Use of sensory-sympathetic coupling indices for diagnosing sympathetically maintained pain with laser Doppler flowmetry

Abstract

For the first time the objective diagnosis of sympathetically maintained pain was created with laser Doppler flowmetry (LDF), directed specially to discovery of skin sensory-sympathetic coupling at 49 patients with posttraumatic complex regional pain syndrome. Sensory-sympathetic coupling was diagnosed as combination of sympathetic vasomotor activity with the existence of sensory peptidergic blood flow oscillations in frequency range of 0.047-0.069 Hz in LDF wavelet-spectrum. The results of LDF diagnosis were compared with clinical evaluation of sympathetically maintained pain carried out after desympathization surgery (thoracoscopic clipping above and below the Th3 ganglion of sympathetic chain at 33 patients and perivascular sympathectomy at the level of brachial artery and veins at 16 patients). Sensitivity of preoperative LDF-diagnosis was 90.2%, specificity--87.5%, positive predictive value--97.3%, negative predictive value--63.6%, diagnostic effectiveness--89.8%.