The Central Sensitization Inventory (CSI): …

1 The Central Sensitization Inventory (CSI): EstablishingClinically-Significant Values for Identifying Central SensitivitySyndromes in an Outpatient Chronic Pain SampleRandy Neblett,*Howard Cohen,yYunHee Choi,*Meredith M. Hartzell,*Mark Williams,*Tom G. Mayer,zand Robert J. Gatchelx*PRIDE Research Foundation, Dallas, School of Nursing, The University of Texas at Arlington, and Associate Medical Director, PRIDE, Dallas, of Orthopedic Surgery, University of Texas Southwestern Medical Center at Dallas, Dallas, of Psychology, The University of Texas at Arlington, Arlington, : Central Sensitization (CS) is a proposed physiological phenomenon in which Central ner-vous system neurons become hyperexcitable, resulting in hypersensitivity to both noxious and non-noxious stimuli.

2 The term Central sensitivity syndrome (CSS) describes a group of medically indistinct(or nonspecific) disorders, such as fibromyalgia, chronic fatigue syndrome, and irritable bowel syn-drome, for which CS may be a common etiology. In a previous study, the Central Sensitization inven-tory (CSI) was introduced as a screening instrument for clinicians to help identify patients with a was found to have high reliability and validity (test-retest reliability = .82; Cronbach s alpha = .88).The present study investigated a cohort of 121 patients who were referred to a multidisciplinary paincenter, which specializes in the assessment and treatment of complex pain and psychophysiologicaldisorders, including CSSs. A large percentage of patients (n = 89, 74%) met clinical criteria for one ormore CSSs, and CSI scores were positively correlated with the number of diagnosed CSSs.

3 A receiveroperating characteristic analysis determined that a CSI score of 40 out of 100 best distinguished be-tween the CSS patient group and a nonpatient comparison sample (N = 129) (area under thecurve = .86, sensitivity = 81%, specificity = 75%).Perspective:The CSI is a new self-report screening instrument to help identify patients with CSSs,including fibromyalgia. The present study investigated CSI scores in a heterogeneous pain popula-tion, with a large percentage of CSSs, and a normative nonclinical sample to determine a clinicallyrelevant cutoff value. 2013 by the American Pain SocietyKey words: Central Sensitization Inventory (CSI), Central sensitivity syndrome, fibromyalgia, chronicwidespread pain, irritable bowel Sensitization (CS)is a proposed physiologicalphenomenon in which dysregulation in the centralnervous system causes neuronal dysregulation andhyperexcitability, resultinginhypersensitivitytobothnoxious and non-noxious stimuli.

4 The presence of CS hasbeen demonstrated in Central sensitivity syndrome (CSS)populations by comparing the pain thresholds of CSSpatients to the thresholds of pain-free controls to variousstimuli (such as electrical, pressure, cold, and heat). Objec-tive measures of CS, which complement subjectiveself-report, include brain imaging and nociceptive spinalreflex ,25,43CS is associated with allodynia,hyperalgesia (excessive sensitivity to a normally painfulstimulus), expansion of the receptive field (pain extendingbeyond the area of peripheral nerve supply), andunusually prolonged pain after a painful stimulus hasbeen removed (usually throbbing, burning, tingling, ornumbness).44CS has been proposed as the root etiologyfor CSSs,15,30,41which refer to a group of medicallyindistinct disorders for which no organic cause can beReceived August 16, 2012; Revised November 6, 2012; AcceptedNovember 27, paper has, in part, been possible by a grant from the National Insti-tutes of Health (1UO1 DEO10713-12A2).

5 This manuscript was prepared without other financial support and withno support of any kind that may represent a possible conflict of reprint requests to Tom G. Mayer, MD, 5701 Maple Ave. #100,Dallas, TX 75235. 2013 by the American Pain Journal of Pain, Vol-,No-(-), 2013: pp 1-8 Available online ,30,40-42 These include fibromyalgia, chronicfatigue syndrome, irritable bowel syndrome (IBS),temporomandibular joint disorder (TMD), and tensionheadache/migraine, among others. These CSSs are highlyintercorrelated, share many common symptoms, includingpain, and demonstrate evidence of ,42In addition to these previously mentioned core CSSs,other pain-related disorders, often viewed as peripheralpain disorders, may also fit into the CSS family or sharesome degree of CS.

6 For instance, although myofascialpain syndrome is less interrelated with other CSSs, andperipheral pain mechanisms have been implicated, re-duced pain thresholds to a variety of stimuli (suggestingthe presence of CS) have been identified in this popula-tion in a number of ,11,21,42 The presence of CS,and associations with other CSSs, have also been foundin other disorders in which pain is not a primarysymptom, such as restless leg syndrome2,33andposttraumatic stress disorder (PTSD).5,26A list ofproposed CSSs,15,42which were analyzed in the currentstudy, is presented inTable , a new comprehensive self-report Inventory ,the Central Sensitization Inventory (CSI), was developedto assess the overlapping symptom dimensions measure is intended as a screening instru-ment to help identify the presence of a CSS and to alertclinicians that presenting symptoms may be related ,effort,and resourcesare oftenspent onsuper-fluous diagnostic testing (such as colonoscopy, cardiaccatheterizations, or imaging) and surgical proceduresor implantable devices for patients with CSSs, when lessexpensive, alternative interventions (such as cognitive-behavioral and physical therapies)

7 May be more effectivefor this ,16,37,39 Part A of the CSI assesses 25health-related symptoms that are common to CSSs, withtotal scores ranging from 0 to 100. Part B (which is notscored) asks if one has previously been diagnosed with1 or more specific disorders, including 7 separate its initial comprehensive evaluation,18the CSI wasfound to be psychometrically sound, with a highdegree of test-retest reliability and internal consistency(Pearson s r = .817; Cronbach s alpha = .879). Evaluationof the construct validity of the CSI in 4 samples (3 withina work-related injury population and 1 nonclinicalnormative sample) confirmed that fibromyalgia patients(with increased tenderness to palpation, suggesting themost CS) scored the highest on the CSI; chronic wide-spread pain patients, without fibromyalgia (with less ten-derness to palpation, suggesting less CS), and chronic lowback pain patients (without chronic widespread pain,suggesting less CS) scored somewhat lower; and the non-clinical normative population (with presumably minimalto no CS) scored the lowest (P<.)

8 05).The goals of the present study were 3-fold: 1) to deter-mine if CSI scores are associated with the presence of 1 ormore CSSs in a group of patients seeking outpatientmultidisciplinary pain management treatment; 2) todetermine if the self-reported diagnoses on Part B ofthe CSI correspond with actual physician diagnosis; and3) to establish a clinically relevant cutoff score forpredicting the presence of a CSS, using a receiver operat-ing characteristic (ROC) were collected from 268 consecutive patientsreferred to an interdisciplinary pain clinic specializing inthe assessment and treatment of complex pain and psy-chophysiological disorders, including CSSs. Eighteen pa-tients were eliminated from the total sample based onthe following exclusion criteria: 1) age over 70 and/or 2)diagnosis of specific medical conditions that can nega-tively affect the Central nervous system, including cancer,brain or spinal cord injury, neurological disease or injury,and multiple sclerosis.

9 The remaining 250-subject totalsample was then randomly assigned to 2 groups of 121and 129 subjects, utilizing the approximately 50% ofall cases function in SPSS (SPSS, Inc, Armonk, NY).The first group of 121 subjects was used in this study toestablish a clinically relevant cutoff score for the CSI,and the second group of 129 subjects was used in anotherstudy. Of the 121 subjects used in the current study, 89(74%) were diagnosed with 1 or more arrival at the initial appointment, all patientscompleted a self-administered CSI as well as self-reported documentation of current and past symptomsand disorders. It should be noted that because all thedata used in the present study were part of the patients standard medical files, the study was granted exemptionfrom institutional review board review.

10 A comprehensiveinterview was conducted by a single psychiatrist ( )with extensive experience and training in the diagnosisof mental illness, chronic pain conditions, and , subjects were evaluated for presentingcomplaints, current and past medications, medical andpsychiatric history, and current medical and psychiatricdiagnosis, based upon all available diagnostic testsTable of CSSs (Diagnosed bya Physician) and CSI Scores in the CSS PatientSample (n = 89 [ ])DIAGNOSIS*N(%)CSIM (SD)Tension headache/migraines47 (39) ( )Myofascial pain syndrome47 (39) ( )Fibromyalgia38 (31) ( )Irritable bowel syndrome18 (15) ( )Temporomandibular joint disorder14 (12) ( )Posttraumatic stress disorder14 (12) ( )Adult onset10 ( ) ( )Childhood onset4 ( ) ( )Restless leg syndrome10 (8) ( )Chronic fatigue syndrome5 (4) ( )Interstitial cystitis5 (4) ( )Complex regional pain syndrome3 (2) ( )Multiple chemical sensitivity1 (1)75 ( )Abbreviations: M, mean; SD, standard deviation.