Short-Term Plastic Changes in Thalamic Functional Connectivity Following Balloon Compression for Trigeminal Neuralgia: A Longitudinal rs-fMRI Study

Objective This study aimed to investigate short-term plastic alterations in whole-brain functional connectivity (FC) of the thalamus in patients with trigeminal neuralgia (TN) after percutaneous balloon compression (PBC), and to provide longitudinal neuroimaging evidence for the reversibility of abnormal thalamic FC and remodeling patterns of thalamocortical networks following pain relief. Methods Thirty-two TN patients who achieved significant pain relief at 1-month follow-up after PBC and 32 age- and sex-matched healthy controls (HC) were recruited. Resting-state functional magnetic resonance imaging (rs-fMRI) and clinical pain scale assessments were performed for all participants. Seed-based FC analysis was conducted using the bilateral thalamus as regions of interest (ROIs). Intergroup cross-sectional comparisons and within-subject longitudinal comparisons were performed, followed by correlation analyses between FC metrics and clinical variables. Results Compared with HC, preoperative TN patients exhibited widespread thalamic FC abnormalities, including hyperconnectivity between the thalamus and somatomotor regions (right postcentral gyrus, left paracentral lobule), as well as hypoconnectivity between the right thalamus and bilateral fusiform gyrus and between the left thalamus and left fusiform gyrus. One month after surgery, these abnormal thalamo-somatomotor connections normalized to the levels observed in healthy controls. Nevertheless, decreased FC between the left thalamus and left fusiform gyrus, together with hyperconnectivity between the left thalamus and right superior frontal gyrus, persisted relative to HC. Longitudinal within-patient comparison revealed decreased FC between the thalamus and key default-mode network nodes, including the posterior cingulate cortex and angular gyrus. Additionally, increased FC was observed between the right thalamus and visual-related regions (calcarine gyrus, middle occipital gyrus), as well as the right superior temporal pole. No significant correlations between altered FC values and clinical variables survived false discovery rate correction. Conclusions Thalamocortical networks undergo heterogeneous remodeling within one month after effective PBC for TN. Aberrant functional connections within somatomotor pathways show reversible recovery, whereas pathways involved in cross-modal sensory integration and higher-order pain cognitive regulation demonstrate incomplete short-term repair. Moreover, adaptive functional reorganization takes place within the central nervous system after pain alleviation. These longitudinal findings indicate that the central response to pain relief constitutes a complex process encompassing reversible repair, residual pathological connectivity, and active adaptive network adjustment.