Neurocognitive functioning in patients with conversion disorder/functional neurological disorder

Neurocognitive performance in functional neurological disorder: A systematic review and meta-analysis

BACKGROUND AND PURPOSE

Cognitive complaints are common in functional neurological disorder (FND), but it is unclear whether objective neurocognitive deficits are present. This systematic review summarized validated/standardized cognitive test performance in FND samples across cognitive domains.

METHODS

Embase, PsycInfo and MEDLINE were searched from inception to 15 May 2023, combining terms for FND and cognitive domains (e.g., attention, memory, executive functioning). Studies included a range of FND phenotypes (seizures, motor, cognitive disorder, mixed), compared to healthy or clinical controls. Risk of bias was assessed with the modified Newcastle-Ottawa Scale and a qualitative synthesis/narrative review of cognitive performance in FND was conducted. Test performance scores were extracted, and random effects meta-analyses were run where appropriate. This review was registered on PROSPERO, CRD42023423139.

RESULTS

Fifty-six studies including 2260 individuals with FND were eligible. Although evidence for some impairments emerged across domains of executive functioning, attention, memory and psychomotor/processing speed, this was inconsistent across studies and FND phenotypes. Common confounds included group differences in demographics, medication and intellectual functioning. Only 24% of studies objectively assessed performance validity. Meta-analyses revealed higher scores on tests of naming (g = 0.67, 95% confidence interval [CI] 0.50, 0.84) and long-term memory (g = 0.43, 95% CI 0.13, 0.74) in functional seizures versus epilepsy, but no significant differences in working (g = -0.08, 95% CI -0.44, 0.29) or immediate (g = 0.25, 95% CI -0.02, 0.53) memory and cognitive flexibility (g = -0.01, 95% CI -0.29, 0.28).

CONCLUSIONS

There is mixed evidence for objective cognitive deficits in FND. Future research should control for confounds, include tests of performance validity, and assess relationships between objective and subjective neurocognitive functioning.

Sensory Processing Difficulties and Occupational Therapy Outcomes for Functional Neurological Disorder: A Retrospective Cohort Study

Background and Objectives

Occupational therapy (OT) consensus recommendations and articles outlining a sensory-based OT intervention for functional neurological disorder (FND) have been published. However, limited research has been conducted to examine the efficacy of OT interventions for FND. We performed a retrospective cohort study aimed at independently replicating preliminarily characterized sensory processing difficulties in patients with FND and reporting on clinical outcomes of a sensory-based OT treatment in this population. We hypothesized that (1) a history of functional seizures, anxiety, and/or post-traumatic stress disorder would be associated with increased sensory processing difficulties and (2) the number of OT treatment sessions received would positively relate to clinical improvement.

Methods

Medical records were reviewed for 77 consecutive adults with FND who received outpatient, sensory-based OT care. Data from the Adolescent/Adult Sensory Profile characterized self-reported sensory processing patterns across 4 quadrants (low registration, sensory sensitivity, sensory seeking, and sensory avoidance) in this population. Following univariate screenings, multivariate linear regression analyses were performed to identify neuropsychiatric characteristics associated with discrete sensory processing patterns. Clinical improvement was quantified using an estimated, clinician-determined improvement rating ("improved" vs "not improved"), and relationships between clinical participation, baseline neuropsychiatric factors, and outcomes were investigated.

Results

Patients with FND reported sensory processing patterns with elevated scores in low registration, sensory sensitivity, and sensation avoidance compared with normative values; differences in sensory processing scores were not observed across FND subtypes (i.e., motor, seizure, and speech variants). In linear regression analyses, lifetime history of an anxiety disorder, history of migraine headaches, current cognitive complaints, and a comorbid major neurologic condition independently predicted individual differences in sensory processing scores. Following a sensory-based OT intervention, 62% of individuals with FND were clinician determined as "improved." In a multivariate logistic regression analysis controlling for baseline characteristics associated with improvement ratings, number of treatment sessions positively correlated with clinical improvement.

Discussion

These findings support the presence of sensory processing difficulties in patients with FND and provide Class IV evidence for the efficacy of an outpatient, sensory-based OT intervention in this population. Controlled prospective trials are warranted.

The role of neuropsychology in the care of patients with functional neurological symptom disorder

OBJECTIVE

Functional neurological symptom disorder (FNSD) is a neuropsychiatric condition characterized by signs/symptoms associated with brain network dysfunction. FNSDs are common and are associated with high healthcare costs. FNSDs are relevant to neuropsychologists, as they frequently present with chronic neuropsychiatric symptoms, subjective cognitive concerns, and/or low neuropsychological test scores, with associated disability and reduced quality of life. However, neuropsychologists in some settings are not involved in care of patients with FNSDs. This review summarizes relevant FNSD literature with a focus on the role of neuropsychologists.

METHODS

A brief review of the literature is provided with respect to epidemiology, public health impact, symptomatology, pathophysiology, and treatment.

RESULTS

Two primary areas of focus for this review are the following: (1) increasing neuropsychologists' training in FNSDs, and (2) increasing neuropsychologists' role in assessment and treatment of FNSD patients.

CONCLUSIONS

Patients with FNSD would benefit from increased involvement of neuropsychologists in their care.

Objective and subjective neurocognitive functioning in functional motor symptoms and functional seizures: preliminary findings

INTRODUCTION

This study aimed to provide a preliminary assessment of objective and subjective neurocognitive functioning in individuals with functional motor symptoms (FMS) and/or functional seizures (FS). We tested the hypotheses that the FMS/FS group would display poorer objective attentional and executive functioning, altered social cognition, and reduced metacognitive accuracy.

METHOD

Individuals with FMS/FS (n = 16) and healthy controls (HCs, n = 17) completed an abbreviated CANTAB battery, and measures of intellectual functioning, subjective cognitive complaints, performance validity, and comorbid symptoms. Subjective performance ratings were obtained to assess local metacognitive accuracy.

RESULTS

The groups were comparable in age (p = 0.45), sex (p = 0.62), IQ (p = 0.57), and performance validity (p-values = 0.10-0.91). We observed no impairment on any CANTAB test in this FMS/FS sample compared to HCs, although the FMS/FS group displayed shorter reaction times on the Emotional Bias task (anger) (p = 0.01, np2 = 0.20). The groups did not differ in subjective performance ratings (p-values 0.15). Whilst CANTAB attentional set-shifting performance (total trials/errors) correlated with subjective performance ratings in HCs (p-values<0.005, rs = -0.85), these correlations were non-significant in the FMS/FS sample (p-values = 0.10-0.13, rs-values = -0.46-0.50). The FMS/FS group reported more daily cognitive complaints than HCs (p = 0.006, g = 0.92), which were associated with subjective performance ratings on CANTAB sustained attention (p = 0.001, rs = -0.74) and working memory tests (p < 0.001, rs = -0.75), and with depression (p = 0.003, rs = 0.70), and somatoform (p = 0.003, rs = 0.70) and psychological dissociation (p-values<0.005, rs-values = 0.67-0.85).

CONCLUSIONS

These results suggest a discordance between objective and subjective neurocognitive functioning in this FMS/FS sample, reflecting intact test performance alongside poorer subjective cognitive functioning. Further investigation of neurocognitive functioning in FND subgroups is necessary.

Personality traits related to cognitive functioning in patients with functional neurological disorder

Cognitive symptoms are prevalent in patients with functional neurological disorder (FND). Several studies have suggested that personality traits such as neuroticism may play a pivotal role in the development of FND. FND has also been associated with alexithymia: patients with FND report difficulties in identifying, analyzing, and verbalizing emotions. Whether or not alexithymia and other personality traits are associated with cognitive symptomatology in patients with FND is unknown. In the current study, we explored whether the Big Five personality model factors (neuroticism, extraversion, openness, agreeableness, and conscientiousness) and alexithymia were associated with cognitive functioning in FND. Twenty-three patients with FND were assessed using a neuropsychological assessment and questionnaire assessment to explore personality traits (Neuroticism-Extraversion-Openness Five-Factor Inventory) and alexithymia (Bermond-Vorst Alexithymia Questionnaire). The results indicated that high conscientiousness was associated with lower planning scores (ρ = -0.52, p = .012) and high scores on alexithymia were associated with lower scores on verbal memory scores (ρ = -0.46, p = .032) and lower sustained attention scores (ρ = -0.45, p = .046). The results did not remain significant after controlling for multiple testing. The preliminary results of our study suggest that personality and cognitive symptomatology in patients with FND are topics that should be further explored in future studies, as cognitive symptomology can affect treatment results.

Psychiatrists' attitudes towards functional neurological disorders: results from a national survey

Introduction

Functional neurological disorder (FND) presents motor, sensory, and cognitive symptoms characterized by clinical signs incongruent with known neurological disease. Together with other health professionals, like neurologists, psychiatrists can play an essential role in diagnosing and managing these disorders. Hence, understanding their opinion and clinical experience with FND is of utmost importance to catch potential educational needs and improve healthcare services for patients. This study aims at assessing the knowledge, opinion, and clinical approach of Italian psychiatrists to FND.

Methods

Members of the Italian Society of Psychiatry completed a 14-item web-based survey investigating their approach to FND. Results. Overall, 174 questionnaires were completed. Our main findings suggest that Italian psychiatrists have a psychogenetic conceptualization of FND. "Conversion disorders", in fact, is the term most frequently used by Italian psychiatrists to refer to FND, thus implying a psychological etiology of these disorders. Congruently with this view, psychotherapy associated with pharmacological therapy is considered the most appropriate treatment by psychiatrists, while physiotherapy is an under-recognized treatment option for FND.

Discussion

The present study highlights that a psychogenetic view of FND dominates among Italian psychiatrists. This could be due to out-of-date knowledge about the pathophysiology of this group of disorders. Promoting education about novel approaches to FND would be of crucial importance to improving care for patients suffering from this condition.

Personality factors and cognitive functioning in patients with somatic symptom and related disorders

OBJECTIVE

Somatic symptom and related disorders (SSRD) are often complicated by cognitive symptoms, including reduced information processing speed, memory, and planning. Depression has been related to poor cognitive functioning in SSRD, but the role of underlying personality factors is poorly understood. This study investigates the association between personality factors (neuroticism, extraversion, openness, agreeableness, and conscientiousness) with cognitive functioning in patients with SSRD.

METHODS

Data from 366 patients with SSRD from a tertiary care expert center (mean age = 42.1 years (SD = 13.4), 59.6% women) were analyzed using a cross-sectional design. Neuropsychological assessments included measures of information processing speed, memory, attention, and executive function. Personality factors were assessed using the NEO-FFI and depressive symptoms using the PHQ-9.

RESULTS

Regression analyses showed associations between neuroticism with poorer performance on visual memory (B = -0.09, SE = 0.04, β = -0.14, p = .019), and planning (B = -0.09. SE = 0.02, β = -0.23, p < .001). Extraversion was also inversely associated with visual memory (B = -0.13, SE = 0.05, β = -0.18, p = .011) and planning (B = -0.07, SE = 0.03, β = -0.17, p = .021) and openness was associated with better visual memory (B = 0.17, SE = 0.05, β = 0.19, p = .002). These associations were attenuated but remained significant after adjusting for depressive symptoms.

CONCLUSION

Neuroticism, extraversion, and low openness were associated with lower cognitive functioning (particularly planning and visual memory) in patients with SSRD, which remained significant after taking depressive symptoms into account.

A Longitudinal Study on Attenuated Structural Covariance in Patients With Somatic Symptom Disorder

OBJECTIVE

This study was performed to investigate altered regional gray matter volume (rGMV) and structural covariance related to somatic symptom disorder (SSD) and longitudinal changes after treatment. Additionally, this study examined the relationships of structural alteration with its phenotypic subtypes.

METHODS

Forty-three unmedicated patients with SSD and thirty normal controls completed psychological questionnaires and neurocognitive tests, as well as brain magnetic resonance imaging. Voxel-based morphometry and structural covariances were compared between groups and between subgroups within the SSD group. After 6 months of treatment, SSD patients were followed up for assessments.

RESULTS

Patients with SSD exhibited attenuated structural covariances in the pallidal-cerebellar circuit (FDR < 0.05-0.1), as well as regions in the default mode and sensorimotor network (FDR < 0.2), compared to normal controls. The cerebellar rGMVs were negatively correlated with the severity of somatic symptoms. In subgroup analyses, patients with somatic pain showed denser structural covariances between the bilateral superior temporal pole and left angular gyrus, the left middle temporal pole and left angular gyrus, and the left amygdala and right inferior orbitofrontal gyrus, while patients with headache and dizziness had greater structural covariance between the right inferior temporal gyrus and right cerebellum (FDR < 0.1-0.2). After 6 months of treatment, patients showed improved symptoms, however there was no significant structural alteration.

CONCLUSION

The findings suggest that attenuated structural covariance may link to dysfunctional brain network and vulnerability to SSD; they also suggested that specific brain regions and networks may contribute to different subtypes of SSD.

The relationships between cognitive control and psychological symptoms in patients with somatic symptom disorder: a pilot longitudinal study

INTRODUCTION

The present study explored how neurocognitive function correlated with the clinical symptoms of somatic symptom disorder (SSD) by evaluating changes in cognitive abilities according to differences in relevant factors.

METHODS

A total of 44 patients with SSD and 30 healthy controls completed tests assessing various neurocognitive domains, including verbal memory, psychomotor speed, executive function, working memory, and sustained and divided attention. They also completed questionnaires for psychological assessment. The same tests and questionnaires were completed by 26 SSD patients 6 months later.

RESULTS

The SSD patients had significantly lower scores on the attentional and verbal memory tests than did the healthy controls. Performance on the attentional test was significantly associated with the level of somatic symptoms and anxiety. The follow-up assessment results of the SSD patients revealed improved performance on the verbal learning and fluency tests as well as improvements in somatic symptoms, anxiety, and depression. It was also observed that changes in verbal learning and attentional functions were significantly associated with improvements in somatic symptoms.

CONCLUSIONS

The present study suggests that neurocognitive dysfunctions are subtle and not specific to SSD, but certain cognitive functions may be related to the clinical symptoms and improvements of patients with SSD.

Assessment of cytokines, microRNA and patient related outcome measures in conversion disorder/functional neurological disorder (CD/FND): The CANDO clinical feasibility study

BACKGROUND

Conversion disorder/functional neurological disorder (CD/FND) occurs often in neurological settings and can lead to long-term distress, disability and demand on health care services. Systemic low-grade inflammation might play a role, however, the pathogenic mechanism is still unknown.

AIM

1) To explore the feasibility to establish and assess a cohort of CD/FND with motor symptoms, involving persons with lived experience (PPI). 2) To generate proof of concept regarding a possible role for cytokines, microRNA, cortisol levels and neurocognitive symptoms in patients with motor CD/FND.

METHOD

Feasibility study.

RESULTS

The study showed active involvement of patients despite high clinical illness burden and disability, neurocognitive symptoms, childhood adverse experiences (ACE) and current life events. The study provided valuable knowledge regarding the feasibility of conducting a study in these patients that will inform future study phases. In the sample there were elevated levels of IL6, IL12, IL17A, IFNg, TNFa and VEGF-a, suggesting systemic low-grade inflammation. Also, microRNAs involved in inflammation and vascular inflammation were correlated with TNFa and VEGFa respectively, suggesting proof of concept for an epigenetic mechanism. Owing to the COVID-19 outbreak, the patient sample was limited to 15 patients.

CONCLUSION

It is a novelty that this study is conducted in the clinical setting. This innovative, translational study explores stress-related SLI in CD/FND patients and the feasibility of a larger project aiming to develop new treatments for this vulnerable population. Given the positive findings, there is scope to conduct further research into the mechanism of disease in CD/FND.

[Functional neurological disorders]

This paper reviews the literature on functional neurological disorders (Dissociative (conversion disorders - F44). The authors present a change in views on the etiology and the main mechanisms of the pathogenesis of this pathology during the period of its study. The modern ideas about the types of cerebral dysfunction characteristic of functional neurological disorders are considered. The description of the most characteristic mental and somatic symptoms observed in dissociative disorders and the features of their clinical manifestations are given. The current approaches to the therapy of functional neurological disorders are considered.

Psychometric Properties of the Chinese Version of the Cognitions About Body and Health Questionnaire

INTRODUCTION

The Cognitions About Body and Health Questionnaire (CABAH) is a self-rating questionnaire measuring cognitions about health. The psychometric properties of its Chinese version and its performance on evaluating somatic symptom disorder (SSD) were examined in this study.

METHODS

After translating the CABAH into Chinese, we collected data of the CABAH and another four questionnaires (Patient Health Questionnaire-15, Health Anxiety Questionnaire, Beck Depression Inventory-II, Beck Anxiety Inventory) in 208 SSD patients and 197 healthy individuals. We used exploratory factor analysis (EFA) to explore the structure of the Chinese CABAH. Internal consistency and criterion-related validity were analyzed. An independent t-test and receiver operating characteristic (ROC) curve analysis were used to evaluate the performance of the CABAH for evaluating SSD.

RESULTS

Six factors were suggested by EFA. Five (bodily weakness, health habits, catastrophizing interpretation of specific bodily complaints, somatosensory amplification, catastrophizing interpretation of general bodily complaints) are conceptually associated with the original CABAH. The sixth factor (reverse, with three items) is different from the original construct. Cronbach's alpha for the CABAH was 0.885. The CABAH score was moderately correlated with scores of the other four questionnaires. Scores for the whole CABAH and scores of the six factors were all significantly higher in SSD patients than in healthy individuals. The results of ROC curve analysis were as follows: area under the curve=0.700; suggested cutoff=58/59; Youden's J=0.295.

CONCLUSION

The reliability and validity of the Chinese CABAH were fair, although the three items in the reverse factor should be interpreted cautiously.

Gray Matter Density of the Dorsomedial Prefrontal Cortex Mediates the Relationship Between Catastrophizing and Anxiety in Somatic Symptom Disorder

OBJECTIVE

Catastrophizing is commonly co-occurrence with anxiety in somatic symptom disorder (SSD). However, the quantitative relationship between catastrophizing and anxiety in SSD and its underlying neuropsychopathology remains unclear.

METHODS

To address the issue, twenty-eight SSD patients and twenty-nine healthy controls (HCs) completed the Hamilton anxiety scale and the catastrophizing subscale of the cognitive emotion regulation questionnaire. Then they underwent structural magnetic resonance imaging and voxel-based morphometry analysis was performed to obtain gray matter density (GMD) of the dorsomedial prefrontal cortex (dmPFC).

RESULTS

Independent samples t-tests showed no significance between SSD patients and HCs in the scores on the catastrophizing subscale and GMD of the dmPFC. However, correlation analysis found that catastrophizing was significantly positively associated with anxiety in SSD. Further, mediation analyses revealed that GMD of the dmPFC (bilateral medial Brodmann area 8) mediated the relationship between catastrophizing and anxiety in SSD.

CONCLUSION

These findings support Kirmayer's disease model of SSD that catastrophic interpretations of somatic symptoms resulted in increased anxiety and demonstrate that the dmPFC may be a potential neural site linking catastrophizing and anxiety in SSD.

Psychogenic Pseudosyncope: Clinical Features, Diagnosis and Management

Psychogenic Pseudosyncope (PPS) is the appearance of Transient Loss of Consciousness (TLOC) in which movements are absent, but there are no hemodynamic and electroencephalographic modifications as are induced by gravitational challenges which characterize syncope and true loss of consciousness. For younger and adult populations, a detailed history is crucial for the diagnosis. Clinical clues that should raise the suspicion for PPS include prolonged duration of the LOC, eye closure during the episode, unusual triggers, no recognizable prodromes and the high frequency of attacks. The presence of an established diagnosis of syncope should not deter from the concomitant diagnosis of PPS. The gold standard for a proper diagnosis of PPS is the documentation by a tilt test of normal hemodynamic and electroencephalographic parameters, when recorded during an attack. Treatment of PPS, based on the clear and empathetic communication of the diagnosis, can lead to an immediate reduction of attack frequency and lower the need to call on emergency services. Pharmacological treatment of associated psychiatric disorders and psychological interventions may be beneficial in patients with PPS. Cognitive-behavioural therapy holds the most reliable evidence of efficacy. In the present review, we aimed to address PPS with historical aspects, main clinical features and diagnostic tests, current diagnostic classification, underlying neurobiological abnormalities, management and therapy.

Activation of Functional Brain Networks in Children With Psychogenic Non-epileptic Seizures

Objectives

Psychogenic non-epileptic seizures (PNES) have been hypothesized to emerge in the context of neural networks instability. To explore this hypothesis in children, we applied a graph theory approach to examine connectivity in neural networks in the resting-state EEG in 35 children with PNES, 31 children with other functional neurological symptoms (but no PNES), and 75 healthy controls.

Methods

The networks were extracted from Laplacian-transformed time series by a coherence connectivity estimation method.

Results

Children with PNES (vs. controls) showed widespread changes in network metrics: increased global efficiency (gamma and beta bands), increased local efficiency (gamma band), and increased modularity (gamma and alpha bands). Compared to controls, they also had higher levels of autonomic arousal (e.g., lower heart variability); more anxiety, depression, and stress on the Depression Anxiety and Stress Scales; and more adverse childhood experiences on the Early Life Stress Questionnaire. Increases in network metrics correlated with arousal. Children with other functional neurological symptoms (but no PNES) showed scattered and less pronounced changes in network metrics.

Conclusion

The results indicate that children with PNES present with increased activation of neural networks coupled with increased physiological arousal. While this shift in functional organization may confer a short-term adaptive advantage-one that facilitates neural communication and the child's capacity to respond self-protectively in the face of stressful life events-it may also have a significant biological cost. It may predispose the child's neural networks to periods of instability-presenting clinically as PNES-when the neural networks are faced with perturbations in energy flow or with additional demands.