Preliminary observations on cerebral blood flow and pain sensitivity in adults with SCD

Abstract Objectives SCD is characterized by chronic anemia, cerebral ischemia, and significant pain, including acute and chronic manifestations. Prior studies have highlighted a link between silent cerebral ischemia, elevated cerebral blood flow (CBF), and diminished fluid cognition. However, the relationship between CBF and pain sensitivity remains understudied. We hypothesized that increased CBF would be paradoxically associated with reduced pain sensitivity in SCD patients. Methods This cross-sectional study compared 7 SCD patients and 3 healthy controls (HCs). CBF was measured using arterial spin labeling, fluid cognition via NIH Toolbox assessments, and pain sensitivity using the Pain Sensitivity Questionnaire (PSQ), PainDETECT, and Brief Pain Inventory (BPI). Group differences were analyzed with t-tests, and relationships within SCD patients were assessed using Pearson correlation. Results SCD patients exhibited higher pain sensitivity compared to HCs across all measures (eg, PSQ Total: 5.05 ± 1.63 vs 2.31 ± 0.50, P = .004). Trends toward an inverse relationship between CBF and PSQ scores were observed (eg, PSQ Total, r = −0.7423, P = .0560), suggesting that increased CBF may modulate pain perception. No significant correlations were found between CBF and PainDETECT or BPI scores. Conclusions While SCD patients experience heightened pain sensitivity compared to HCs, increased CBF appears to reduce sensitivity to moderate pain, suggesting a preliminary association. between cerebral ischemia and pain perception. These findings underscore the need for further research into the mechanisms underlying pain modulation in SCD and the potential role of cerebral blood flow as a biomarker for personalized pain management. The findings in this study are exploratory and hypothesis-generating due to the small sample size.