Do motor vehicle accidents cause fibromyalgia?
Shawn Uraine, M.D., Peter Lapen, D.O.
Fibromyalgia (FM) is a rheumatological condition impacting the lives of about 2-12% of the population in various nations, depending on the diagnostic criteria used. This illness is extremely costly to societies in terms of both human suffering, monetarily and lost productivity. This condition is extremely challenging to both patients and providers; magnified by the complexity of medicolegal entanglement. Over the years the diagnostic criteria has evolved. Also, recent literature shows growing evidence of association of mental illness as a trigger or pre-disposing factor to the development of FM, in addition to genetic factors. This contrasts with some earlier research implying previous injuries, in particular motor vehicle accidents, precipitate the development of FM.
Fibromyalgia is a condition leading to a growing amount of medicolegal disability claims, loss of work, and non-monetarily quantifiable human suffering. This literature review encompasses a review of publications that update the current diagnostic criteria, and increasing evidence the burden of the disease is modifiable. Furthermore, this review will highlight evidence showing while genetic and environmental factors contribute to the disease process, there is significant evidence the summation of disability is independent of physical injury, and is more closely correlated to biopsychosocial factors, which in some cases, are also modifiable. The aim of this review is to focus provider attention to the importance of early intervention and the importance of further research in occupational and vocational rehabilitation to reduce the burden of disease.
Fibromyalgia (FM) is considered to be the second most common “rheumatic” disease after osteoarthritis. The first diagnostic criteria was established in 1990 by the American College of Rheumatology (ACR) and required tenderness in 11 of 18 of the tender points, and had a sensitivity of 88% and a specificity of 81%(3). In 2010 The ACR changed their criteria in 2010 to focus on symptoms rather than tender points and will likely identify more male patients with fibromyalgia, because females are more likely to have tenderness upon palpation(3). After further refinements, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks (ACTTION) public-private partnership with the US Food and Drug Administration (FDA) and the American Pain Society (APS) initiated the ACTTION-APS Pain Taxonomy (AAPT) criteria for Fibromyalgia with an international FM working group, released in June 2019 listed below.
Depending on diagnostic criteria used, the prevalence of FM ranges from 2-8%(1), with variance of prevalence from 0.5% to 12% of the population and can occur at any age, depending on the method of ascertainment (2) The incidence rises at 50-59 years of age and drops off after 80+ years of age(2). Females outnumber males 3:1 in studies that do not use tender points as a criterion (2). FM also occurs in relatively equal frequency in different countries, cultures and ethnic groups, yet there is increased frequency in “industrialized” nations. FM patients averaged 1 outpatient visit per month with a mean yearly per patient cost of 7 years totaling $2,2474 in 1996 dollars. In Quebec, the mean direct annual cost of FM was estimated to be $3,804 and 6 days were lost due to pain over 3 months. One-third of FM patients in Canada received disability payments according to a recent study (2). European researchers have estimated the economic and financial burden of FM in Europe in 2001 to be an annual cost per person of $8,690, 88.5% attributable to loss of productivity and disability. Employment rates there vary, ranging from 34-77%(7). The indirect costs are high due to lost work productivity and the highest direct cost is in the US compared to France and Germany (2). In a large US health care database study with >30,000 FM patients, healthcare costs were 3 times higher than controls (2). Individuals who go on to develop FM nearly always have a history of multiple painful areas of their body throughout their life; presenting a “pain prone phenotype”. Beginning in childhood and adolescence, FM patients are likely to have developed headaches, dysmenorrhea, temporal mandibular joint disorder, chronic fatigue, irritable bowel syndrome, interstitial cystitis, endometriosis and other regional pain syndromes (1). Furthering evidence of a strong genetic component, 1stdegree relatives are 8 times more likely to have chronic pain than controls. Twin studies have also suggested developing FM or other pain related conditions like IBS or headache is 50% genetic and 50% environmental (1).
Candidate gene studies showed that genetic findings such as serotonin 5-HT2A receptor polymorphism T/T phenotype, serotonin transporter, dopamine 4 receptor, and COMT polymorphisms all were noted in higher frequency in patients with FM than controls. Some subsequent studies confirmed some of these associations, but others did not (2). Linkage studies confirmed the strong genetic contribution to FM to the chromosome 17p11.2q11.2 region (2). The large candidate study identified significant differences in allele frequencies between FM patients and controls for 3 genes GABRB3, TAAR1, and GBP1. These 3 genes and 7 others were examined in a second independent cohort of FM patients and evidence of associated in the replication cohort was observed with TAAR1, RGS4, CNR1 and GRIA4. However, because genetic studies have not yet identified strong reproducible polymorphisms or haplotypes associated with FM and there is in fact, clear evidence of environmental stressors playing a large role in pathogensis, other groups have postulated that epigenetic findings might be important in FM (2).
Some evidence has shown anatomic abnormality and energy deficit in skeletal muscle has been implicated as a cause, but has been a subject to debate due to the consideration that these abnormal findings could be due to due to the deconditioning associated with the disease. Nonetheless, it has been suggested patients with FM have low chemical energy because of lower than normal adenosine triphosphate levels in red blood cells (4). Neuroendocrine dysfunctions are also found in FM. Functional abnormalities of the hypothalamic-pituitary-adrenal axis, sympathoadrenal gland, and hypothalamic-pituitary growth hormone axis have been discovered. These abnormalities explain the dizziness, lightheadedness FM patients experience likely due to orthostatic hypotension. Furthermore, measures of heart rate variability show persistently high sympathetic activity at night manifesting in insomnia, morning stiffness and daytime fatigue and FM patients (4). That in itself, is another terrible cycle that further deteriorates functionality and quality of life in the population suffering with FM.
The environmental factors that are likely to trigger development of FM include illness or certain types of infection like Epstein-Barr Virus, Lyme Disease, Q-Fever, and viral hepatitis. History of deployment to war, but not specifically physical injury in war, was commented by Benzon et al as a trigger to later development of FM (1). Anecdotally, the author of this paper can personally recall a high prevalence of widespread myalgias, depression like symptoms and suspicious fractures and co-morbid vitamin D deficiency in troops returning from deployment to the middle east in 2012. Without formal study, this a clear association could not be made. Psychological stress is repeatedly found to correlate closely to presence of FM. In 2004, Thieme et al performed a cohort study in 2004 studying Psychiatric comorbidities in 115 female FM patients recruited from Rheumatology clinics and hospitals in Germany. After statistical analysis, they found their patients presented with vastly higher prevalence of psychiatric disorders compared to the general population. Axis I disorders were found in 77.3% of the sample. 32.2% of the FMS patients reported anxiety, 34.8% presented with mood disorders, and 1.75% met criteria for substance related disorders compared to 10% and 9% that have mood and anxiety disorders in the general population, respectively (5). Another strong study from Germany was published in PAIN in 2013, presenting a clear link between psychiatric conditions and the syndrome of FM and its prognosis. 395 patients were studied and 45% of patients with FMS had PTSD, 52% had other terrible life events, 15% witnessed terrible life event in another person, and 10% were sexually abused before age 14 years. 66% of patients traumatic life events and PTSD symptoms preceded the onset of chronic widespread pain (CWP), compared to 30% of patients experiencing PTSD or traumatic life experiences after onset of CWP.
4% of patients experienced PTSD, traumatic life experience and CWP in the same year. PTSD was also seen to have a negative impact on clinical outcomes. PMS patients with PTSD reported more pain sites, somatic and psychological distress and disability and were more frequently without a job than FMS patients without PTSD(5). These studies offer some convincing evidence traumatic experiences as well mental illness are factors that can facilitate the development of FM. This correlation is interesting considering both FM and mental illness are both a product of a combination of “nurture” and “nature”.
Other psychosocial stressors have been elucidated to be triggers for FM as well. These include occupational stressors. This is particularly of interest considering the entanglement of disability and workman’s compensation claims. Laroche et al studied the link between occupational factors and disability manifested at sick leave days. During a 5 month inclusion period, 955 women were surveyed. This study found women with FM taking sick leave were more likely to report feeling aggravated by work, and, women with FM who took sick leave were significantly more likely than those with FM that did not. Job characteristics of those taking time off from work included repetitive gestures, noisy work places, and working with screens. Sedentary jobs, jobs with carrying heavy loads, thermal nuisances and use of vibrating tools were found equally prevalent in those taking sick leave and not taking sick leave (7).
Interestingly, there was no association with sick leave and demographics or clinical characteristics of FM. Rather, there was an association between sick leave and commute time, difficulties at work, problems with career progression, sedentary position with repetitive gestures and a lack of recognition of FM by colleagues or bosses (7). This highlights the importance of help from occupational physicians on staff and their interface with the patient’s employer as well as vocational counseling to minimize disability vis-à-vis sick leave. Another take home point from this study was that FM by itself does not directly cause sick leave, thereby warranting disability.
Some environmental factors have historically been implicated in the development of FM but have later been refuted. In particular, whiplash injuries from motor vehicle accidents (MVA) have been believed to trigger fibromyalgia (1). Some research has sought to associate Apo E4 genotypes in FM patients with FM triggered by whiplash injuries from MVAs, but, admittedly, the subjects in the study were gathered in a retrospective study using an analysis of EMR, which, due to record inconsistencies did not confirm ACR criteria for diagnosis of the condition of FM, questioning the strength of the link between MVA and FM. There is however, quite good evidence that whiplash injuries do not cause FM. Tishler et al, in Israel, conducted a prospective study on 153 patients recruited from emergency departments after sustaining whiplash injuries. After a mean time of 14.5 months, only one out of 153 patients developed FM, about 6.5%. This aligns closely with the natural incidence of this syndrome in general population previously described in this paper. This was in great contrast to Buskila et al, who previously claimed 21.6% of workplace neck injuries developed FM shortly after initial injury. The Tishler publication also pointed out the previous study by Buskila and colleagues was biased due to the place of recruitment. The patients in their study were chosen from an occupational injury clinic and these patients were already claiming their insurance/social security and therefore, were not representative of the whole injured group (9). Not resting on their laurels, Tishler and colleagues conducted a 3-year follow up to their initial work.
Once again, Tishler and colleagues found no statistically significant increase in FM in the study group of whiplash injuries compared to control group (10).
While FM can be a life altering condition, it is important for providers to convey to patients that their diagnosis is not a condemnation. The condition is modifiable; and in some cases, patients can achieve remission. As previously discussed, a common symptom of FM is difficulty controlling emotions, fatigue, pain, poor sleep, migraines, paresthesia, anxiety and stress due to autonomic dysfunction from neuroendocrine dysregulation. A systematic review by Andrade et al in 2019 showed Resistance training was associated with reduced symptoms of anxiety, depression and increased muscle strength in patients with FM. On the other hand, Moderate to high intensity aerobic exercise performed at least twice per week increased heart variability (11). Moreover, lower physical activity worsens the impact of the illness of FM (12). Furthermore, in a prospective Australian primary care study, 47% no longer met criteria for FM diagnosis sometime after diagnosis, and 24% achieved remission. In another study, one-third of FM patients in Canada experienced good outcomes.
While it is clear the symptoms, and disability of FM can be modifiable, and intervention at any time is likely to beneficial in some capacity, the question can be raised, “Is there a best time?”. An Australian study studied the impact on the ability of Australians with FM to work. Members of the Fibromyalgia Support Network of Western Australia were invited to participate in an anonymous online survey with particular interest in their ability to work with relationship to their symptom onset, time of diagnosis and at time of survey.
The study showed as time from onset of symptoms progressed, so did the proportion of participants ceasing to work due to FM symptoms. Also concerning is the impact on the work force. From time to diagnosis to time of survey, the full-time work makes a sharp downward turn, while casual and part time employment remains relatively flat. This trend in the difference in ability to work after diagnosis adds credibility to the claim Laroche et al commented upon, that occupational stressors in the workplace can be “dosing dependent”. These findings indicate there may be window of opportunity for early intervention in an effort to salvage work ability (13).
FM is challenging condition for patient and provider and takes a great toll on both the individual and society. The exact mechanisms of the condition are still not well known. There is strong evidence that there are both inherited, non-modifiable causes, but also modifiable, environmental causes. There is convincing evidence that the condition should not be tied to any particular physical injury, unless it was so severe to cause great psychological stress. Psychological stressors with a high association to FM are PTSD, anxiety and mood disorders. This association not only points out role striking role of mental illness and psychological trauma in the development of FM, but also, the importance of providers caring for FM patients to work closely with a mental health service. Occupational health departments should also take a proactive role in maintaining good industrial hygiene in order to maintain a healthy work force, minimizing the individual and societal costs of FM; both human and monetary. And finally, recent literature shows that the symptoms and total burden of FM may be improved with early intervention. This intervention must include not the provider alone, but a multidisciplinary care team in which the role of vocational rehabilitation cannot be overlooked for optimal convalescence and minimization of disability, as eluded to by Laroche et al, and Guymer et al.
1) Benzon et al: Essentials of Pain Medicine. Fourth Edition. 213-221. 2018
2) Arnold et al: AAPT Diagnostic Criteria for Fibromyalgia. The Journal of Pain, Vol 20, No 6 (June), 2019: pp611-628.
3) Kodner, C: Common Questions About the Diagnosis and Management of Fibromyalgia. Am Fam Physician. 2015;91(7):472-478.
4) Braddom, R. Physical Medicine and Rehabilitation. Fourth Edition. 995-997.
5) Thieme et al: Comorbid Depression and Anxiety in Fibromyalgia Syndrome: Relationship to Somatic and Psychosocial Variables. Psychosomatic Medicine. 2004;66: 837-844
6) Haeuser et al: Posttraumatic Stress Disorder in Fibromyalgia Syndrome: Prevalence, Temporal Relationship Between Posttraumatic Stress and Fibromyalgia Symptoms, and Impact on Clinical Outcome. PAIN. 154 (2013) 1216-1223.
7) Laroche et al: Fibromyalgia in the workplace: Risk Factors For Sick Leave are Related to Professional Context Rather Than Fibromyalgia Characteristics-A French National Survey of 955 Patients. BMC Rheumatology. (2019) 3:44
8) Reeser et al: Apolipoprotein E4 Genotype Increases the Risk of Being Diagnosed with Posttraumatic Fibromyalgia. PM&R. Vol 3. 193-197. March 2011.
9) Tishler et al: Neck Injury and Fibromyalgia—Are They Really Associated? The Journal of Rheumatology. 2006; 33; 1183-1185.
10) Tishler M, Levy O, Amit-Vazina M: Can Fibromyalgia be Associated With Whiplash Injury? A 3-Year Follow-up Study. Rheumatology International. (2011) 31:1209-1213.
11) Andrade et al: Modulation of Autonomic Function by Physical Exercise in Patients With Fibromyalgia Syndrome: A systematic Review. PM&R. 11(2019) 1121-1131.
12) Vincent et al: Decreased Physical Activity Attributable to Higher Body Mass Index Influences Fibromyalgia Symptoms. PM&R. 6 (2014) 802-807
13) Guymer et al: Fibromyalgia Onset has a High Impact on Work Ability in Australians. Royal Australasian College of Physcians. (2016) 1069-1074.