Importance of pain evaluation for more accurate diagnosis of painful diabetic polyneuropathy

Pain is a common problem in diabetic neuropathy, but relatively little has been published regarding the extent to which it needs to be addressed in clinical practice. Objective. To assess neuropathic pain profile and its association with quantitative sensory testing in painful diabetic polyneuropathy.
Material and methods. Altogether, 61 consecutive diabetic inpatients with symmetric neuropathic complaints were enrolled. Clinical neurological examination and quantitative sensory testing (QST) were performed. Patients were interviewed using the Neuropathic Pain Scale (NPS) and filled in the McGill Pain Questionnaire (MPQ).
Results. Of all patients, 49 (80.3%) had clinical diabetic polyneuropathy. Only 17 of these patients complained of lower extremity pain on an initial interview, while 27 marked it in the MPQ. The intensity of deep and superficial pain did not differ, but patients rated deep pain as more unpleasant than superficial (6.27±2.37 vs. 4.30±1.42 on the NPS, P=0.034). Superficial pain NPS items tended to correlate with QST results, while deep pain items did not. Only female gender (OR=7.87) and lower glycosylated hemoglobin level (OR=0.65) were predictive of pain in case of diabetic neuropathy.
Conclusions. Standard pain questionnaires were useful in identifying pain sufferers. At the same intensity, deep neuropathic pain was more unpleasant than superficial. Pain manifestation was associated with female gender and lower level of glycosylated hemoglobin.