Hyperthermia associated with spinal radiculopathy as determined by digital infrared thermographic imaging

Abstract

In general, in digital infrared thermographic imaging (DITI) of patients with unilateral spinal radicular pain, the thermal pattern of the extremities of the side of lesion shows hypothermia compared to the opposite, intact side. However, sometimes, DITI shows hyperthermia on the side of the lesion, and this variation can cause confusion. We compared the data of both hypothermia and hyperthermia patients to clarify the factors determining different thermal characteristics in spinal radiculopathy. We retrospectively collected data from patients who underwent DITI at a single center. The final cohort (n = 224) was allocated into 2 groups, a hypothermia group (n = 180) or a hyperthermia group (n = 44). We compared the various factors, including demographic factors and symptom-related factors, that might affect the results of DITI. Except the presence of trauma history (13.9% vs 31.8%, odds ratio 2.893, P = .008), no significant intergroup difference was found in baseline demographic factors, including age, gender, diabetes mellitus, spinal level of pathology, and intervention history. Among symptom-related factors, in the hyperthermia group, the symptom duration was shorter (10.64 weeks [95% confidence interval (CI) 8.36–13.04] vs 2.10 weeks [95% CI 1.05-3.53], P < .001) and Visual Analogue Scale (VAS) of radicular pain was higher (4.23 ± 1.29 vs 5.18 ± 1.40, P < .001) than in the hypothermia group. Also, in the regression analysis, significant factors for hyperthermia include the presence of trauma history, shorter symptom duration (cut-off value 2.50 weeks or less) and higher VAS of radicular pain (cut-off value 4.50 or more). In patients with trauma history, acute phase, and severe radicular pain, hyperthermia in DITI is not unusual and careful interpretation of the DITI results is necessary for proper diagnosis and treatment decisions in spinal radiculopathy.

Reference Standard for Digital Infrared Thermography of the Surface Temperature of the Lower Limbs

“…In previous clinical studies, the normal range of |ΔT| was limited to 0.2 °C, although it varied depending on the region [ 10 , 15 , 17 ]. According to the present study, |ΔT| was within 0.2 °C, as suggested previously in almost all ROIs except in the lateral-side area.…”

“…Furthermore, |ΔT| was within 0.2 °C in the sole area and it was measured as higher than 0.2 in the lateral-side area. In contrast, some authors have suggested that |ΔT| increases toward the distal part of the body and that the normal range of |ΔT| can be larger than 0.2 °C in the periphery [ 10 , 17 ]. As a result, previous findings are controversial, and it is necessary to be careful about the interpretation of the significance of |ΔT| depending on the area.…”

“…DITI has been used as a complementary diagnostic tool in various clinical fields [ 3 , 4 , 5 , 6 , 7 , 8 , 9 ]. In several disorders involving the lower limbs, such as lumbar radicular pain, chronic regional pain syndrome, vascular disease, and peripheral nerve entrapment, DITI allows visualization of the affected area as hypo-radiant (hypothermia) or hyper-radiant (hyperthermia) compared to the unaffected area [ 10 , 11 , 12 , 13 , 14 , 15 ].…”

Differential Screening of Herniated Lumbar Discs Based on Bag of Visual Words Image Classification Using Digital Infrared Thermographic Images

“…Perhaps this is because the left and right sides are not added as labels. Park et al, reported that the other confusing factors are that DITI shows hyperthermia sometimes on the side of the lesion rather than the thermal pattern of the extremities on the side of the lesion shows hypothermia compared with the opposite, usually when in the acute phase, trauma, and severe pain [ 32 ]. Considering those points, if it is applied to the feet of HLD L4/5 and L5/S1 patients, the patient’s history, such as symptom duration, and pain scale, the accuracy will be better.…”

Reference Standards for Digital Infrared Thermography Measuring Surface Temperature of the Upper Limbs

“…Digital infrared thermographic imaging (DITI) has been utilized as an ancillary diagnostic method for various medical conditions related to the upper extremities. For instance, cervical radiculopathy; peripheral nerve entrapment syndrome (e.g., carpal tunnel syndrome); rheumatic disease (e.g., Raynaud’s disease); complex regional pain syndrome; tendinopathy; hand arthritis (e.g., psoriatic arthritis); and skin cancer can be confirmed by DITI [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 ]. The hypo-radiant (hypothermia) or hyper-radiant (hyperthermia) regions can be identified by comparing the temperature between the right and left arms or with empirical normal ranges.…”