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

ABSTRACT

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, r_s = −0.85), these correlations were non-significant in the FMS/FS sample (p-values = 0.10–0.13, r_s-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, r_s = −0.74) and working memory tests (p < 0.001, r_s = −0.75), and with depression (p = 0.003, r_s = 0.70), and somatoform (p = 0.003, r_s = 0.70) and psychological dissociation (p-values<0.005, r_s-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.

KEYWORDS:

• Cognitive
• functional neurological disorder
• conversion disorder
• psychogenic non-epileptic seizures
• functional movement disorder
• attention
• memory
• metacognition
• neuropsychological
• executive

Acknowledgments

Thank you to our FND Patient and Carer Advisory Panel, all participants, FND Hope UK and FND Action for supporting the project. Thanks also to Emily Ward for contributions to data processing. For the purposes of open access, the author has applied a Creative Commons Attribution (CC BY) licence to any Accepted Author Manuscript version arising from this submission.

Author contributions (CRediT)

Funding acquisition: SP (lead), MH, TC (supporting). Conceptualisation: SP (lead), MH, TC (supporting). Design/methodology: SP (lead), TC, MH, JSW, MJE, LHG, MAM, TRN, AATSR, ASD (supporting). Investigation: SP (lead: recruitment/screening, data collection), BS (supporting: recruitment/screening). Data curation (processing/preparation): LSMM, YS, ES. Formal data analysis: SP (lead), LSMM (supporting). Supervision: SP(lead), TC, MH, JSW, MJE, LHG, TC, MAM, TRN, AATSR, ASD (supporting). Validation: SP (lead), LSMM (supporting). Project administration: SP. Resources: SP (lead), MH, TC (supporting). Writing: SP (lead: original draft/review and editing), TC, JSW, MJE, LHG, MAM, LSMM (supporting: review and editing). All authors reviewed and approved the final version of the manuscript.

Data availability

Data available on reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/13803395.2023.2245110

Additional information

Funding

The study was funded by a Medical Research Council Career Development Award to SP [MR/V032771/1]. This paper represents independent research part-funded by the National Institute for Health and Care Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.