Reply to Jensen, O.K. On the Use of Quantitative Sensory Testing to Estimate Central Sensitization in Humans. Comment on "Schuttert et al. The Definition, Assessment, and Prevalence of (Human Assumed) Central Sensitisation in Patients with Chronic Low Back Pain: A Systematic Review. J. Clin. Med. 2021, 10, 5931".

We thank Dr. Jensen for his interest [...].

The Definition, Assessment, and Prevalence of (Human Assumed) Central Sensitisation in Patients with Chronic Low Back Pain: A Systematic Review.

Central sensitisation is assumed to be one of the underlying mechanisms for chronic low back pain. Because central sensitisation is not directly assessable in humans, the term 'human assumed central sensitisation' (HACS) is suggested. The objectives were to investigate what definitions for HACS have been used, to evaluate the methods to assess HACS, to assess the validity of those methods, and to estimate the prevalence of HACS. Database search resulted in 34 included studies. Forty different definition references were used to define HACS. This review uncovered twenty quantitative methods to assess HACS, including four questionnaires and sixteen quantitative sensory testing measures. The prevalence of HACS in patients with chronic low back pain was estimated in three studies. The current systematic review highlights that multiple definitions, assessment methods, and prevalence estimates are stated in the literature regarding HACS in patients with chronic low back pain. Most of the assessment methods of HACS are not validated but have been tested for reliability and repeatability. Given the lack of a gold standard to assess HACS, an initial grading system is proposed to standardize clinical and research assessments of HACS in patients with a chronic low back.

Assessment of conditioned pain modulation in healthy participants and patients with chronic pain: manifestations and implications for pain progression.

PURPOSE OF REVIEW: The purpose of this review is to summarize recent findings on conditioned pain modulation (CPM) in humans with a focus on methodology, factors modulating CPM, and the potential for CPM as a clinical marker for pain progression. RECENT FINDINGS: CPM can be evoked by combining different stimulus modalities with good reliability; sequential CPM effects are stable over time with limited carryover effects. Optimism and pain catastrophizing might influence pain inhibition. Further, studies suggest that the CPM effect can be improved by gabapentinoids, transcranial direct current stimulation to cortical structures, and exercise and that long-term opioid use might impair CPM in patients with chronic pain. Clinical evidence suggests that preoperative impaired CPM may predict more severe chronic postoperative pain. The effect of pain duration on CPM impairment has been challenged by recent studies. SUMMARY: As CPM methodology is optimized, studies are revealing factors that can modulate descending pain inhibitory pathways. Understanding underlying mechanisms of CPM will improve the utility of CPM in a clinical setting and potentially lead to personalized treatments for chronic pain patients.

Review article: Best practice management of neck pain in the emergency department (part 6 of the musculoskeletal injuries rapid review series).

Neck pain and whiplash injuries are a common presentation to the ED, and a frequent cause of disability globally. This rapid review investigated best practice for the assessment and management of musculoskeletal neck pain in the ED. PubMed, CINAHL, EMBASE, TRIP and the grey literature, including relevant organisational websites, were searched in 2017. Primary studies, systematic reviews and guidelines were considered for inclusion. English-language articles published in the past 12 years addressing acute neck pain assessment, management or prognosis in the ED were included. Data extraction was conducted, followed by quality appraisal to rate levels of evidence where possible. The search revealed 2080 articles, of which 51 were included (n = 22 primary articles, n = 13 systematic reviews and n = 16 guidelines). Consistent evidence was found to support the use of 'red flags' to screen for serious pathologies, judicious use of imaging through clinical decision rule application and promotion of functional exercise coupled with advice and reassurance. Clinicians may also consider applying risk-stratification methods, such as using a clinical prediction rule, to guide patient discharge and referral plans; however, the evidence is still emerging in this population. This rapid review provides clinicians managing neck pain in the ED a summary of the best available evidence to enhance quality of care and optimise patient outcomes.