Physical Exam and Self-Reported Pain outcomes from a Randomized Trial on Chronic Cervicogenic Headache

1. Physical Exam and Self-Reported Pain outcomes from a Randomized Trial on Chronic Cervicogenic Headache Darcy Vavrek ND MS1 Mitch Haas DC MA1 Dave Peterson DC1 1Western States Chiropractic College, Portland Oregon Funded by NCCAM NIH R21AT002324

2. Cervicogenic headache (CHA) • Cervicogenic headache (CHA) is a type of headache causally associated with cervical myofascial tender spots combined with cervical spine dysfunction. • (Headache Classification Subcommittee of the International Headache Society 2004) • The reported prevalence of CHA varies from 13.8% to 17.8% of the headache population in different epidemiological studies. • (Anthony 2000, Nilsson 1995, Pfaffenrath 1990) Western States Chiropractic College

3. Spinal Manipulative Therapy and CHA • The scientific evidence on SMT for the relief of chronic headache has been well discussed in systematic reviews of randomized trials. • (Hurwitz 1996, Vernon 1999, Bronfort 2001, Astin 2002, Bronfort 2004, Lenssinck 2004, Fernandez-de-Las-Penas 2005 & 2006) • These reviews looked at patient self-reported outcomes when evaluating treatment effect such as pain intensity, headache index, frequency, duration, and improvement. • Missing were any objective outcomes that could be measured by the treating physician. Western States Chiropractic College

4. Objectives of analysis project • Headache pain studies use subject self-reported outcomes to assess treatment efficacy. • Objective clinical measures for studies of CHA pain have not been established. • What do objective physical measures reveal and how do they associate with self-reported outcomes? • In this analysis, we investigate relationships between objective physical exam measures with self-reported CHA outcomes. • Associations between PE and self-reported outcomes were evaluated using linear models, adjusting for socio-demographic differences and study group. Western States Chiropractic College

5. The RCT that generated the data • This is a secondary analysis of an open-label randomized controlled pilot study with 80 subjects randomized to 8 or 16 treatments of spinal manipulative therapy or light massage control over 8 weeks. • Forty of 80 subjects were randomized to 8 treatments (spinal manipulative therapy or light massage control) and 8 PE over 8 weeks. • Physical examinations by the study chiropractor served as an attention and physical contact control for the 40 subjects randomized to receive care once a week for 8 weeks. • The remaining subjects received no follow-up PE. Western States Chiropractic College

6. Subjective outcomes • Self-reported outcomes included • CHA and neck • Pain • Disability • Neck • Pain • Disability • Number of CHA headaches • Related CHA disability days Western States Chiropractic College

7. Physical Exam measures • Active cervical range of motion and associated pain • Motion palpation of the spine • cervical region • upper thoracic region • Algometric pain threshold evaluated over articular pillars/ transverse processes Western States Chiropractic College

8. Baseline summary • Participants tended to be young (37 ± 11), white, non-Hispanic (75%) women (78%). • There were notable differences in race and smoking at baseline • these will be used as covariates in the main analysis • There were no differences between group means in the subjective outcomes • The mean CHA pain intensity and functional disability were 54.0 and 48.3 respectively. • The sample averaged approximately fifteen CHAs per month • There were no clinically important differences between group means for physical exam outcomes Western States Chiropractic College

9. Baseline summary • Participants tended to have • cervical range of motion pain of 1.4 on a zero to ten pain scale • 20o of restricted extension cervical range of motion • 4 total endplay restrictions of some kind • pain pressure threshold of 3.2 kg • pain score from orthopedic tests for midline pain of 0.7 on a zero to ten pain scale • pain score of 1.1 across all ten point scale physical exam pain measures • Only two physical exam variables showed statistically significant differences between group means after adjusting for smoking and race • sitting rotation endplay restriction for C6-7 to C7-T1 left and right (p=.034 and .028 respectively). Western States Chiropractic College

10. Final outcome summary • While many physical exam measures showed a minor advantage of the SMT group over the LM group, on average, • there were only two PE measures whose mean treatment group differences were statistically significant. • Pain on Cervical ROM Right Rotation (mean difference 1.1, p=.025) • Pain on Cervical ROM Flexion (mean difference 1.1, p=.025) • Both these measures favor SMT after adjusting for race, smoking, and baseline physical exam measure. • Cervical ROM extension remains restricted in both groups by about 20o. Western States Chiropractic College

11. Final Outcome Summary • Also, there are some differences noted in subjective outcome group means reported in our paper submitted to Spine Journal. • (Haas – in review) • We decided to adjust for study treatment group as well as smoking and race in our main analysis models. Western States Chiropractic College

12. Results of Main Analysis • Cervical active ROM pain measures • were associated with neck pain intensity and disability, CHA frequency, and disability days at baseline. • Neck pain and disability • were not measured at weeks 4 & 8 • were no longer strongly associated at weeks 12 & 24 • Cervical active ROM measures • predicted CHA frequency and disability days well in the beginning, but this faded over time. • remained predictive of CHA frequency throughout study. • Sitting rotation endplay restriction • was associated with CHA frequency and disability days at baseline and faded over time. • Pain Pressure Threshold (PPT) • was associated with CHA pain and disability, neck pain and disability, CHA frequency and disability days at week 12 and moderately associated in surrounding weeks. • Compression tests for midline pain • were moderately associated with questionnaire outcomes with no clear pattern. • Distraction test associations • were limited by the fact that all participants score zero on their distraction test at their final physical exam. Western States Chiropractic College

13. Discussion • Physical exam measures of cervical ROM pain and net cervical ROM • were most associated with subjective headache experience near baseline, p<.001 to .038. • Pain pressure thresholds • were most associated with subjective outcomes at/after week 12, p=.001 to .035. • The pattern shifts at about week 12, four weeks after the final treatment Western States Chiropractic College

14. Cervical ROM • Cervical ROM and pain on cervical ROM might be expected to be more predictive for higher pain levels early on, since splinting may be an effect. • This association did not happen in all participants since, 11 out of 40 participants (~25%) reported no pain on cervical ROM at baseline. • Yet those who had pain on cervical ROM also had worse subjective outcomes at baseline. • Later on, with lower pain and some manual medicine related increased cervical ROM, cervical ROM and pain on cervical ROM would be expected to have a lesser relationship. • However, with the improvement of most study participants, zero pain reported on cervical ROM increased to 20 out of 40 participants (~50%) at their final physical exam • It is difficult to establish any type of linear relationship. • It is tempting to say that manipulation improved range of motion and the pain associated with range of motion and decreased the subject’s headaches because manipulation is directed at improving joint mobility and function. • However, both treatment groups improved with time and we were not powered to detect this type of effect. • Future studies that include cervical range of motion and associated pain as baseline and final secondary outcomes in a study, measured by a blinded study physician, will allow clinicians to address these unanswered questions. Western States Chiropractic College

15. Pain Pressure Threshold • The fact that pain pressure threshold is not a good baseline predictor of baseline subjective outcomes in our subject population is puzzling. • At 12 weeks, pressure over paraspinal soft tissues and over the joints was perhaps more associated with persistent headache outcomes because other musculoskeletal components associated with the neck pain and headaches were not fully affected by thrust manipulation which potentially has more therapeutic effect on joint mobility. • Yet, we were underpowered to detect this type of result and both treatment groups experienced this change in association. • Still, for the practicing clinician, it is likely that those with a low pain pressure threshold may also have worse subjective experiences and thus be candidates for further manual care. Western States Chiropractic College

16. No potential surrogates noted • No one physical exam measure remained predictive of the self-reported headache discomfort questions over time. • This is likely due to patient improvement. • Thus, no single objective physical exam surrogate measure for CHA clinical research is suggested by this study as a useful longitudinal outcome. • Further analysis of the data will assess if these baseline physical exam measures are predictive of treatment outcome. Western States Chiropractic College

17. Cervical extension • Both groups remained restricted on cervical extension after treatment, 20o restriction on average. • Perhaps decreased cervical ROM on extension is indicative of the population of those who might suffer from chronic cervicogenic headaches and could be a future focus of treatment assessment. Western States Chiropractic College

18. Limitations • Blinding • Treating physicians performing the attention control physical exam • were not blinded to treatment arm after baseline • could have performed biased assessment • may have expected improvement based on • time in the study • treatment group assignment. • Small sample, 20 patients per treatment arm. • Minimal power to detect the associations we’ve looked for • Results need to be repeated by larger studies • To further flush out the pathophysiology of cervicogenic headache. • Physical exam variables could be a secondary outcome Western States Chiropractic College

19. Limitations • Generalizability • Subjects • selected by rigid randomized clinical trial protocol • enrolled in the study went through • a phone screen • two baseline exams • had to meet study criteria before enrollment • Larger clinical trials on headache populations that gather longitudinal physical exam data will help to establish the generalizability of these results. Western States Chiropractic College

20. Conclusions • We noted that provocative cervical ROM pain was most predictive of the baseline headache experience. • However, 4 weeks after treatment, algometric pain thresholds were most predictive. • No one PE measure remained predictive of the self-reported headache outcomes over time. • Clinically important changes over time were observed in physical exam indicators for self-reported CHA pain and disability outcomes. • This is an important step towards establishing objective measures of CHA pain and disability for clinical studies. Western States Chiropractic College

21. References • Anthony M. Cervicogenic headache: Prevalence and response to local steroid therapy. Clin Exp Rheumatol. 2000; 18:S59-64. • Astin JA, Ernst E. The effectiveness of spinal manipulation for the treatment of headache disorders: A systematic review of randomized clinical trials. Cephalalgia. 2002;22:617-623. • Bronfort G, Assendelft WJ, Evans R, Haas M, Bouter L. Efficacy of spinal manipulation for chronic headache: A systematic review. J Manipulative Physiol Ther. 2001;24:457-466. • Bronfort G, Nilsson N, Haas M, et al. Non-invasive physical treatments for chronic/recurrent headache. Cochrane Database Syst Rev. 2004;(3):CD001878. • Fernandez-de-Las-Penas C, Alonso-Blanco C, Cuadrado ML, Miangolarra JC, Barriga FJ, Pareja JA. Are manual therapies effective in reducing pain from tension-type headache?: A systematic review. Clin J Pain. 2006;22:278-285. • Fernandez-de-Las-Penas C, Alonso-Blanco C, Cuadrado ML, Pareja JA. Spinal manipulative therapy in the management of cervicogenic headache. Headache. 2005;45:1260-1263. • Haas M, Spegman A, Peterson DH, Aickin M, Vavrek D. Dose-response and efficacy of spinal manipulation for chronic cervicogenic headache. Spine Journal. (in review). • Headache Classification Subcommittee of the International Headache Society. The international classification of headache disorders, 2nd edition. Cephalalgia. 2004; 24:8-160. Available from: • Hurwitz EL, Aker PD, Adams AH, Meeker WC, Shekelle PG. Manipulation and mobilization of the cervical spine. A systematic review of the literature. Spine. 1996;21:1746-59; discussion 1759-60. • Lenssinck ML, Damen L, Verhagen AP, Berger MY, Passchier J, Koes BW. The effectiveness of physiotherapy and manipulation in patients with tension-type headache: A systematic review. Pain. 2004;112:381-388. • Nilsson N. The prevalence of cervicogenic headache in a random population sample of 20-59 year olds. Spine. 1995; 20:1884-1888. • Pfaffenrath V, Kaube H. Diagnostics of cervicogenic headache. Funct Neurol. 1990; 5:159-164. • Vernon H, McDermaid CS, Hagino C. Systematic review of randomized clinical trials of complementary/alternative therapies in the treatment of tension-type and cervicogenic headache. Complement Ther Med. 1999;7:142-155. Western States Chiropractic College