Use of Sensory—Sympathetic Coupling Indices for Diagnosing Sympathetically Maintained Pain with Laser Doppler Flowmetry

摘要

The first objective diagnosis of sympathetically maintained forms of pain employing laser Doppler flowmetry (LDF) and specifically targeted at detecting sensory-sympathetic coupling in the skin has been developed and tested in 49 patients with the posttraumatic complex regional pain syndrome. Sensory-sympathetic coupling was diagnosed as a combination of sympathetic vasomotor activity and the presence of sensory peptidergic blood flow oscillations in a frequency band of 0.047-0.069 Hz in the LDF wavelet spectrum. The results of the LDF diagnosis were compared with the clinical evaluation of sympathetically maintained pain carried out after desympathization surgery (thoracoscopic clipping above and below the Th3 ganglion of the sympathetic chain in 33 patients and perivascular sympathectomy at the level of the brachial vascular bundle in 16 patients). The sensitivity of preoperative LDF diagnosis was 90.2%; the specificity was 87.5%; the positive predictive value was 97.3%; the negative predictive value was 63.6%; and the diagnostic efficiency was 89.8%.