Jacob Ablin MD
Tel Aviv Sourasky Medical Center, Israel
The story of fibromyalgia (FM) brings to mind Paul McCartney's epic lyrics – "the long and winding road". While some may still consider FM to be a new entity, somehow contrived by various forces and incentives, when looking back into history it becomes obvious that patients suffering from the constellation of symptoms which we currently designate to title "fibromyalgia syndrome" have been around all the time, whether recognized or not. Indeed, when examining the description of patients suffering from "neurasthenia" in the Nineteenth century, or from "colitis" in Axel Menthe's "The Story of San Michele" it is obvious that no matter what misconceptions were abundant at the time regarding both the nature of the problem, it's pathogenensis and its treatment, many patients suffering from such diagnoses would currently be identified as suffering from FM.
Notably, eminent Nineteenth century scholars such as George Beard associated neurasthenia with malfunction of the central nervous system , a concept not so far from the way we look at "central sensitization" a century and a half later. Subsequently however, medical thinking about the problem shifted and gyred with the introduction of the "fibrositis" title by William Gower in 1904 . While this term inherently implied the assumption of an underlying inflammatory etiology affecting connective tissue, a concept which subsequently fell out of favor, Gower did however direct attention at the possibility of fibrositis appearing as the results of physical trauma, such as the overturning of a tramcar, an etiological issue which continues to be discussed and debated to this very day.
Subsequently, over many decades, the fibrositis concept languished in a state of lack of interest. Despite the large numbers of individuals suffering from the clinical hallmarks of fibrositis/fibromyalgia, major medical textbooks paid little attention to the topic and students were usually instructed, either directly and/or by insinuation and innuendo, to regard the whole topic as somehow dubious, and definitely not very important.
The modern era of FM was ushered in at the last decade of the 20th Century, with the well – known ACR classification criteria published by Wolfe et al . These criteria, formulating the concept of FM as a chronic widespread pain syndrome characterized by diffuse musculoskeletal tenderness, had tremendous impact. Once criteria were established and officially endorsed by the prestigious rheumatology body, FM suddenly started to gain in legitimacy. Studies were initiated, patients recruited based on criteria, and an onslaught of publications appeared. In parallel, public awareness regarding the syndrome rapidly increased. All this happened despite the fact that the 1990 criteria have subsequently been recognized as in fact missing out on important clinical aspects of the FM syndrome, e.g. chronic fatigue, disturbed sleep etc. Intriguingly, while all this was happening, a gradual paradigm shift was evolving regarding the nature of FM. Initially, FM was regarded as a discrete illness, which one either had, based on criteira, or had not. Thus, a patient with 10 tender points did not have FM, despite suffering from chronic widespread pain, while one more tender point would establish the diagnosis. Moreover, based on this dichotomy, multiple studies examined the concept of comorbidity between FM and other "functional" disorders, reporting findings such as the frequent overlap between FM and Irritable Bowel Syndrome (IBS). However, over a relatively short period, FM came to considered more as a spectrum than as a yes-or-no condition and the concept of "central sensitization", denoting an increase in the gain of pain processing in the central nervous system  was first formulated and subsequently attributed to the pathogenesis of FM, as well as to other functional syndromes.
Current thinking regarding the FM concept has definitely come a long way. Over the last two decades, major progress has been made in the field of functional neuroimaging, allowing us for the first time to add objective meaning to the subjective heightened pain sensitivity classically described by patients. Starting with groundbreaking studies which showed that pain processing centers in the CNS of FM patients have a lower threshold for pain than in normal individuals  , subsequent research has delved into abnormal patterns of connectivity  and eventually led to an effort to develop a specific FM pain fingerprint with high specificity . Simultaneously, multiple studies have shed light on the genetic (as well as epigenetic) underpinnings of FM.
So, where is FM going to be in 10-20 or 30 years from today? Although it's hard to tell, it seems safe to assume that a lot will change. Similar to other complex CNS conditions, the understanding of FM is likely to become ever more complicated and multi – leveled. In the future, a strive towards precision medicine is likely to include the creation of a matrix of novel parameters for each patient, profiling individuals on the basis of multiple parameters such as genetic mapping, functional connectivity, psychosocial factors etc. This is also likely to lead to novel sub classifications of the large group of patients currently collectively labeled as suffering from FM. Furthermore, the development of better and more objective diagnostic tools holds the promise to reduce the "transparent" nature of FM and to reduce the numbers of "fibro-skeptics". While it is hard to anticipate whether FM will remain strictly within the realm of rheumatology, what really matters is that FM continues to be treated and studied by those most interested in the subject, which may evolve into a more heterogeneous and multidisciplinary group. On the therapeutic side, huge interest regarding the role of cannabinoids in the management of chronic pain is likely to lead to a radically more extensive understanding of the cannabinoid system and its therapeutic potential. Other, non-pharmacological treatment modalities such as neurofeedback, hyperbaric oxygen, and magnetic stimulation are likely to gain a place in the therapeutic armamentarium. Thus, the story of FM will continue to evolve.
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