Study of verbal description in neuropathic pain.

The aim of this paper is to study the quality of verbal description and its diagnostic value in neuropathic pain. The verbal description of pain as assessed by a French adjective list questionnaire (QDSA) is compared between a group of 100 patients with neuropathic pain and a mixed group of 97 chronic benign and cancer non-neuropathic pain patients. Seventeen descriptors of the 61 QDSA descriptors have a significant intergroup frequency difference. By principal component analysis and Varimax rotation of the intercorrelation matrix of descriptors in the neuropathic group. 7 factors accounting for 66.0% of the total variance are derived. Six factors reflect purely sensory or affective aspects of the pain experience. Seven descriptors from the discriminant analysis function correctly assign 77% of neuropathic pain patients and 81% of the non-neuropathic pain patients. In a second neuropathic pain group of 32 patients, the discriminant function coefficient permits correct diagnostic categorization in 66% of the cases. Implications for clinical practice and trials are discussed.