Altered self-processing brain networks in paediatric functional neurological disorder

Abstract

Objectives: Functional neurological disorder (FND) is associated with altered self-processing - the neural processes that underpin the individual's self-agency and sense of self. This study used resting-state functional magnetic resonance imaging to examine three nested meta-analytically defined self-processing brain networks in 28 children with mixed FND symptoms and 31 healthy controls.

Methods: Regions of interest (ROIs) for each layer of brain network analysis were defined using the nested hierarchical model of self-processing developed by Northoff and colleagues specifying the insula (interoceptive processing), temporoparietal junction [TPJ] (exteroceptive processing), and anterior medial prefrontal cortex [amPFC] (mental-self processing) as seed ROIs. Connectivity differences for each layer of self-processing were examined with ROI-to-ROI analysis. Correlation analyses were conducted in relation to adverse childhood experiences (ACEs) and arousal (resting heart rate).

Results: At the mental-self layer, children with FND (vs. controls) had increased functional connectivity between the amPFC and thalamus and left dorsolateral prefrontal cortex (dlPFC). Children with functional seizures (vs. other FND symptoms) had decreased functional connectivity between the amPFC and right TPJ. At the interoceptive layer, the FND group showed a positive correlation between ACEs and functional connectivity between the left insula seed and right TPJ and dorsal anterior cingulate cortex (dACC). There were no findings at the exteroceptive layer of self-processing.

Conclusions: Our findings suggest that ACEs (including trauma) are associated with altered self-processing in brain networks in children with FND. Further examination of self-processing is likely to prove a fruitful endeavour both in therapy and in future FND research.

Keywords: Adverse childhood experiences (ACEs); Conversion disorder; Functional neurological disorder; Resting-state functional magnetic resonance imaging; Self-processing; Trauma.

Fig. 1

Layers of self-processing brain networks from Qin et al., 2020. The figure depicts the hierarchical nesting of insula (in all three layers) and TPJ (in exteroceptive and mental-self layer). Each layer is anchored by seed ROIs in corresponding colour, displayed on cortical surface on the right of the figure. Each ROI is a 10 mm sphere defined at coordinates from Qin et al., 2020.

Fig. 2

Visual representation of FND subtypes experienced by the children in the study cohort. Children with mixed FND commonly present with multiple functional neurological symptoms which fall under four main subtypes: functional seizures, negative motor symptoms, positive motor symptoms, and sensory symptoms.

Fig. 3

Increased functional connectivity in the mental-self layer between the amPFC (seed ROI) and both the thalamus and the left dlPFC in children with FND versus healthy controls, when controlling for depression, anxiety, and stress (total DASS).

Fig. 4

Decreased functional connectivity in the mental-self layer between the amPFC and the right TPJ in children with functional seizures (FND-seizure group) versus children with other FND symptoms (FND-other group).

Fig. 5

Association between interoceptive layer left insula connectivity and ACEs (total ELSQ) for children with FND, captured by linear regression, corrected for multiple comparisons (a). Functional connectivity between the left insula and both the right TPJ and dACC positively correlated with ACEs in children with FND (but not in controls), captured by pearson correlations (b).

Fig. 6

Association between interoceptive layer left insula connectivity and physiological arousal (resting HR) in children with FND, captured by linear regression, trend-level significance when corrected for multiple comparisons (a). Positive correlation between the left insula seed and a left insula target functional connectivity and physiological arousal (resting HR), captured by pearson correlation (b).