Central sensitization (CS), nociceptive hyper-excitability known to amplify and maintain clinical pain, has been identified as a leading culprit responsible for maintaining pain in several chronic pain conditions. Recent evidence suggests that it may explain differences in the symptom experience of individuals with sickle cell disease (SCD). Quantitative sensory testing (QST) can be used to examine CS and identify individuals that may have a heightened CS profile. The present study categorized patients with SCD based on QST responses into a high or low CS phenotype and compared these groups on measures of clinical pain, vaso-occlusive crises, psychosocial factors, and sleep continuity. Eighty-three adult patients with SCD completed QST, questionnaires, daily sleep and pain diaries over a three-month period, weekly phone calls for three months, and monthly phone calls for 12 months. Patients were divided into CS groups (i.e. No/Low CS [n=17] vs. High CS [n=21]), based on thermal and mechanical temporal summation and aftersensations, which were norm-referenced to 47 healthy controls. High CS subjects reported more clinical pain, vaso-occlusive crises, catastrophizing, and negative mood, and poorer sleep continuity (p’s<0.05) over the 18-month follow-up period. Future analyses should investigate whether psychosocial disturbances and sleep mediate the relationship between central sensitization and pain outcomes.
Perspective
In general, sickle cell disease patients with greater central sensitization had higher clinical pain, more crises, worse sleep, and more psychosocial disturbances compared to the low CS group.