Detecting the Emergence of Chronic Pain in Sickle Cell Disease

Abstract

Context Sickle cell disease (SCD) is an inherited hematological disease marked by intense pain. Early in life the pain is episodic, but it becomes increasingly chronic in many cases. Little is known about this emergence of a chronic pain state. Objectives The goal of this study was to determine whether adult SCD patients whose pain is still largely episodic show early signs of the disturbed pain processing (hyperalgesia, increased temporal summation) and cognition (hypervigilance and catastrophizing) that are characteristic of a chronic pain state. Methods SCD patients (n=22) and healthy controls (n=52) received noxious pressure stimulation for up to three minutes, and periodically reported pain intensity and unpleasantness on 0–10 scales, allowing the rate of pain increase (temporal summation) to be determined. Pain intensity discrimination also was measured, and attitudes toward pain were assessed. Results There were no overall differences in pain ratings or temporal summation between patient and control groups. However, patients’ experimental pain ratings tended to increase with age, and those reporting a history of very painful episodes showed particularly rapid temporal summation of pain unpleasantness. Patients were significantly impaired at discriminating intensities of noxious stimulation. Patients were more hypervigilant than controls, but catastrophizing was elevated only during pain episodes. Conclusion Most SCD patients whose pain remits entirely between episodes are not in a chronic pain state, but some—those who are older and have a history of highly painful episodes—appear to be transitioning into it. These early signs of disturbed processing may aid clinicians seeking to forestall disease progression.

Early insights into the neurobiology of pain in sickle cell disease: A systematic review of the literature

“…[13-17] QST is psychophysical testing used to evaluate the sensitivity of the somatosensory system in humans with a specific focus on thermal (heat, cold) and mechanical (pressure) sensitivity. QST can detect sensory loss (hyposensitivity) or gain (hypersensitivity) through the evaluation of two different thresholds called detection thresholds and pain thresholds.…”

“…[13] In a related study using different methodology, Hollins et al evaluated whether increased temporal summation occurred in patients with SCD compared to healthy African American controls. [17] Temporal summation is defined as an increase in the intensity and unpleasantness of pain that is provoked by a noxious stimulus that is constantly applied and provides supporting evidence for central sensitization. This study used constant pressure as the noxious stimulus and did not assess heat or cold stimuli.…”

“…“pain builds up rapidly”). [17] The variability of findings in these studies underscore the challenges of studying pain in patients with SCD due to the immense phenotypic variability that likely manifests with different pain features. Furthermore, the variability in these data when patients were tested in their baseline state provides strong rationale for the need to study the sensory abnormalities in patients with SCD during an acute pain event.…”

Sickle Cell Disease Patients With and Without Extremely High Hospital Use: Pain, Opioids, and Coping

“…7 Providers only may see ''the tip of the iceberg'' 8 of SCD pain and underestimate its severity because of the frequency; patients with SCD report variety in pain 9 and on more than 50% of days. 10 As patients with SCD age, acute episodic pain 11,12 may develop into a multidimensional chronic pain syndrome punctuated by acute episodes, 13,14 distinguishing SCD from many other conditions associated with chronic pain. 15 Evidence of the association between incidence of addiction and prescription of opioid pain management for SCD patients, especially patients with EHHU, is scant.…”

Subliminal (latent) processing of pain and its evolution to conscious awareness

“…Classic clinical examples include sickle cell disease (SCD) (Niscola et al, 2009) and episodic migraine , where repeated episodic crises in SCD may emerge into a chronic pain state (Hollins et al, 2012) and the progression of migraine frequency, from episodic migraine into chronic migraine (Bigal and Lipton, 2008a; May and Schulte, 2016). In both cases, summation of repeated attacks affecting or involving afferent sensory systems may induce brain changes leading to a cascade that presents with a chronic pain condition.…”