Gender as a Risk Factor for Functional Movement Disorders: The Role of Sexual Abuse

Abstract

Background Background: The prevalence of functional movement disorders is 2 to 3 times higher in women than in men. Trauma and adverse life events are important risk factors for developing functional movement disorders. On a population level, rates of sexual abuse against women are higher when compared with the rates against men. Objectives Objectives: To determine gender differences in rates of sexual abuse in functional movement disorders compared with other neurologic disorders and evaluate if the gender prevalence is influenced by higher rates of sexual abuse against women. Methods Methods: We performed a case-control series including 199 patients with functional movement disorders (149 women) and 95 controls (60 women). We employed chi-squared test to assess gender and sexual abuse associations and Bayes formula to condition on sexual abuse. Results Results: Our analysis showed an association between sexual abuse and functional movement disorders in women (odds ratio, 4.821; 95% confidence interval, 2.089-12.070; P < 0.0001), but not men. Bayesian analysis found the functional movement disorder prevalence ratio between women and men conditional on sexual abuse to be 4.87 times the unconditioned ratio. ConclusionsConclusions: There is a statistically significant association between sexual abuse and functional movement disorders in women and a greater likelihood that women who are sexually abused will develop functional movement disorders than men who are sexually abused. Our findings suggest that the increased prevalence of functional movement disorders in women is associated, at least in part, with sexual abuse and its sequelae; however, further research is needed to explore the role of other traumatic and nontraumatic factors.Functional movement disorders (FMD) are commonly seen in neurologic practice and are characterized by abnormal control over movements, often presenting with tremor, dystonia, and gait disorders and associated nonmotor complaints with evidence of symptom incompatibility with recognized neurologic diseases. 1 The prevalence of functional movement disorders is 2 to 3 times higher in women than in men. 2 Since the advent of modern psychiatry, a correlation between the experience of emotional trauma and psychogenic symptoms has been postulated. 3 This relationship led to the original terminology of conversion disorder-the belief that stressful mood states were converted into sensorimotor neurologic processes. 1,4 Despite significant criticisms and limitations of this theory, the role of stress and trauma remain important risk factors for developing functional neurological disorders. 5 Given the higher rates of sexual abuse (SA) in women when compared with men, 6 we hypothesized that the previously reported gender association of functional movement disorders is influenced by higher rates of SA against women. MethodsTo test our hypothesis, we performed a retrospective analysis of deidentified data from 2 academic referral sites (National Institutes of Health and the University of Louisville),...

Cranial Functional Movement Disorders: A Case Series with Literature Review

“…Since the advent of modern psychiatry, a correlation between the experience of emotional trauma and psychogenic symptoms has been postulated [35]. Kletenik et al pointed out that trauma and adverse life events are important risk factors for developing FMDs and they have also reported that the higher prevalence of FMDs in women is likely related to both higher rates of sexual abuse against women and the impact of sexual abuse in women [36]. But in our Indian society, there seems to be a significant impact of culture, ethnicities, and other psychosocial variations on the precipitating factors.…”

Reply to Gender Differences in Functional Movement Disorders: Sociocultural or Biological?

“…Moreover, a convergence in selected pathophysiological aspects between organic and functional dystonia has been shown in some studies. 2 Finally, although the term "gender differences" is often used in medical literature, including in our 1 and other articles, 4 we acknowledge that the term "sex differences" may be more appropriate. The latter term "refers to individuals as either male or female on the basis of reproductive organs and functions assigned by the X and Y chromosomes, whereas gender also encompasses one's self and social identity, which is rooted in biology but also shaped by environmental factors."…”

“…In a case-control series, reported in the same issue as our article, 1 which included 199 patients with FMDs, of whom 149 were women, and 95 controls (60 women), a significant association was found between sexual abuse (a form of psychological trauma) and FMD in women (odds ratio: 4.821; P < 0.0001), but not men. 4 The researchers concluded that the increased frequency of FMDs in women "is associated, at least in part, with sexual abuse and its sequelae; however, further research is needed to explore the role of other traumatic and non-traumatic factors." Although sexual abuse may contribute to the observed sex-related differences, other factors, including social, cultural, psychological, and biological, may be important in FMDs as well as in other movement disorders.…”

Gender, Abuse, and Functional Movement Disorders: From His‐story to the Future

“…Kletenik and colleagues specifically considered the issue of sexual abuse. They used a standardized instrument to assess the presence of trauma (The Trauma Life Events questionnaire) in a cohort of 199 patients diagnosed with FMD compared to 95 neurological control patients without FMD.…”

“…For example, testosterone affects approach‐avoidance responses to threat . As Klerenik and colleagues point out, there is evidence that sexual abuse can affect sense of embodiment and self‐agency. There has been increasing interest in the relevance of abnormalities in interoception in FND, arguably the network that it is at the heart of embodiment and self‐agency, and it is possible that this could be a route by which sexual abuse predisposes people to development of FMD.…”