This study examined the net changes in temperature at various regions of the lower extremities in an attempt to identify the regions demonstrating the most significant temperature changes following a lumbar sympathetic ganglion block (LSGB). Thermography was performed before and after the LSGB in 26 sympathetic nerve system disorder cases. The inspection points were the anterior and posterior surfaces of the thigh, the knee and leg, and the dorsal and plantar surfaces of the feet. The net increases in skin temperature following the LSGB (deltaT (net) ) at the plantar and dorsal surfaces of the feet, were 6.2 +/- 2.68 degrees C (mean +/- SD) and 3.9 +/- 1.89degrees C, respectively, which were higher than those observed in the other regions of the lower extremities (p < 0.05). The areas, in order of decreasing deltaT (net), are as follows: the plantar surface of the foot, the dorsal surface of the foot, the shin, the anterior surface of the knee, the calf, the posterior surface of the knee, the anterior surface of the thigh, and the posterior surface of the thigh. There was one case of orthostatic hypotension during the thermography procedure. In conclusion, thermographic imaging is a useful method for demonstrating the success of a LSGB in various diseases. An evaluation of the deltaT (net) on the plantar surface of the feet using thermographic imaging is the most effective, simple, and safe method for assessing a successful LSGB.
Adult ; Aged ; *Autonomic Nerve Block ; Back Pain/surgery ; Body Temperature ; Complex Regional Pain Syndromes/physiopathology ; Female ; *Ganglia, Sympathetic ; Human ; Hyperhidrosis/physiopathology ; Infrared Rays/*diagnostic use ; Leg/physiopathology ; Lumbosacral Region ; Male ; Middle Aged ; Syndrome ; *Thermography ; Treatment Failure

INTRODUCTIONComplex regional pain syndrome (CRPS) patients show impaired visuospatial perception in the dark, as compared to normal patients with acute nociceptive pain. The purpose of this study is 2-fold: (i) to ascertain whether this distorted visuospatial perception is related to the chronicity of pain, and (ii) to analyse visuospatial perception of CRPS in comparison with another neuropathic pain condition.

MATERIALS AND METHODSWe evaluated visual subjective body-midline (vSM) representation in 27 patients with post-herpetic neuralgia (PHN) and 22 with CRPS under light and dark conditions. A red laser dot was projected onto a screen and moved horizontally towards the sagittal plane of the objective body-midline (OM). Each participant was asked to direct the dot to a position where it crossed their vSM. The distance between the vSM and OM was analysed to determine how and in which direction the vSM deviated.

RESULTSUnder light condition, all vSM judgments approximately matched the OM. However, in the dark, CRPS patients, but not PHN patients, showed a shifted vSM towards the affected side.

CONCLUSIONWe demonstrated that chronic pain does not always impair visuospatial perception. The aetiology of PHN is limited to the peripheral nervous system, whereas the distorted visuospatial perception suggests a supraspinal aetiology of CRPS.

Adult ; Aged ; Complex Regional Pain Syndromes ; complications ; etiology ; Darkness ; Female ; Functional Laterality ; physiology ; Humans ; Male ; Middle Aged ; Neuralgia, Postherpetic ; complications ; Perceptual Disorders ; etiology ; physiopathology ; Peripheral Nervous System ; physiopathology ; Task Performance and Analysis