Nociceptive and neuropathic pain in patients with lung cancer: A comparison of pain quality descriptors

Predictive validity of each word from the McGill Pain Questionnaire (MPQ) h as not been investigated in relation to pain etiology. The purpose of this study was to explore differences in the words used to describe nociceptive and neuropathic pain. Patients with lung cancer (N = 123) selected words fr om the 78 MPQ pain quality descriptors and indicated the corresponding pain site for each word. Using only the MPQ pain location, and the cancer and t reatment data abstracted from medical records, each pain site was classifie d as nociceptive or neuropathic (etiology). Pain etiology and quality descr iptors were tested for proportional differences with sensitivity, specifici ty, and predictive value calculated for statistically significant descripto rs. Of the 457 pain sites, 343 were classified as nociceptive (75%), 114 as neuropathic (25%). Lacerating, stinging, heavy, and suffocating were selec ted for a significantly larger proportion of nociceptive sites whereas thro bbing, aching, numb, tender, punishing, pulling, tugging, pricking, penetra ting, punishing, miserable, and nagging were selected for a larger proporti on of neuropathic sites. Ten words correctly predicted 78% of the sites wit h 81% sensitivity to nociceptive pain and 59% sensitivity to neuropathic pa in. Interestingly, several pain quality descriptors (burning, shooting, fla shing, tingling, itching, and cold) previously associated with neuropathic pain, did not distinguish between neuropathic and nociceptive pain. Infrequ ent selection of many MPQ words and lack of neurological exam data in the m edical records are possible explanations for inconsistency with previous li terature. Prospective studies are needed to validate pain quality descripto rs for nociceptive and neuropathic types of lung cancer pain. J Pain Sympto m Manage 2001: 22:899-910. (C) U.S. Cancer Pain Relief Committee, 2001.