Investigation of Central Sensitization Frequency and Related Factors in Axial Spondyloarthritis Patients
Condition: Axial Spondyloarthritis; Central Sensitisation
MeSH terms: Spondylitis; Spondylarthritis; Axial Spondyloarthritis
Study type: Observational

Summary: 
      The term axial spondyloarthritis (axSpA) describes a group of chronic inflammatory diseases
      that characterized with spinal involvement. AxSpA 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. Pain in axSpA patients is generally considered as a result
      of increased inflammatory burden and structural changes, However, failure to adequate
      analgesia in every patient whose inflammation is suppressed with anti-inflammatory treatment
      suggests new pain mechanisms. Central sensitization (CS) is one of these mechanisms and its
      recognition is only possible by detailed evaluation of the patient. There is no method for
      the diagnosis of central sensitization is accepted as a gold standard. 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 , developed by Mayer et.al in 2011 for detect central
      sensitization in chronic pain patients. The aim of this study is to evaluate the frequency of
      central sensitization (CS) in patients with axSpA by means of clinical scales and
      quantitative sensory testing (QST), to examine related comorbidities and the parameters
      associated with the development of sensitization in these patients.
    

Detailed description: 
      The term axial spondyloarthritis (axSpA) describes a group of chronic inflammatory diseases
      that characterized with spinal involvement. AxSpA is one of the most common rheumatic
      diseases and chronic pain and morning stiffness are the main complaints of these patients.
      Central sensitization (CS) 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. However, data associated with central
      sensitization in axSpA patients is very limited. The quantitative sensory testing (QST) is
      commonly used for detection hyperalgesia and allodynia those are accepted main findings in
      sensitized patients. The most commonly used QST types include pressure pain threshold (PPT),
      temporal summation (TS) and conditioned pain modulation (CPM).Pressure pain threshold
      measurement is frequently used to show local / generalized sensitivity increase in patients
      who develop pain sensitization. For this purpose, the pain response of superficial or deep
      tissue can be evaluated through mechanical device called algometer. The algometer probe was
      placed vertically in the each selected point and pressure was increased until the participant
      reporting pressure became painful. The first pressure value at which pain is felt is
      considered the PPT of that point. TS is defined as a progressive increase in pain response
      with repetitive painful stimuli. This condition is also known as wind-up phenomenon and play
      a role to development CS. CPM, known as one of the main mechanisms of endogenous analgesia,
      is based on the principle that pain perception can be reduced with painful stimulus applied
      to different areas according to the "pain inhibits pain" model. In the CPM testing, it is
      aimed to investigate the modulator effect of two different painful stimuli on each other. The
      diagnosis of CS can be made with QST or with Central Sensitization Inventory (CSI). The aim
      of this study is to evaluate the frequency of central sensitization (CS) in patients with
      axial spondyloarthritis (AxSpA) by means of clinical scales and quantitative sensory testing
      (QST), to examine related comorbidities and the parameters associated with the development of
      sensitization in these patients. The patients with AxSpa and healthy controls will be
      included in this study. QST which consists of pressure pain threshold (PPT), temporal
      summation (TS) and conditioned pain modulation (CPM) will be applied to the patient and
      control groups. Disease activity (BASDAI), functional status (ASQoL, ILBPDI), sleep quality
      (PSQI), pain (VAS pain), depression (BDI) and fatigue (FSS) will be assessed. Fibromyalgia
      (FIRST) and other comorbidities will be investigated. Patients will be divided as the ones
      with and without CS according to the central sensitization inventory (CSI) and the results
      will be compared. After data collection, analysis will be performed with the appropriate
      statistical method
    

Intervention name(s): Pressure pain threshold; Temporal summation; Conditioned pain modulation; Central Sensitization Inventory; Bath Ankylosing Spondylitis Disease Activity Index; Ankylosing Spondylitis Quality of Life; Istanbul Low Back Pain Disability Index; Beck Depression Inventory; Fatigue Severity Scale; Pittsburgh Sleep Quality Index; Fibromyalgia Rapid Screening Tool; Visual analogue scale
Intervention type(s): Diagnostic Test; Diagnostic Test; Diagnostic Test; Diagnostic Test; Other; Other; Other; Other; Other; Other; Other; Other
Intervention description(s): The PPT assessments of spine will be performed over the spinous process and 2 cm right and left side of the corresponding spinous process. The regional PPT scores will be composed from sum of all PPT values for related segments at spine. The sacroiliac PPT scores will be obtained bilaterally from four measurement points; the first point is located 1 cm medially and caudally from spina iliaca posterior superior (SIPS) and 3 more laterally, medially and cranially.The left trapezius muscle will be used to evaluate distant control point .The 1 cm2 algometer probe will be placed vertically in the each selected point and pressure will be increased with 0.1 kg/sc until the participant reporting pressure became painful. The pressure value at which the pain is first felt will be accepted as the PPT of that point.; TS will be evaluated over the trapezius muscle, sacroiliac joints, C7, T6, and L3 levels at spine with manuel algometer. TS scores will be calculated for each spine level as the sum of three values which measured over the spinous process and 2 cm right and left side of corresponding level. In the evaluation of TS, a pressure as much the PPT value of each point will be applied with pain pressure algometer ten times with a 1-second interstimulus interval. Patients will be asked to rate their pain using on a 0 to 10 visual analogue scale (VAS) at 0, 5, and 10 seconds. TS will be calculated by subtracting the rating at 0 seconds from the rating at 10 seconds. The point that is located 1 cm medially and caudally from SIPS was used for SI joint TS measurement on both sides.; First stimulus will be applied to trapezius with the pressure that induced a pain intensity of 4 point on a 10 point VAS as called a test stimulus. After that the right hand of the patient will be immersed in 70C water for 20 seconds to create a conditioning stimulus. Second test stimulus with the same intensity of first one will be applied to trapezius after the conditioning stimulus and patients will be asked to rate their pain. If the patients cannot hold their hand in the water for 20 seconds, the test stimulus will be applied immediately after the patients removed their hands out of water. The ratio between the first and second VAS values multiplied by 100 will be defined as CPM score; Standardized questionnaire to determine the level of central sensitization; Standardized questionnaire to determine the level of disease activity in AxSpa patients; Standardized questionnaire to investigate the quality of life in AxSpa patients; Standardized questionnaire to investigate the disability; Standardized questionnaire to investigate the depression; Standardized questionnaire to investigate the fatigue; Standardized questionnaire to investigate the sleep quality and disturbance; Standardized questionnaire to detect fibromyalgia; global pain score on a 0 to 10
Other intervention name(s): PPT; TS; CPM; CSI; BASDAI; ASQoL; ILPBDI; BDI; FSS; PSQI; FIRST; VAS
Observational model: Case-Control
Time perspective: Cross-Sectional
Sampling method: Probability Sample
Study population: 
        The patients aged 18-65 years diagnosed with axSpA according to the ASAS criteria will be
        recruited from a Rheumatology outpatient clinic of a single tertiary care hospital
      
Keywords: Axial spondyloarthritis; central sensitization; quantitative sensory testing; central sensitization inventory