井上 雅寛

An objective method to evaluate patient suitability for cognitive behavioral therapy (CBT) for chronic low back pain (LBP) is currently lacking. Inappropriate application can result in prolonged hospital visits and increased medical costs. Therefore, identifying an objective biomarker for evaluating suitability is crucial. This study focused on electroencephalogram (EEG) complexity as a potential biomarker for evaluating CBT suitability for chronic LBP, assessing its discriminative ability and identifying factors that impede treatment. Complexity was analyzed as multiscale fuzzy sample entropy (MFSE). Fifty patients with suspected psychosocial factors causing LBP along with 20 healthy volunteers were included. The analysis included 25 responders and 25 non-responders for CBT. MFSE showed significant effects of scale factor [F(19,171) = 14.82, p < 0.01, partial η2 = 0.622] and interaction between group and scale factor [F(38,171) = 7.34, p < 0.01, partial η2 = 0.620]. The low-frequency band MFSE score had an odds ratio of 10.768 (95% confidence interval: 8.263-10.044, p < 0.001). The low-frequency band showed a high discriminative ability (area under the curve: 0.825), with a cut-off value of 1.25. The low-frequency FMSE is a superior biomarker for predicting suitability for CBT. This method can quickly evaluate suitability, reducing the burden on medical professionals and patients, and lowering medical costs.

Background Symptoms of lumbar spinal stenosis (LSS) are associated with changes in blood flow to lower limbs. These changes in blood flow can be perceived as temperature variations, which can be visualized using thermography. We compared the relationship between the subjective symptoms of LSS and temperature variations before and after surgical intervention and investigated the associated patient factors. Methods Patients who underwent laminectomy for LSS were included. Plantar temperature was measured preoperatively and postoperatively using thermography. Subjective symptoms and patient backgrounds were assessed through interviews and medical records. Temperature differences were evaluated using the parameter ΔT, defined as the temperature of the limb with stronger symptoms minus the temperature of the limb with weaker symptoms. The analyses were performed based on these parameters. Results The symptoms improved following laminectomy, and ΔT showed a significant increase. Pain and ΔT were positively correlated preoperatively, whereas ΔT and numbness and neuropathic pain scores were negatively correlated postoperatively. Cauda equina symptoms were associated with a decrease in ΔT both preoperatively and postoperatively, whereas age and disease duration were associated with a postoperative decrease in ΔT. Conclusion The postoperative increase in ΔT, resulting from the alleviation of nerve compression, suggests a relationship between nerve dysfunction and decreased temperature. The preoperative correlation between pain and ΔT may be attributed to vasodilation mediated by calcitonin gene-related peptide. The postoperative correlation between ΔT and neurological symptoms may reflect an association between the extent of nerve damage and reduced blood flow. In particular, cauda equina symptoms may lead to decreased blood flow through dysfunction of the S region, causing a relatively sympathetic-dominant state due to impaired parasympathetic function. Our findings suggest the potential of using temperature measurements to visualize and objectively evaluate subjective symptoms.