Stress, childhood trauma, and cognitive functions in functional neurologic disorders

Peripheral and Central Nervous System Biomarkers of Inflammation in Functional Seizures: Assessment with Magnetic Resonance Spectroscopy

Purpose

Inflammation may link trauma to clinical symptoms in functional seizures (FS). We compared brain temperature and metabolites in FS, psychiatric (PCs) and healthy controls (HCs) and quantified their associations with serum biomarkers of inflammation and clinical symptoms.

Patients and Methods

Brain temperature and metabolites were measured with whole-brain magnetic resonance spectroscopic imaging (MRSI) and compared between groups in regions of interest and the whole brain. Relationships with inflammatory biomarkers and symptoms were assessed with Pearson correlations.

Results

Brain temperature was higher in FS than HCs in the orbitofrontal cortex (OFC) and anterior cingulate gyrus (ACG) and lower in the occipital cortex and frontal lobe. PCs showed lower temperatures than HCs in the frontal lobe including precentral gyrus and in the cerebellum. Myo-inositol (MINO) was higher in FS than HCs in the precentral gyrus, posterior temporal gyrus, ACG and OFC, and choline (CHO) was higher in the occipital lobe. CHO was higher in PCs than HCs in the ACG and OFC, and N-acetylaspartate (NAA) was higher in the ACG. There were no significant correlations with the serum inflammatory biomarkers. In FS, brain temperature correlated with depression, quality of life, psychological symptoms, and disability, CHO correlated with disability, and MINO correlated with hostility, disability, and quality of life.

Conclusion

Some of the previously identified neuroimaging abnormalities in FS may be related to comorbid psychiatric symptoms, while others, such as abnormalities in sensorimotor cortex, occipital regions, and the temporo-parietal junction may be specific to FS. Overlapping MINO and temperature increases in the ACG and OFC in FS suggest neuroinflammation.

Case study of invalid to valid shift in cognitive performance following successful treatment of psychogenic nonepileptic seizure events

Patients with psychogenic nonepileptic seizure (PNES) who fail performance validity testing (PVT) may appear to produce non-valid cognitive profiles. Consequently, they may not get referred to treatment and events persist, with worsening disability and high resource utilization. As a result, we report pre- and post-treatment neuropsychological evaluation findings in a 59-year-old woman with a confirmed diagnosis of PNES established using video-EEG monitoring. At pre-treatment baseline neuropsychological evaluation, PNES events occurred weekly to daily. Performance was impaired across PVTs and across multiple cognitive domains. After behavioral intervention specific to PNES, these events substantially reduced in frequency to rare stress-induced flares. Post-treatment neuropsychological evaluation revealed marked improvement of most cognitive and behavioral scores from baseline, and valid PVT scores. We review predisposing, precipitating, and perpetuating factors for PNES and cognitive impairment in this case and discuss the patient's outcome from treatment. Effectively managing PNES events and dissociative tendencies while reducing unnecessary pharmacological interventions appears to have allowed this patient to function closer to her optimal state. This case illustrates the complexity of Functional Neurologic Disorder (FND) clinical presentation and challenges the assumption that suboptimal neuropsychological performance predicts poor treatment engagement and outcome. We showcase the reversibility of PNES and cognitive manifestations of FND using targeted psychotherapeutic interventions, which resulted in reduced disability and associated healthcare costs, as well as re-engagement in life.

Clinical impact and misdiagnosis of functional ophthalmological symptoms: a case report

BACKGROUND

There is a high prevalence of somatoform disorders and medically unexplained symptoms. When it comes to deciding whether a patient is able to work, it is essential to differentiate a somatoform disorder from a factitious disorder. The case presented demonstrates the impact on disability benefits and the subsequent psychosocial repercussions of misdiagnosing between a factitious disorder and a somatoform disorder.

CASE PRESENTATION

A 42-year-old Caucasian woman worked as a 100% fiduciary accountant until the age of 32 when she was placed on medical leave due to persistent trigeminal neuralgia. Afterward, she developed total blindness, not explained by a physiological process, accompanied by distress in a crucial emotional context. We evaluated the patient for a revision of a disability income after a diagnosis of factitious disorder with severe consequences such as disability income suspension and family conflict. Our psychiatric examination concluded the diagnoses of pain disorders related to psychological factors and a dissociative neurological symptom disorder with visual disturbance.

CONCLUSIONS

Blindness not explained by a physiological process may accompany trauma and psychological distress. Differentiating this pathology from factitious disorder or simulation is essential from an insurance medicine point of view, but also for its treatment.

The neurobiology of functional neurological disorders characterised by impaired awareness

We review the neurobiology of Functional Neurological Disorders (FND), i.e., neurological disorders not explained by currently identifiable histopathological processes, in order to focus on those characterised by impaired awareness (functionally impaired awareness disorders, FIAD), and especially, on the paradigmatic case of Resignation Syndrome (RS). We thus provide an improved more integrated theory of FIAD, able to guide both research priorities and the diagnostic formulation of FIAD. We systematically address the diverse spectrum of clinical presentations of FND with impaired awareness, and offer a new framework for understanding FIAD. We find that unraveling the historical development of neurobiological theory of FIAD is of paramount importance for its current understanding. Then, we integrate contemporary clinical material in order to contextualise the neurobiology of FIAD within social, cultural, and psychological perspectives. We thus review neuro-computational insights in FND in general, to arrive at a more coherent account of FIAD. FIAD may be based on maladaptive predictive coding, shaped by stress, attention, uncertainty, and, ultimately, neurally encoded beliefs and their updates. We also critically appraise arguments in support of and against such Bayesian models. Finally, we discuss implications of our theoretical account and provide pointers towards an improved clinical diagnostic formulation of FIAD. We suggest directions for future research towards a more unified theory on which future interventions and management strategies could be based, as effective treatments and clinical trial evidence remain limited.

Functional ear symptoms referred to an otology clinic: incidence, co-morbidity, aetiological factors and a new experience-driven clinical model

OBJECTIVE

This study aimed to review the incidence and co-morbidity of functional ear symptoms in new referrals to an adult otology clinic and present a clinical model based on neuroscientific concepts.

METHOD

This was a retrospective review of 1000 consecutive new referrals to an adult otology clinic.

RESULTS

Functional disorder was the primary diagnosis in 346 patients (34.6 per cent). Functional ear symptoms included tinnitus (69.7 per cent), imbalance (23.7 per cent), otalgia (22.8 per cent) and aural fullness (19.1 per cent), with more than one symptom occurring in 25.1 per cent of patients. Co-morbidities included sensorineural hearing loss (39 per cent), emotional stress (30 per cent) and chronic illness (22 per cent).

CONCLUSION

Functional disorders commonly present to the otology clinic, often in the presence of emotional stress or chronic illness. They occur because of adaptation of brain circuitry to experience, including adverse events, chronic illness and fear learning. This study presented an experience-driven clinical model based on these concepts. An understanding of these principles will significantly aid otolaryngologists who encounter patients with functional ear symptoms.

Subjective versus objective measures of distress, arousal and symptom burden in patients with functional seizures and other functional neurological symptom disorder presentations: A systematic review

Symptoms and functioning can be measured subjectively using self-report measures or objectively, based on physiological changes. This raises the question whether subjective and objective measures are closely correlated and - if not - whether one is more accurate or meaningful than the other, especially in patients with Functional Seizures (FS) or other Functional Neurological Symptom Disorders (FND), where subjective and objective observations may be thought particularly likely to deviate. This systematic review explores these questions focussing on measures of distress, arousal and symptom burden. Eighteen studies (12 FS, 6 other FND) capturing 396 FND patients were included. Eleven reported no correlation between subjective and objective measures. Only four studies reported significant correlations (r's = -0.74-0.59, p's < 0.05). The small number of studies and diverse methodologies do not provide conclusive answers to the questions posed. Given that subjective and objective measures capture different aspects of current state or function, a combination of measurement approaches is likely to provide optimal information about patients' health state. In view of the attentional and perceptual alterations implicated in FND, the difference between objective and subjective measures may represent an interesting observation in its own right.

The synergetic effect of childhood trauma and recent stressful events in psychosis: associated neurocognitive dysfunction

BACKGROUND

A higher incidence of childhood trauma (CT) has been reported in first episode of psychosis (FEP). There is, however, a lack of knowledge about the synergetic effect between CT and recent stressful events (RSE).

METHODS

Information on specific types of CT (under 17 years) and RSE (within the past 3 years) was available for 290 FEP patients and 52 healthy controls (HC). Cognitive function at baseline was assessed through a comprehensive neuropsychological test battery.

RESULTS

While 45.2% of FEP patients and 25% of HC reported at least one CT event, 62.7% of FEP and 21.2% of HC reported an RSE. Meanwhile, 36.2% of FEP patients and 9.6% of HC encountered both childhood and recent stressful events. The patients that just reported CT showed normality in all but the verbal memory cognitive domain; those with additive CT and RSE presented worse general cognitive function, specifically on working memory, processing speed, and executive function. RSE and general cognitive dysfunction were significant determinants of psychosis onset.

CONCLUSIONS

These results support a synergetic influence of trauma and stressful events on brain function and allow a better understanding of mediators for psychotic disorders useful in the design of specific strategies based on stress-targeted therapies.

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

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

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

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

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.

Conclusions

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.

The Role of Attachment Trauma and Disintegrative Pathogenic Processes in the Traumatic-Dissociative Dimension

Epidemiological, clinical, and neurobiological studies of the last 30 years suggest that traumatic attachments during the early years of life are associated to specific psychopathological vulnerabilities based on dissociative pathogenic processes. It has been observed that the dissociative pathogenic processes caused by these traumatic attachments either may contribute to the genesis of well-defined mental disorders (e.g., dissociative disorders) or may variably occur in many other diagnostic categories, complicating their clinical pictures and worsening their prognosis. For this reason, we proposed to define the dimension of psychopathological outcomes linked to traumatic attachments and dissociative pathogenic processes as the "traumatic-dissociative" dimension (TDD). The clinical complexity of the TDD requires specific training to enable mental health professionals to recognize the signs of traumatic developments and to implement specific treatment strategies. The present article aims to review some crucial points about the clinical meaning and treatment strategies of the TDD, the dissociative pathogenic processes characterizing the TDD, as well as of the role of attachment trauma in the TDD. We also focused on the clinical and theoretical evidence suggesting that dissociation and dis-integration may be considered two different processes but highly correlated. The usefulness of clinical reasoning in terms of psychopathological dimensions, instead of distinct diagnostic categories, as well as several therapeutic implications of these issues was finally discussed.

Abnormal postural behavior in patients with functional movement disorders during exposure to stress

BACKGROUND

Patients affected by functional (psychogenic) movement disorders (FMD) have abnormal processing of stress responses. However, little is known about the influence of this abnormal stress processing on automatic motor defense behavior, such as freeze response. Our aim was thus to investigate stress-induced postural motor responses in FMD.

METHODS

Nine FMD patients and thirteen healthy controls were engaged in the Trier Social Stress Test, while we measured the movement of their body by means of accelerometers and gyroscopes attached to the thorax. Standard deviation of thorax acceleration, reflecting the variability of movement amplitude (body sway), was compared across groups over time in a 2 × 2 ANOVA design. Higuchi's fractal dimension (HFD), reflecting the complexity of movement pattern over time, was also analyzed. Salivary cortisol and α-amylase samples were collected before and after the experiment, as stress biomarkers. Pearson's correlation coefficients were calculated between these biomarkers and movement parameters.

RESULTS

A significant interaction effect was found, showing that healthy controls reduced their thorax sway over time during exposure to stress (from 0.027 ± 0.010 m/s² to 0.023 ± 0.008 m/s², effect size of Cohen's d = 0.95), whereas patients with FMD did not. This change in body sway in controls over time negatively correlated with salivary cortisol values (ρ = -0.67, p = 0.012). A significant group effect revealed that FMD patients had an overall larger body sway (0.038 ± 0.013 m/s²) compared to controls (0.025 ± 0.009 m/s² - effect size of Cohen's d = 1.29) and a lower HFD (1.602 ± 0.071) than controls (1.710 ± 0.078 - Cohen's d = 1.43).

CONCLUSIONS

Patients with FMD failed to show a reduction of body sway over time, i.e., freeze response observed in the controls, thus suggesting an impairment in the automatic defense behavior. Moreover, our analysis found a lower complexity of movement (HFD) in FMD, which deserves future research in order to verify whether this could represent a characteristic trait of the disorder.

Pathogenesis and pathophysiology of functional (psychogenic) movement disorders

Functional movement disorders (FMDs), known over time as "hysteria", "dissociative", "conversion", "somatoform", "non-organic" and "psychogenic" disorders, are characterized by having a voluntary quality, being modifiable by attention and distraction but perceived by the patient as involuntary. Although a high prevalence of depression and anxiety is observed in these patients, a definitive role of psychiatric disorders in FMDs has not been proven, and many patients do not endorse such manifestations. Stressful events, social influences and minor trauma may precede the onset of FMDs, but their pathogenic mechanisms are unclear. Patients with FMDs have several abnormalities in their neurobiology including strengthened connectivity between the limbic and motor networks. Additionally, there is altered top-down regulation of motor activities and increased activation of areas implicated in self-awareness, self-monitoring, and active motor inhibition such as the cingulate and insular cortex. Decreased activation of the supplementary motor area (SMA) and pre-SMA, implicated in motor control and preparation, is another finding. The sense of agency defined as the feeling of controlling external events through one's own action also seems to be impaired in individuals with FMDs. Correlating with this is a loss of intentional binding, a subjective time compression between intentional action and its sensory consequences. Organic and functional dystonia may be difficult to differentiate since they share diverse neurophysiological features including decreased cortical inhibition, and similar local field potentials in the globus pallidus and thalamus; although increased cortical plasticity is observed only in patients with organic dystonia. Advances in the pathogenesis and pathophysiology of FMDs may be helpful to understand the nature of these disorders and plan further treatment strategies.

Positive clinical signs in neurological diseases - An observational study

Many patients with organic neurological disease have symptoms and signs that are unexplained by their disease condition. We attempted to explore the prevalence of positive clinical signs in patients with various organic neurological diseases. We performed a prospective uncontrolled observational study on the presence of 7 positive signs in adults with various organic neurological diseases that were admitted to our tertiary care hospital. This observation was performed during their neurological examination in those who provided consent, could comprehend and lacked terminal illness or profound weakness that limited their ability to perform these tasks. We dichotomized them into two groups based on the presence of these signs. Out of 190 patients that were evaluated between 2014 and 2015, 37 patients had at least one positive sign. On univariate analysis: young age, female gender, prior anxiety, history of childhood abuse, identification of sensory deficits on examination and lack of imaging correlation with clinical localization were identified as risk factors for these positive signs. On multivariate analysis, anxiety (OR 2.88, 95% CI 1.11-7.49, p = 0.03) and presence of sensory deficits on examination (OR 5.81, 95% CI 2.36-14.32, p ≤ 0.001) were associated with these positive signs. Positive signs are common in patients with organic neurological diseases that have anxiety or sensory deficits and may imply a component of functional overlay. Large studies are required to understand its pathophysiology and impact on future outcomes.

Processing of Emotion in Functional Neurological Disorder

Emotions have traditionally been considered crucial in the development of functional neurological disorder, but the evidence underpinning this association is not clear. We aimed to summarize evidence for association between functional neurological disorder and emotions as formulated by Breuer and Freud in their conception of hysterical conversion. Based on a systematic literature search, we identified 34 controlled studies and categorized them into four groups: (i) autonomic arousal, (ii) emotion-motion interactions, (iii) social modulation of symptoms, and (iv) bodily awareness in FND. We found evidence for autonomic dysregulation in FND; convergent neuroimaging findings implicate abnormal limbic-motor interactions in response to emotional stimuli in FND. Our results do not provide enough empirical evidence for social modulation of the symptoms, but there is a clinical support for the role of suggestion and placebo in FND. Our results provide evidence for abnormal bodily awareness in FND. Based on these findings, we propose that functional neurological symptoms are forms of emotional reactions shaped into symptoms by previous experience with illness and possibly reinforced by actual social contexts. Additional research should investigate the effect of social context on the intensity of functional neurological symptoms and associated brain regions.

Stressful life events and maltreatment in conversion (functional neurological) disorder: systematic review and meta-analysis of case-control studies

BACKGROUND

Stressful life events and maltreatment have traditionally been considered crucial in the development of conversion (functional neurological) disorder, but the evidence underpinning this association is not clear. We aimed to assess the association between stressors and functional neurological disorder.

METHODS

We systematically reviewed controlled studies reporting stressors occurring in childhood or adulthood, such as stressful life events and maltreatment (including sexual, physical abuse, and emotional neglect) and functional neurological disorder. We did a meta-analysis, with assessments of methodology, sources of bias, and sensitivity analyses.

FINDINGS

34 case-control studies, with 1405 patients, were eligible. Studies were of moderate-to-low quality. The frequency of childhood and adulthood stressors was increased in cases compared with controls. Odds ratios (OR) were higher for emotional neglect in childhood (49% for cases vs 20% for controls; OR 5·6, 95% CI 2·4-13·1) compared with sexual abuse (24% vs 10%; 3·3, 2·2-4·8) or physical abuse (30% vs 12%; 3·9, 2·2-7·2). An association with stressful life events preceding onset (OR 2·8, 95% CI 1·4-6·0) was stronger in studies with better methods (interviews; 4·3, 1·4-13·2). Heterogeneity was significant between studies (I² 21·1-90·7%). 13 studies that specifically ascertained that the participants had not had either severe life events or any subtype of maltreatment all found a proportion of patients with functional neurological disorder reporting no stressor.

INTERPRETATION

Stressful life events and maltreatment are substantially more common in people with functional neurological disorder than in healthy controls and patient controls. Emotional neglect had a higher risk than traditionally emphasised sexual and physical abuse, but many cases report no stressors. This outcome supports changes to diagnostic criteria in DSM-5; stressors, although relevant to the cause in many patients, are not a core diagnostic feature. This result has implications for ICD-11.

FUNDING

None.

Hepatic and hippocampal cytochrome P450 enzyme overexpression during spontaneous recurrent seizures

OBJECTIVE

Available evidence points to a role of cytochrome P450 (Cyp) drug biotransformation enzymes in central nervous system diseases, including epilepsy. Deviations in drug pharmacokinetic profiles may impact therapeutic outcomes. Here, we ask whether spontaneous recurrent seizure (SRS) activity is sufficient to modulate the expression of major Cyp enzymes in the liver and brain.

METHODS

Unilateral intrahippocampal (IH) kainic acid (KA) injections were used to elicit nonconvulsive status epilepticus (SE), epileptogenesis, and SRS, as monitored by video-electroencephalography. Intraperitoneal (IP) KA injection was used to trigger generalized tonic-clonic SE. KA-injected mice and sham controls were sacrificed at 24-72 hours and 1 week post-SE (IH or IP KA), and during the chronic stage (SRS; 6 weeks post-IH KA). Liver and brain tissues were processed for histology, real-time quantitative polymerase chain reaction, Western blot, or microsomal enzymatic assay. Cyp2e1, Cyp3a13, glial fibrillary acidic protein (GFAP), IBA1, xenobiotic nuclear receptors nr1i2 (PXR), nr1i3 (CAR) and nr3c1 (glucocorticoid receptor [GR]) expression was examined. Serum samples were obtained to assay corticosterone levels, a GR activator.

RESULTS

A significant increase of Cyp3a13 and Cyp2e1 transcript level and protein expression was found in the liver and hippocampi during SRS, as compared to control mice. In the ipsilateral hippocampus, Cyp2e1 and Cyp3a protein upregulation during SRS positively correlated to GFAP expression. GFAP⁺ , and not IBA1⁺ , cells colocalized with Cyp2e1 or Cyp3a expression. In the liver, a trend increase in Cyp3a microsomal activity was found during SRS as compared to control mice. The transcript levels of the Cyp upstream regulators GR, xenobiotic nr1i2, and nr1i3 receptors were unchanged at SRS. Corticosterone levels, a GR ligand, were increased in the blood post-SE.

SIGNIFICANCE

SRS modifies Cyp expression in the liver and the hippocampus. Nuclear receptors or inflammatory pathways are candidate mechanisms of Cyp regulation during seizures.

miR-212 mediates counter-regulation on CRH expression and HPA axis activity in male mice

The mechanisms of hypothalamic-pituitary-adrenal (HPA) axis regulation have been studied persistently but still are not elucidated. Considering the emerging roles of microRNA in stress response, we conducted a microRNA microarray in mice hypothalamus to identify the potential role of microRNAs in regulating the HPA axis. In total, 41 microRNAs changed during heat stress in which we found that miR-212 contains a binding sequence with corticotropin-releasing hormone (Crh) 3'UTR according to a sequence analysis. We observed that miR-212 expression in the hypothalamus was escalated by repeated heat and restraint stress. By overexpression or inhibition of miR-212 and the dual-luciferase reporter assay, we proved that miR-212 could bind with Crh 3'UTR to regulate its expression in mice hypothalamus primary cells and in the hippocampus neuron cell line HT-22. In addition, we injected miR-212 agomir or antagomir in mice hypothalamus to overexpress or inhibit miR-212, which leads to alterations of CRH expression and HPA axis activity in vivo Furthermore, miR-212 and CRH were both transcribed by the cAMP response element-binding protein (CREB). Overexpression and inhibition of miR-212 affect CREB-dependent CRH expression. Taken together, our results suggest an inhibitory role of miR-212 on the HPA axis, which acts in a counter-regulatory manner.

Somatoform dissociation and posttraumatic stress syndrome - two sides of the same medal? A comparison of symptom profiles, trauma history and altered affect regulation between patients with functional neurological symptoms and patients with PTSD

BACKGROUND

History of traumatic experience is common in dissociative disorder (DD), and similarity of symptoms and characteristics between DD and posttraumatic stress disorder (PTSD) encouraged to consider DD as trauma-related disorder. However, conceptualization of DD as a trauma-related syndrome would critically affect diagnosis and treatment strategies. The present study addressed overlap and disparity of DD and PTSD by directly comparing correspondence of symptoms, adverse/traumatic experience, and altered affect regulation between patients diagnosed with dissociative disorder (characterized by negative functional neurological symptoms) and patients diagnosed with PTSD.

METHODS

Somatoform and psychoform dissociation, symptoms of posttraumatic stress, general childhood adversities and lifetime traumata, and alexithymia as index of altered affect regulation were screened with standardized questionnaires and semi-structured interviews in 60 patients with DD (ICD-codes F44.4, F44.6, F44.7), 39 patients with PTSD (ICD-code F43.1), and 40 healthy comparison participants (HC).

RESULTS

DD and PTSD patients scored higher than HC on somatoform and psychoform dissociative symptom scales and alexithymia, and reported more childhood adversities and higher trauma load. PTSD patients reported higher symptom severity and more traumata than DD patients. Those 20 DD patients who met criteria of co-occuring PTSD did not differ from PTSD patients in the amount of reported symptoms of somatoform dissociation, physical and emotional childhood adversities and lifetime traumata, while emotional neglect/abuse in childhood distinguished DD patients with and without co-occuring PTSD (DD patients with co-occuring PTSD reporting more emotional maltreatment).

CONCLUSION

The pattern of distinctive somatoform and psychoform dissociative symptom severity, type of childhood and lifetime traumata, and amount of alexithymia suggests that DD and PTSD are distinctive syndromes and, therefore, challenges the conceptualization of DD as trauma-related disorder. Together with the detected close correspondence of symptom and experience profiles in DD patients with co-occuring PTSD and PTSD patients, these findings suggest that adverse/traumatic experience may intensify dissociative symptoms, but are not a necessary condition in the generation of functional neurological symptoms. Still, diagnosis and treatment of DD need to consider this impact of traumata and post-traumatic stress symptoms.