Title:

The organisation of the stress response, and its relevance to chiropractors: a commentary.

Authors:

Katie Hardy, Henry Pollard

Date of completion: 20/12/05

Place of completion:

Sydney

College/Institution:

Macquarie University

Address correspondence to:

Email address: katie_hardy@hotmail.com

Abstract:

Background: The stress response is a natural reaction by the body, against potentially harmful stimuli to enhance the chance for survival. Persistent activation of the stress response can cause changes to homeostatic mechanisms. The study of stress neurophysiology, in the evaluation of the manifestation of disease in the body, suggests that these chronic changes have detrimental effects on sub cortical structures. Furthermore, there is much scientific support for the notion that chronic activation of supraspinal systems will lead to maladaptation of homeostatic mechanisms, causing the impairment of processes within the body, and ultimately leading to visceral disorders. The chiropractic profession for many years has alluded to chronic change of neurophysiological pathways as a potential explanation of visceral disorders, but the profession has typically described these in terms of somatovisceral or viscerosomatic reflex activity. Change in supraspinal neurophysiological efferent activity is increasingly being used to explain \"stress\" related disease. The chiropractic profession should consider investigating such stress responses by conducting spinal manipulative therapy trials that evaluate supraspinal effects of manipulation. Such research may help elucidate key mechanisms associated with the change of visceral disorders noted by some chiropractors following manipulative therapy.

Objective: Walter Canon offered the first model of homeostasis as the \"coordinated physiological processes which maintain most of the steady states in the organism\" [1-3], and further focused on the \"sympathetic nervous system as an essential homeostatic system that served to restore stress-induced disturbed homeostasis and to promote survival of the organism\". From work conducted during the 1930\'s to 1950\'s, Hans Selye introduced the concept of stress as a medical and scientific entity, depicting a pathological triad elicited by numerous stressors. Sleye then employed this defined theory of stress as \"the non-specific response of the body to any demand\" [4]. Selye proposed that the human body had a finite amount of adaptable energy, and opined that a stressor whether pleasant or not, was irrelevant because any type of stress required adaptation to manifest. The important criterion was the intensity of the demand, and whether the body could meet that demand with an appropriate response. This cognitive response came to be known as the \"fight-or-flight\" response [5] and involved the activation of necessary physiological and behavioral responses for survival [6]. These responses are often referred to as \'stress responses\' and include the activation of the hypothalamic-pituitary-adrenal axis and sympatho-adrenal system, resulting in the consequential secretion of multiple hormones including corticotrophin releasing hormone, adrenocorticotropin hormone, cortisol, norepinephrine and epinephrine [7]. Once the stress response is activated, behavioral and physiological changes lead the way for the organism to adjust homeostasis within the body, and increase its chances for survival [8]. It is in times of sustained or repeated activation that the stress response may alter [7]. Due to the intricate nature of the above systems, systematic changes can cause dramatic effects on organs, which otherwise would be activated in advantage for the organism [9]. Repeated stimulation of hormones, and neurotransmitters may render target tissues resistant, instigating the cascade into disease and illness [10]. Many pathological processes, such as chronic pain disorders, immune disorders, cardiovascular disorders, metabolic disease and behaviour disorders, may be the result of chronic activation of the hypothalamo-pituitary-adrenal axis and sympatho-adrenal system, affecting tissues or biological pathways, contributing to the global nature of disease [11,12]. As stress becomes more prominent in society, trying to understand mechanisms with which it manifests in the body, and potential treatment for these manifestations is imperative to the development of effective chiropractic treatment strategies. This commentary attempts to address the development of disease within in the body due to chronic stress activation. It discusses the anatomy, physiology and the relationship of adverse chronic stress activation on systems within the body. This is followed by discussion of how these variables integrate and are potentially affected by the application of manipulative therapy.

Methods: -

Results: -

Conclusions: Sufficient evidence exists to consider stress and its mechanism, in the generation of diseases often seen by chiropractors. To date little investigation of this potential mechanism of disease and treatment has been conducted by the chiropractic profession. In a time when peak chiropractic organizations are calling for a mind-body approach to the management of chronic musculoskeletal and non – musculoskeletal disease [165], due consideration of the body of neurobiological evidence that supports the broadening of the operating paradigm within chiropractic seems warranted. Despite the call for a broadening of approaches and the embrace of such approaches by groups within chiropractic, it appears the threat to the dominant paradigm appears too great for most to adapt. The profession should consider more closely the emerging areas of study such as psychoneuroimmunology and how the development of that literature actually supports a broadening of the dominant mechanistic paradigm to reflect recent advances in science.