicate that clinical care for neuropathic pain patients needs to be improved and some type of educational programs should be carried out to help patients adjust themselves to live with neuropathic pain. We have seen that the clinical picture of neuropathic pain in Chinese is different from those in western countries. Large scale national wide survey is necessary to gain profound knowledge about neuropathic pain in china which may be beneficial for China and the world.