What is the link between trauma and fibromyalgia? by Dr IVAN RAMOS-GALVEZ, consultant in pain medicine
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FIBROMYALGIA (FM) is a chronic condition characterised by widespread deep musculoskeletal pain accompanied by various other non-specific symptoms, including chronic fatigue, sleep and mood disturbances and cognitive problems. The condition is relatively common, occurring in around 2-8% of the adult population, and is much more common in women than in men. For years the existence of FM was a controversial topic, but nowadays it is generally accepted as a real entity. However, there is still no available test to confirm diagnosis and the reporting of symptoms is entirely subjective. It has been suggested that in up to one third of cases FM may be triggered by previous traumatic events in the patient’s life, with the other two thirds occurring spontaneously. Physical trauma, often in the form of an accident at work or a traffic collision, is commonly cited as a precipitating event for FM. However, it is difficult to prove causation, particularly where an incident has not caused any visible injury. Despite that, increased rates of FM following accidents have been widely reported. Studies in the UK, US and Israel have reported incidence rates of between 1% and 22% for FM or diffuse pain for individuals involved in car and train accidents. Those rates appear much higher than would be expected in the general population, particularly in individuals in whom the original injury occurred in the neck. Furthermore, in one study an ‘at-risk’ group could be identified on the basis of poorer health and psychological variables. However, a study conducted in Lithuania, where disablement is both less common and less well compensated, found no cases of chronic neck pain following a motor vehicle accident. Workplace injury is also often cited as a causal factor in FM. Prospective studies of new workers have reported that, 12 months after starting the job, rates of chronic widespread pain were as high as 15%. The majority of cases appear to be due to a single injury, with the lower back and shoulder being the most commonly cited areas of damage. However, generalised activities such as repetitive movements, lifting, pushing or pulling heavy weights, kneeling or squatting and working with the hands at or above shoulder height have also been claimed as triggering factors. Psychosocial factors, such as monotonous work and low social support, appear to increase the risk even further.
Psychological trauma and FM
As well as physical trauma, many studies have reported an increased prevalence of psychological trauma in FM patients. Adversity in early life appears to be particularly important. Factors such as being taken into care, the death of a parent, family financial hardship, emotional neglect and behavioural problems have all been linked to chronic widespread pain later in life, and those associations appear to be more marked in patients who are not concurrently suffering from depression. A clear gradient of increasing loss of function in participants with higher trauma scores, which again was seen more clearly in non-depressed individuals, has also been reported. Childhood abuse nearly doubles the risk of developing a chronic pain condition, including FM, in adulthood. However, a lifelong history of sexual abuse does not show an association with FM, suggesting that the timing of the trauma may be critical. When taken as a whole, there does appear to be evidence of a link between trauma and the development of FM. A review of 51 studies found that the majority reported a significant association between physical or emotional trauma and the onset of chronic widespread pain or FM. The evidence appeared to be strongest for psychological trauma and FM, where the link was widely demonstrated. However,
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many of the studies on which this review was based provided data which was of low-quality, when assessed by GRADE criteria. One major problem with most of the evidence regarding trauma and FM is that it comes from retrospective studies, which are reliant on the participants’ recollection of traumatic events. Patients who are suffering from a disease with no obvious cause may look for past events in an attempt to explain their condition. However, research shows that adult recall of adverse childhood experiences actually tends to underreport such events. That would tend to dilute any associations seen between trauma and FM. Some adults do not report childhood trauma because they feel they have ‘moved on’ and no longer identify as a trauma survivor. Others will simply not remember events that happened in very early childhood. Individuals who continue to report trauma may have been more negatively affected by the event and thus more likely to experience greater pain-related disability in later life. Another issue with retrospective studies, particularly those of a cross-sectional design, is that the temporal relationship between trauma and FM cannot always be established. A clear and logical time sequence is critical in trying to prove causality. Finally, physical trauma, such as a serious accident, is almost always accompanied by psychological sequelae and it is difficult to separate out the role that each plays in the causation of FM. The mechanisms by which trauma leads to FM are not entirely clear. It has been suggested that certain aspects of physical work may result in centralised pain sensitivity. Traumatic experiences in early life may predispose to FM by excessively activating stress responses during a critical period of development, thus altering normal development and reactions to stress and painful stimuli through hyperalgesic priming. As the resulting pain is a stressor, it may lead to a positive feedback loop, which serves to increase anxiety levels and further impact on stress regulation. Alteration of the stress response appears to be mediated via the hypothalamic-pituitary-adrenal axis, although the precise way that happens is not yet known. Trauma increases the responsiveness of the central nervous system due to decreased functional connectivity in the descending pain-modulating system and heightened sensory responses. Furthermore, childhood abuse has been linked to a disruption of normal diurnal cortisol levels – a hormone associated with stress – and that effect has also been observed in FM patients. The observation that experiences in early life can lead to FM many decades later suggests that the neuroplastic changes associated with stress are part of a chronic process that develops slowly. It is also likely that the effects of traumatic events are mediated by the individual’s genetic predisposition and psychological status.
Treatments for FM
FM is a difficult condition to treat: pharmacological treatments are not effective for many patients. As a result, non-pharmacological interventions such as cognitive behavioural therapy (CBT) are often recommended, but frequently only lead to modest improvements in the patient’s condition. Recently, research has examined the concept of customising treatment on the basis of psychosocial needs to increase its efficacy. One approach, called emotional awareness and expression therapy (EAET), combines techniques from several other psychologically-based therapies. That approach tries to reduce pain and other symptoms by framing FM as a central nervous system-based process that is strongly
