Sympathetic pathology evidenced by hand thermal anomalies in carpal tunnel syndrome

Infrared thermographic changes after decompression surgery in patients with carpal tunnel syndrome

BACKGROUND

Digital infrared thermal imaging (DITI), which detects infrared rays emitted from body surface to create a body heat map, has been utilized at various musculocutaneous conditions. Notably, DITI can demonstrate autonomic vasomotor activity in the nerve-innervated area, and thus may be of use in carpal tunnel syndrome (CTS). In this study, we compared DITI findings before and after carpal tunnel release (CTR) surgery in patients with unilateral CTS to investigate the corresponding neurophysiological changes.

METHODS

In this retrospective cohort study, DITI parameters such as the temperature differences between the median and ulnar nerve territories and median nerve-innervated digital anisometry were measured. Subjective symptom duration, pain scale, and ultrasonographic findings were also compared before and after CTR. Patients were evaluated before and 6 weeks after CTR, respectively.

RESULTS

A total of 27 patients aged 59.0 ± 11.2 years were finally included. After CTR, median nerve-innervated thermal anisometry was improved (2.55 ± 0.96 °C to 1.64 ± 1.34 °C; p = 0.003). The temperature differences between the median and ulnar nerve territories were not significantly changed. Subjective pain, the Simovic Weinberg Clinical Scale, and palmar bowing of the flexor retinaculum were also significantly improved (p <  0.001 for all comparisons).

CONCLUSIONS

Our results demonstrated that DITI findings could reflect an improvement in autonomic function after CTR. Therefore, DITI can be an objective method to assess pre- and post-operative neurophysiologic changes in CTS.

Temperature Asymmetry Analysis between Left and Right Wrist with Sensory and Infrared Thermography

This article reports a thermal analysis of the wrists to analyze the behavior and recovery of skin temperature after 20 min when performing a highly repetitive movement, and two thermography methods (sensory and infrared) and research groups were compared. The tests were carried out with 44 participants who performed a repetitive task for 10 min and integrated into two groups, of which 22 were trained workers from a maquiladora company and were analyzed with sensory thermography, and the other 22 were in the laboratory with infrared thermography with undergraduate students. The study area is the left and right hand, specifically the wrists. The proposed hypothesis is that people with some musculoskeletal problems have a decrease in temperature when starting repetitive tasks and thermal asymmetries, which measurements were recorded at 0, 10, 15, and 20 min after the task was finished. Findings indicate that the temperatures in both wrists behave similarly. The workers reached higher temperatures, and the centigrade degrees of asymmetry difference were also higher. The variable with influence on the temperature was fractured in the arm. After thermally analyzing the temperature behavior between the wrists of both hands, it is concluded that there is an increase in temperature after finishing a repetitive task, and it does not stabilize after 20 min. Both thermography methods observed that the asymmetries are greater than 0.5 °C, detecting the possible pathology of carpal tunnel syndrome.

Application of digital infrared thermography for carpal tunnel syndrome evaluation

We investigated the thermographic findings of carpal tunnel syndrome (CTS). We enrolled 304 hands with electrodiagnostically identified CTS and 88 control hands. CTS hands were assigned to duration groups (D1, < 3 months; D2, 3‒6 months; D3, 6‒12 months; D4, ≥ 12 months) and severity groups (S1, very mild; S2, mild; S3, moderate; S4, severe). The temperature difference between the median and ulnar nerve territories (ΔM-U territories) decreased as CTS duration and severity increased. Significant differences in ΔM-U territories between the D1 and D3, D1 and D4, D2 and D4, and S1 and S4 groups (P = 0.003, 0.001, 0.001, and < 0.001, respectively) were observed. Thermal anisometry increased as CTS duration and severity increased. Significant differences in thermal anisometry between the D1 and D4 as well as the D2 and D4 groups (P = 0.005 and 0.04, respectively) were noted. Thermal anisometry was higher in the S4 group than in the S1, S2, and S3 groups (P = 0.009, < 0.001, and 0.003, respectively). As CTS progresses, skin temperature tends to decrease and thermal variation tends to increase in the median nerve-innervated area. Thermographic findings reflect the physiological changes of the entrapped median nerve.

Thermography in the diagnosis of carpal tunnel syndrome

INTRODUCTION

Carpal tunnel syndrome (CTS) is a condition caused by chronic compression of the median nerve. The diagnosis is made mainly on the basis of clinical image and confirmed with electrodiagnostic testing (electromyography and nerve conduction study); however, these methods do not always aid in reaching the diagnosis of CTS. Moreover, they are invasive examinations, unpleasant for the patient and have to be performed by a qualified physician.

AIM

An evaluation of the usefulness of dynamic thermography in the diagnosis of CTS.

MATERIAL AND METHODS

Forty patients were included in the study group. CTS was diagnosed based on clinical examination and electromyography. Forty healthy volunteers were included in the control group. Each of the participants was examined thrice with dynamic thermography. The patient's hands were first cooled down and then a thermal camera measured their return to normal temperature. The measurement was repeated on the dorsal and volar aspects of each hand.

RESULTS

The results obtained in the study show that a relief of symptoms after carpal tunnel release does not correlate with thermal image. Moreover, the return to normal hand temperature was faster in the control group. In patients with unilateral CTS, no difference was observed in thermographic images of the affected and healthy hands.

CONCLUSIONS

Dynamic thermography can be useful in confirming CTS diagnosis.Dynamic thermography does not allow for objective assessment of patient's complaints in the postoperative period.This method has currently limited clinical application. Due to complexity, it presently serves mainly scientific purposes.

Can we use thermal imaging to evaluate the effects of carpal tunnel syndrome surgical decompression?

Research is intended to verify if thermal imaging can be used in diagnosing and monitoring the carpal tunnel syndrome (CTS).This disease is not easy to diagnose using traditional methods. Also, the difficulties in monitoring carpal tunnel surgery effects necessitate new, noninvasive method, which gives more information.The research group consists of 15 patients with CTS and control group of healthy people. All patients who were examined before surgery were also tested 4 weeks after surgery, to check the effects of treatment. In addition a lot of our patients had or will have open carpel tunnel release surgery. Diagnosis of CTS was performed by thermal imaging in both hands from phalanges to the area of the wrist on the external and palmar side of the palm.Using infrared (IR) camera one can observe high temperature gradient on hand-tested areas and these differences prove the diagnosis. Moreover patients after surgery have better temperature distribution and it was closer to control group. Results prove that surgery is the best, and currently, the only method to treat CTS.Thermal imaging may be helpful in diagnosing CTS.

Accuracy of infrared thermography of the masticatory muscles for the diagnosis of myogenous temporomandibular disorder

OBJECTIVE

The purpose of this study was to evaluate the accuracy of infrared thermography of the central point of the masseter and anterior temporalis muscles for the diagnosis of myogenous temporomandibular disorder (TMD).

METHODS

This is an observational study of university women with and without TMD. Through the use of the Research Diagnostic Criteria for Temporomandibular Disorders, 104 women were divided into a TMD group (n = 52) and control group (n = 52). All volunteers had their masseter and anterior temporalis muscles evaluated by infrared thermography. The receiver operating characteristic (ROC) curve was used to determine the accuracy of diagnosis (area under the ROC curve), the best cut-off point, sensitivity, and specificity.

RESULTS

No significant differences were observed (P > .05) in the skin surface temperature of the masticatory muscles, when the groups were compared. With regard to the ROC curve, the area under the curve was lower than the recommended for all the muscles tested, ranging from 0.433 to 0.502.

CONCLUSION

The findings of this study suggest that infrared thermography of the masticatory muscles is not an accurate instrument for the myogenous TMD diagnosis.

Dynamic Doppler evaluation of the radial and ulnar arteries in patients with carpal tunnel syndrome

OBJECTIVE

The objective of our study was to evaluate the blood flow characteristics of the radial and ulnar arteries of the hands of patients with carpal tunnel syndrome (CTS) either in the neutral position or in provocative positions using color Doppler imaging.

SUBJECTS AND METHODS

Subjects with relevant complaints of CTS and positive Tinel sign and/or Phalen maneuver were recruited. Nerve conduction studies were performed to confirm the diagnosis of CTS. Forty-four hands of 22 patients with CTS (bilateral involvement) and 24 hands of 12 healthy volunteers were included in the study. Pulsed and color Doppler evaluations with the hands in the neutral, Phalen, and reverse Phalen positions were performed of the radial and ulnar arteries using a 5-13-MHZ linear-array transducer (Logiq 9).

RESULTS

All of the CTS patients and control subjects were women; their mean ages were 50.77 ± 7.69 (SD) and 46.42 ± 4.32 years, respectively. When hands were evaluated in the neutral position, the flow volume, peak systolic velocity, end-diastolic velocity, and diameter values of both the radial and ulnar arteries were significantly greater in patients with CTS than in control subjects (all p < 0.05). When compared with the measurements obtained with hands at the neutral position, the decreases in the amount of blood flow during the Phalen and reverse Phalen maneuvers were significantly greater in the CTS group than the control group. The amount of blood flow decrease was not correlated with the disease duration.

CONCLUSION

Blood flow in the hands of CTS patients differs from that of healthy individuals both at rest and during certain hand movements. Future studies, also with simultaneous monitoring of sympathetic innervation, could be beneficial to confirm the association between blood flow and the sympathetic nerves of the hand.

Postoperative relieve of abnormal vasoregulation in carpal tunnel syndrome

OBJECTIVE

To study the skin temperature changes as a sign of altered blood flow regulation due to abnormal sympathetic nerve function in carpal tunnel syndrome (CTS) and the efficacy of carpal tunnel release (CTR) operation in the alleviation of those signs and other symptoms of CTS.

SUBJECTS AND METHODS

Forty-one healthy hands (n=41) of 22 volunteers and 22 hands (n=22) with clinically diagnosed carpal tunnel syndrome of 16 patients were examined. A series of infrared photos of the hands of each subject were taken and stored by using digital infrared thermography (DIRT) before and 6 months after the CTR. The temperatures of the finger tips from digit 1 (D1) to digit 5 (D5), the center point of thenar (Th) and hypothenar (Ht) eminences were measured, the median nerve index (MI=(D1-D2)+(D1-D3)+(D2-D3)) and the temperature differences between the median and the ulnar nerve distribution area (MED.ULN=(D1-D5)+(D2-D5)+(D3-D5)+(Th-Ht)) were calculated. Absolute values were used when calculating the temperature differences between different points.

RESULTS

All the CTS patients were released from the CTS symptoms, i.e. numbness and pain after the operation, and the results of nerve conduction studies (NCS) were all back to normal. The MI and MED.ULN in CTS hands were significantly smaller before CTR compared to those of healthy control subjects (MI: p<0.001, MED.ULN: p<0.005), and those after CTR (p<0.005 for both parameters). The results also showed that all finger tips of the affected hand including those innervated by the ulnar nerve were cooler before but warmer after the operation. Before the operation, the non-CTS hands of the CTS patients, were also colder (although the difference was not significant) than the healthy control subjects but approached the same level after the CTR operation of the CTS hands.

CONCLUSION

The results of DIRT measurements suggest that the blood flow regulation in CTS is abnormal possibly because of disturbed sympathetic vasomotor regulation and that the circulation gets normal together with the alleviation of the other symptoms of CTS as recorded 6 months after CTR operation.

Hypothalamus and amygdala response to acupuncture stimuli in Carpal Tunnel Syndrome

Brain processing of acupuncture stimuli in chronic neuropathic pain patients may underlie its beneficial effects. We used fMRI to evaluate verum and sham acupuncture stimulation at acupoint LI-4 in Carpal Tunnel Syndrome (CTS) patients and healthy controls (HC). CTS patients were retested after 5 weeks of acupuncture therapy. Thus, we investigated both the short-term brain response to acupuncture stimulation, as well as the influence of longer-term acupuncture therapy effects on this short-term response. CTS patients responded to verum acupuncture with greater activation in the hypothalamus and deactivation in the amygdala as compared to HC, controlling for the non-specific effects of sham acupuncture. A similar difference was found between CTS patients at baseline and after acupuncture therapy. For baseline CTS patients responding to verum acupuncture, functional connectivity was found between the hypothalamus and amygdala--the less deactivation in the amygdala, the greater the activation in the hypothalamus, and vice versa. Furthermore, hypothalamic response correlated positively with the degree of maladaptive cortical plasticity in CTS patients (inter-digit separation distance). This is the first evidence suggesting that chronic pain patients respond to acupuncture differently than HC, through a coordinated limbic network including the hypothalamus and amygdala.