Spinal Manipulation Therapy Effect on Somato-Sympathetic Reflexes
Desmarais A, Descarreaux M, Houle S, Piché M. Tuning the gain of somato-sympathetic reflexes by stimulation of the thoracic spine in humans. Neurosci Lett.2011;490(2):107-111.
It has long been taught in osteopathic medical education that osteopathic manipulative treatment for thoracic somatic dysfunction is beneficial for decreasing sympathetic neural activity in related spinal levels; however, research proving this relationship is lacking. Researchers at the Université du Québec à Trois-Rivières reported on the results of a novel research design that explored whether spinal manipulation therapy (SMT) in the upper thoracic region of healthy humans can attenuate skin conductance responses (SCR), a measure of sympathetic nerve activity, in the plantar and palmar skin. The researchers applied a standard heat stimulus to the thoracic spine in addition to an electrical phasic stimulus from the lower extremity. Recall that sudomotor activity to the palms is controlled by sympathetic preganglionic cell bodies in the spinal cord between thoracic segments T2-T6. The plantar SCR is governed by sympathetic preganglionic cell bodies in spinal levels T10-L2.
Twenty-three healthy people (13 males and 10 females) were recruited, but only 17 participants were included for all analyses (10 males and 7 females; mean age [standard error of the mean], 25.0 [1.1]) as a result of dropouts. Participants were tested in the prone position on 4 separate days for about an hour per session. The sural nerve was stimulated according to a standard protocol while palmar and plantar SCR were recorded. A clear stimulus-response relationship was established. Another stimulus with a noxious heating probe was applied to the upper thoracic skin over the spine between the T3-T5 vertebrae to evaluate whether this segmental stimulus could alter the response to the distal phasic stimulus from the lower extremity. The temperature was adjusted to cause moderate pain stimulus for 2 minutes. The SMT stimulus, consisting of a single high-velocity, low-amplitude thrust, was applied by an experienced chiropractor at T4. The audible popping sound of joint cavitation was noted as an indication of successful stimulus with the SMT. Spinal manipulation therapy was applied with the phasic electronic stimulus from the lower extremity in 1 session and in conjunction with the heat stimulus in another session.
The noxious heat stimulus increased the amplitude of the palmar SCR, but the SMT decreased it (P<.001). The plantar SCR did not change significantly with either stimulus (P=.42). Spinal manipulation therapy prevented the increase in palmar SCR from the heat stimulus when applied immediately prior to the heat stimulus. Participant pain, anxiety, and respiration frequency were measured to assess for potential confounding influence on the results but were found not to be responsible for the attenuation seen in the palmar SCR.
The authors concluded that “somatic stimulation of the thoracic spine may modulate somato-sympathetic reflexes segmentally in conscious, healthy volunteers.” This finding lends support to the theory that SMT affects sympathetic nerve activity in segmentally related spinal levels.
The researchers were not able to distinguish the mechanism underlying the effects seen after high-velocity, low-amplitude SMT. For example, this study did not assess whether the effects seen were from stimulation or inhibition of skin, muscle, joint, or other neuroreceptors or chemical receptors. Future studies should continue along this line of thought to determine which mechanisms are responsible for this effect. Additionally, symptomatic individuals may respond differently and should be compared to non-symptomatic individuals.—M.A.S.
© 2012 The American Osteopathic Association
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
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- Prediction of Osteopathic Medical School Performance on the Basis of MCAT Score, GPA, Sex, Undergraduate Major, and Undergraduate Institution
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- AOA Communication
- Continuous Development and Review of AOA COCA Standards and Procedures
- Osteopathic Graduate Medical Education 2012
- Evolving Role of Osteopathic Postdoctoral Training Institutions
- AOA Continuing Medical Education
- Changes to Osteopathic Specialty Board Certification
- Appendix 1. Colleges of Osteopathic Medicine in the United States
- Special Communication
- Appendix 2. Figures from AACOM's Trends in Osteopathic Medical School Applicants, Enrollment and Graduates.
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- CME Quiz Answers
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Articles in the same Issue
- The Somatic Connection
- Intraoral Manipulation and Jaw Exercises Shown to Be of Benefit in Temporomandibular Joint Disorder
- Spinal Manipulation and Home Exercise Improve Neck Pain
- Spinal Manipulation Therapy Effect on Somato-Sympathetic Reflexes
- What Price Glamour? It's All About the Shoes!
- Special Report
- Advisory Committee on Immunization Practices (ACIP) Update, February 2012
- Editorial
- The Problem With Graduate Medical Education
- Medical Education
- Successful Implementation of New Osteopathic Graduate Medical Education Programs in a Community Hospital: Challenges and Lessons Learned
- Prediction of Osteopathic Medical School Performance on the Basis of MCAT Score, GPA, Sex, Undergraduate Major, and Undergraduate Institution
- Trainer-to-Student Ratios for Teaching Psychomotor Skills in Health Care Fields, as Applied to Osteopathic Manipulative Medicine
- AOA Communication
- Continuous Development and Review of AOA COCA Standards and Procedures
- Osteopathic Graduate Medical Education 2012
- Evolving Role of Osteopathic Postdoctoral Training Institutions
- AOA Continuing Medical Education
- Changes to Osteopathic Specialty Board Certification
- Appendix 1. Colleges of Osteopathic Medicine in the United States
- Special Communication
- Appendix 2. Figures from AACOM's Trends in Osteopathic Medical School Applicants, Enrollment and Graduates.
- Clinical Images
- Ecthyma Gangrenosum Caused by Psedumonas aeruginosa
- CME Quiz Answers
- CME Quiz Answers
