Correlation of thermal deficit with clinical parameters and functional status in patients with unilateral lumbosacral radiculopathy.

Introduction: Lumbosacral radiculopathy is a pathological process that refers to the dysfunction of one or more spinal nerve roots in the lumbosacral region of the spine. Some studies have shown that infrared thermography can estimate the severity of the clinical manifestation of unilateral lumbosacral radiculopathy. This study aimed to examine the correlation of the regional thermal deficit of the affected lower extremity with pain intensity, mobility of the lumbar spine, and functional status in patients with unilateral lumbosacral radiculopathy.

Methods: This cross-sectional study was conducted at the Clinic for Physical Medicine and Rehabilitation of the Clinical Center Niš, Serbia. A total of 69 patients with unilateral lumbosacral radiculopathy of discogenic origin were recruited, with the following clinical parameters evaluated: (1) pain intensity by using a visual analogue scale, separately at rest and during active movement; (2) mobility of the lumbar spine by Schober test and the fingertip-to-floor test; and (3) functional status by the Oswestry Disability Index. Temperature differences between the symmetrical regions of the lower extremities were detected by infrared thermography. A quantitative analysis of thermograms determined the regions of interest with maximum thermal deficit. Correlation of maximum thermal deficit with each tested parameter was then determined.

Results: A significant and strong positive correlation was found between the regional thermal deficit and pain intensity at rest, as well as pain during active movements (rVAS - rest=0.887, rVAS - activity=0.890; P<0.001). The regional thermal deficit significantly and strongly correlated with the Oswestry Disability Index score and limited mobility of the lumbar spine (P<0.001).

Conclusions: In patients with unilateral lumbosacral radiculopathy, the values of regional thermal deficit of the affected lower extremity are correlated with pain intensity, mobility of the lumbar spine, and functional status of the patient.