Somatosensation in OA: exploring the relationships of pain sensitization, vibratory perception and spontaneous pain

Anisha B Dua,Tuhina Neogi,Rachel A Mikolaitis,Joel A Block,Najia Shakoor

doi:10.1186/s12891-018-2206-4

Abstract

BackgroundPain in osteoarthritis (OA) remains poorly understood. Different types of somatosensory alterations exist in OA including hyperesthesia and increased sensitivity to painful stimuli as well as those of decreased sensitivity to cutaneous stimuli including vibratory perception threshold. The relationship between these different somatosensory measures has not been previously evaluated in OA. In this observational study, we evaluated relationships between vibratory perception (VPT), pressure pain detection thresholds (PPT), allodynia and subjective pain in knee OA.MethodsForty-two persons with moderate to severe knee OA and 12 controls without OA were evaluated. VPT was measured using a biothesiometer. Allodynia was measured by application of a 60 g Von Frey monofilament repeatedly to predetermined sites. PPTs were measured using a pressure algometer.ResultsIncreased vibratory acuity was associated with lower PPTs and presence of allodynia. Allodynia was more common in OA than controls (54.8% vs 16.6%, p = 0.024 in the ipsilateral knee, and 42.9% vs 0%, p = 0.005 in the contralateral knee). OA participants with allodynia had lower PPTs than those without allodynia. In those with OA, spontaneous knee pain was associated with lower PPTs and with allodynia.ConclusionThis study confirms the presence of somatosensory alterations in OA. Sensory alterations (vibratory perception) were shown to be related to nociceptive alterations (sensitization) in OA, showing a general increased sensitivity to cutaneous mechanical stimulation. Understanding these relationships is an important step in delineating the complicated pathophysiology of pain processing in OA.

Highlights

Pain in osteoarthritis (OA) remains poorly understood
We have previously shown that subjects with knee OA and hip OA have generalized vibratory sense deficits with impaired vibratory perception threshold (VPT) at both the upper and lower extremities compared to age-matched control subjects [14, 15]
Central and peripheral sensitization, which are due to alterations in central and peripheral pain processing resulting in allodynia and hyperalgesia [6], have been increasingly recognized as a potential contributor to the experience of pain in those with knee OA

Summary

Introduction

Different types of somatosensory alterations exist in OA including hyperesthesia and increased sensitivity to painful stimuli as well as those of decreased sensitivity to cutaneous stimuli including vibratory perception threshold. The relationship between these different somatosensory measures has not been previously evaluated in OA. In this observational study, we evaluated relationships between vibratory perception (VPT), pressure pain detection thresholds (PPT), allodynia and subjective pain in knee OA. Previous studies of symptomatic knee OA have demonstrated findings suggestive of sensitization or heightened pain sensitivity, including lower pressure pain thresholds (PPT) and the presence of mechanical allodynia [8, 10,11,12]

Methods

Results

Discussion

Conclusion