The influence of sensory symptoms on overall simple pain ratings in neuropathic pain is not well understood. The goal of this study was to determine this relationship by using the Neuropathic Pain Questionnaire (NPQ) and Neuropathic Pain Scale (NPS) in patients who had neuropathic pain. Overall pain intensity ratings were assessed by means of Average and Worst Pain ratings from the Brief Pain Inventory. Ongoing average pain was rated as 5.7 and worst pain as 7.7 on 0 to 10 scale, and it was present in 96% of patients, whereas symptoms that are commonly studied in the laboratory, such as increased pain due to touch and due to heat, were much less frequent (64% and 38%, respectively). Worst pain was most highly correlated with shooting, stabbing, and distress symptom complex, which was in contrast to Average pain, which was most highly correlated with symptom complex consisting of a large number of items. Analysis of conceptually related thermal heat sensation types of pain, spontaneous "burning" pain and the evoked pain "increased due to heat," showed that spontaneous burning pain was reported at much higher frequency and intensity than the evoked increased pain due to heat. There was no statistically significant difference between descriptors from NPS and NPQ among subgroups of neuropathic pain, such as polyneuropathy, radiculopathy, or posttraumatic neuralgia, but this could be in part due to relatively small number of patients in these subgroups of neuropathic pain. Quantitative analysis, as performed in this study, is one of the steps in developing an approach for elucidating the relationship between neuropathic pain symptoms and underlying mechanisms.
Perspective: Assessment of neuropathic pain symptoms by means of specifically designed questionnaires provides significant insight into patients' pain experience, including pain overall, which is under many influences. Further research of this type can contribute to advances in mechanism-based diagnosis and treatment.