Attentional Processing and Interpretative Bias in Functional Neurological Disorder

The presence of attentional and interpretation biases in patients with severe MS-related fatigue

OBJECTIVE

Severe fatigue is a prevalent and disabling symptom in multiple sclerosis (MS). This study tested if a fatigue- and physical activity-related attentional bias (AB) and a somatic interpretation bias (IB) are present in severely fatigued patients with MS. Biases were compared to healthy controls and patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS).

METHOD

Severely fatigued patients with MS or ME/CFS and healthy controls completed a Visual Probe Task (VPT) assessing fatigue- and physical activity-related AB and an IB task that assesses the tendency to interpret ambiguous information in either a somatically threatening way or in a more neutral manner. The VPT was completed by 38 MS patients, 44 ME/CFS patients, and 46 healthy controls; the IB task was completed by 156, 40 and 46 participants respectively.

RESULTS

ANOVA showed no statistically significant group differences in a fatigue-related AB or physical activity-related AB (omnibus test of interaction between topic × condition: F2,125 = 1.87; p = .159). Both patient groups showed a tendency to interpret ambiguous information in a somatically threatening way compared to healthy controls (F1,2 = 27.61, p < .001). This IB was significantly stronger in MS patients compared to ME/CFS patients. IB was significantly correlated with cognitive responses to symptoms in MS patients.

CONCLUSION

MS patients tend to interpret ambiguous information in a somatically threatening way. This may feed into unhelpful ways of dealing with symptoms, possibly contributing to the perpetuation of severe fatigue in MS.

Understanding Functional Neurological Disorder: Recent Insights and Diagnostic Challenges

Functional neurological disorder (FND), formerly called conversion disorder, is a condition characterized by neurological symptoms that lack an identifiable organic purpose. These signs, which can consist of motor, sensory, or cognitive disturbances, are not deliberately produced and often vary in severity. Its diagnosis is predicated on clinical evaluation and the exclusion of other medical or psychiatric situations. Its treatment typically involves a multidisciplinary technique addressing each of the neurological symptoms and underlying psychological factors via a mixture of medical management, psychotherapy, and supportive interventions. Recent advances in neuroimaging and a deeper exploration of its epidemiology, pathophysiology, and clinical presentation have shed new light on this disorder. This paper synthesizes the current knowledge on FND, focusing on its epidemiology and underlying mechanisms, neuroimaging insights, and the differentiation of FND from feigning or malingering. This review highlights the phenotypic heterogeneity of FND and the diagnostic challenges it presents. It also discusses the significant role of neuroimaging in unraveling the complex neural underpinnings of FND and its potential in predicting treatment response. This paper underscores the importance of a nuanced understanding of FND in informing clinical practice and guiding future research. With advancements in neuroimaging techniques and growing recognition of the disorder's multifaceted nature, the paper suggests a promising trajectory toward more effective, personalized treatment strategies and a better overall understanding of the disorder.

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.

A New Experimental Design to Examine Cognitive Biases for Gastrointestinal Related Stimuli in Children and Adolescents

Cognitive biases toward disorder-specific stimuli are suggested as crucial to the development and maintenance of symptoms in adults with functional gastrointestinal disorders (FGID). Functional abdominal pain disorders (FAPD), a subtype of FGID, are common in children and adolescents, but the influence of cognitive biases is sparsely examined. This study aimed to (1) develop a new experimental design for assessing cognitive biases toward gastrointestinal stimuli in children and adolescents (aged 8 to 17 years) and (2) derive comparative data on bias toward gastrointestinal stimuli using a healthy "normative" sample. The online experimental design-BY-GIS (Bias in Youth toward GastroIntestinal-related Stimuli)-includes a word task and a picture task. Stimuli in both tasks are related to general and gastrointestinal symptoms, and the design includes three phases: (1) encoding, (2) free recall, and (3) recognition. Data were collected between April 2022 and April 2023 from 96 healthy participants (Mage = 12.32, 47.92% female). Adolescents were significantly better at recalling words than children (p = 0.03), whereas there were no significant gender or age differences with regard to recalling pictures (p > 0.05). Across age and gender, participants performed above chance level in the recognition phases of both tasks. The results support that the design is suitable within the age span.

Functional neurological disorder: Clinical manifestations and comorbidities; an online survey

Functional Neurological Disorder (FND) is common and is often accompanied by multiple comorbid symptoms and conditions. There have been no large-scale studies exploring the change of its clinical manifestations and comorbidities. We used an online survey to assess FND patient characteristics, changes to fatigue, sleep and pain and comorbid symptoms and diagnoses, as well as treatment strategies. The survey was shared via the charities FND Action and FND Hope. 527 participants were included in the analysis. Most (97.3%) reported experiencing more than one core FND symptom. Many respondents reported associated pain (78.1%), fatigue (78.0%) and sleep disturbances (46.7%) before FND diagnosis which often increased thereafter. Rates of obesity were higher (36.9%) than in the general population. Obesity was associated with increased pain, fatigue and sleep difficulties. There was frequent weight gain after diagnosis. 50.0% of participants reported having other diagnoses prior to FND, while in 43.3% new comorbidities arise after FND diagnosis. Many respondents reported being dissatisfied with their care, expressing a wish for further follow-up from mental health (32.7%) and/or neurological services (44.3%). This large online survey further supports the phenotypic complexity of FND. High rates of pain, fatigue and sleep disturbance exist before diagnosis but monitoring for change is worthwhile. Our study identified major gaps in service provision; we highlight the importance of an open mind regarding change in symptoms; this could aid the early identification and management of co-morbidities, including obesity and migraine, which possibly have a negative impact on FND.

Generalized Worry in Patients With Chronic Fatigue Syndrome Following Cognitive Behavioral Therapy: A Prospective Cohort Study in Secondary Care

Research has shown that generalized anxiety disorder is commonly associated with Chronic Fatigue Syndrome (CFS). This prospective cohort study aimed to investigate the prevalence of generalized worry in CFS patients and its relationship with fatigue, anxiety and social functioning, before and after Cognitive Behavioral Therapy (CBT). Our cohort consisted of 470 patients diagnosed with CFS who received CBT at a secondary care, specialist clinic. Patients completed self-report measures investigating levels of generalized worry, fatigue, work and social adjustment, anxiety and depression at baseline (pretreatment), discharge from treatment, 3-month and 6-month follow up (posttreatment). Analysis indicated a high prevalence of generalized worry (72.4%) at assessment. A significant reduction in worry following CBT (M = -3.42, p < .001, 95% CIs: 2.26, 4.57) was observed at discharge, which remained stable at follow-up. Severe baseline worriers had greater overall fatigue score (M = 3.74, p = .026, 95% CIs: .33, 7.15) and worse overall work and social adjustment than mild worriers across time-points (M = 5.42, p = .035 95% CIs: .27, 10.58). Avoidance behavior mediated the association between generalized worry and work and social adjustment (95% bootstrap CIs: 013, .080). The majority of patients with CFS had comorbid generalized worry and severe worriers reported greater fatigue, anxiety, and worse work and social adjustment. This suggests that CFS patients may benefit from targeting generalized worry during CBT.

Executive Functions and Attention in Patients With Psychogenic Nonepileptic Seizures Compared With Healthy Controls: A Cross-Sectional Study

OBJECTIVE

Psychogenic nonepileptic seizures (PNESs) are considered functional neurological symptoms and are highly prevalent in specialized epilepsy clinics. The underlying mechanisms of PNES are not fully understood. Recent findings point toward possible alterations in attention and executive functions. This study aimed to extend the current knowledge of attention and executive function in patients with PNES and to assess possible relationships between seizures and dissociation, childhood trauma, and cognitive function.

METHODS

We recruited 40 patients with PNES and 40 sex-, age-, and education-matched healthy controls (HCs) in this study. Participants completed self-report questionnaires to assess early life stress (Childhood Trauma Questionnaire [CTQ]), dissociation (the German version of the Dissociative Experience Scale, or Fragebogen zu dissoziativen Symptomen), and depression (Patient Health Questionnaire-9). Executive functions and attention were assessed with the Trail Making Test (TMT), Digit Span, and Attention Network Task.

RESULTS

Compared with HCs, patients with PNES reported significantly higher levels of childhood trauma, depression, and dissociation. Patients with PNES also had reduced performance indices for Digit Span Forward (d = 0.62), Digit Span Backward (d = 0.62), and TMT (d = 0.67) but not Attention Network Task. CTQ scores positively correlated with TMT and Digit Span Backward performance in patients with PNES. Adjusting for CTQ scores attenuated the observed group difference in TMT performance. Depression and dissociation did not explain the observed findings.

CONCLUSIONS

These results contribute to the evidence of impaired executive functions in patients with PNES. Furthermore, childhood trauma scores, but not (trait) dissociation or depression scores, seem to drive group differences (HC versus patients with PNES).

Hedonicity in functional motor disorders: a chemosensory study assessing taste

The aim of this study was to explore hedonicity to basic tastes in patients with functional motor disorders (FMDs) that are often associated with impairment in emotional processing. We recruited 20 FMD patients and 24 healthy subjects, matched for age and sex. Subjects were asked to rate the hedonic sensation (i.e., pleasant, neutral, and unpleasant) on a - 10 to +10 scale to the four basic tastes (sweet, sour, salty, and bitter) at different concentrations, and neutral stimuli (i.e., no taste stimulation) by means of the Taste Strips Test. Anxiety, depression, and alexithymia were assessed. FMD patients rated the highest concentration of sweet taste (6.7 ± 2.6) as significantly more pleasant than controls (4.7 ± 2.5, p = 0.03), and the neutral stimuli significantly more unpleasant (patients: - 0.7 ± 0.4, controls: 0.1 ± 0.4, p = 0.013). Hedonic ratings were not correlated to anxiety, depression, or alexithymia scores. Hedonic response to taste is altered in FMD patients. This preliminary finding might result from abnormal interaction between sensory processing and emotional valence.