Compressing the lumbar nerve root changes the frequency-associated cerebral amplitude of fluctuations in patients with low back/leg pain

Understanding the central mechanisms responsible for lumbar nerve root compression may facilitate the development of new therapeutic strategies. In this study, our aim was to investigate the amplitude of fluctuations (AF) in five specific frequency bands and the full-frequency band realm to provide novel insight into the rhythm of the neuronal activity of low back/leg pain (LBLP) patients (n = 25). Compared with healthy controls, LBLP patients exhibited a significantly altered AF in multiple brain regions, including the right or left middle and inferior temporal gyri, bilateral precuneus, right anterior insula/frontal operculum, right or left inferior parietal lobule/postcentral gyrus, and other locations at five specific frequencies (P < 0.01, with Gaussian random field theory correction). Trends of an increase and a decrease in the AF in pain-and sensory-related regions, respectively, were also observed from low to high frequencies (Bonferroni-corrected a level of P < 0.05/84). In addition, in the bilateral rectal gyrus, a significant association was identified between the AF in the five specific frequency bands and disease status (P < 0.05). These findings suggest that in LBLP patients, intrinsic functional plasticity related to low back pain, leg pain and numbness affects the AF of the pain matrix and sensory-processing regions in both low-and high-frequency bands.