The Relationship Between Magnetic Resonance Imaging (MRI) Scores and Sensory Testing in Axial Spondyloarthritis

Investigation of the Relationship Between Sacroiliac Magnetic Resonance Imaging (MRI) Scores and Quantitative Sensory Testing in Patients With Axial Spondyloarthritis

Axial spondyloarthritis is one of the most common rheumatic diseases and chronic pain and morning stiffness are the main complaints of these patients. Central sensitization is defined as increased response to normal or sub-threshold stimuli of central nervous system and its close relationship with many rheumatological diseases has been demonstrated in several studies. There is no method for the diagnosis of central sensitization is accepted as a gold standard. The clinical scales and quantitative sensory testing (QST) widely is used for this purpose widely. The most commonly used QST types include pressure pain threshold (PPT), temporal summation (TS) and conditioned pain modulation (CPM). The well-known scale used for the evaluation of central sensitization is the Central Sensitization Inventory (CSI) , developed in 2011 for detect central sensitization in chronic pain patients. In this study, it was aimed to investigate the relationship between QST and CSI and sacroiliac MRI changes.

Central sensitization is hypersensitivity and increased response to normal/painless stimuli due to dysfunction in endogenous pain pathways. Quantitative sensory testing is frequently used to detect pain sensitization, and pressure pain threshold (PPT) and temporal summation (TS) are often preferred for this purpose. Recently, in addition to these methods, conditional pain modulation (CPM), in which descending pain pathways are tested, is also preferred. With PPT and TS measurement, local/generalized sensitivity increase can be detected in patients who develop pain sensitization. Observation of increased nociceptor response and decrease in pressure pain threshold in the tissue damaged area is interpreted in favor of peripheral sensitization, while obtaining a similar response in adjacent or distant areas is defined as generalized increased sensitivity. Although it is known that local hyperalgesia is one of the main findings of inflammation, studies that have shown this quantitatively are limited. Inflammatory lesions are observed in patients with axial spondyloarthritis, especially in the active stages of the disease, and the relationship of these lesions with PPT, TS and CPM values and pain sensitization is unknown. Therefore, in this study, it was planned to investigate the relationship of inflammatory and structural lesions detected by sacroiliac MRI with regional PPT,TS, CPM and pain sensitization in patients diagnosed with axSpA.

Inclusion Criteria:

• Diagnosed with axSpA according to the Assessment of SpondyloArthritis International Society (ASAS) criteria
• Aged between 18-65 years

Exclusion Criteria:

• Had an other rheumatic diseases, peripheral vascular disease, peripheral neuropathy and spine disease (e.g., symptomatic herniated disc, spinal stenosis),
• Using centrally acting pain medications (e.g., pregabaline, duloxetine, opioids) or glucocorticoids (>10 mg prednisone or its equivalent) within 3 months of study enrollment