348 Comparison of Brain Functional Imaging of Pain States Using Resting-State fMRI and Multi-Delay pCASL to Clinical Scores of Pain in Chronic Low Back Pain Patients Implanted With Thoracic Spinal Cord Stimulation

Abstract

INTRODUCTION: Thoracic spinal cord stimulation (tSCS) is an interventional option for patients with refractory chronic low back pain (cLBP). The use of functional imaging of brain regions involved in pain as a quantitative method to evaluate treatment effectiveness has not yet been studied. METHODS: pCASL data using 5 post-label delays (0.5-2.5s) alongside rs-fMRI data was gathered from five patients (4 M, 1F) post-tSCS with cLBP post-implantation with the SCS device turned off at a 3.0T scanner. Arterial transit time (ATT), cerebral blood flow (CBF), and cerebral blood volume (CBV) were derived from pCASL data. Amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), degree of centrality (DC) and regional homogeneity (ReHo) were derived from rs-fMRI data. These data were registered against a pain-ROI atlas. The following clinical pain scores were assessed in the same five patients: Numerical Pain Rating Scale (NPRS), Visual Analogue Scale (VAS), Central Sensitization Inventory (CSI), Oswestry Disability Index (ODI), Pain Catastrophizing Scale (PCS), Pittsburgh Sleep Quality Index (PSQI) and Hospital Anxiety and Depression Scale (HADS). Predictive linear associations between pain ROIs and clinical scores were investigated using linear regression. RESULTS: Significant linear associations (p-value < 0.001) were found between pCASL-derived ATT to the dorsolateral prefrontal cortex (DLPC) and the NPRS; CBF to the ventral posterolateral thalamus (VPL) and the VAS, and of the posterior cingulate cortex (PCC) and the VAS; CBV of the posterior short gyrus (PS) and the VAS; and rs-fMRI-derived fALFF of the amygdala and the CSI. CONCLUSIONS: A comparison of functional imaging results and clinical pain scores suggest predictive relationships between resting-state function/brain perfusion in regions involved in pain perception and processing and various clinical pain assessments.