Reduction of autonomic regulation in children and adolescents with conversion disorders

Biological and perceived stress in motor functional neurological disorders

BACKGROUND

Current models explaining motor functional neurological disorders (FND) integrate both the neurobiological mechanisms underlying symptoms production and the role of psychosocial stressors. Imaging studies have suggested abnormal motor control linked to impaired emotional and stress regulation. However, little is known on the biological stress regulation in FND. Our aim was to study the biological and perceived response to stress in patients with motor FND.

METHODS

Sixteen patients with motor FND (DSM-5 criteria) and fifteen healthy controls underwent the Trier Social Stress Test. Hypothalamo-pituitary-adrenal axis (HPA) response was evaluated with salivary cortisol and autonomous sympathetic response with salivary alpha-amylase. Area under the curve was computed to reflect background levels (AUCg) and change over time (AUCi). Life adversities and perceived subjective stress on a visual analog scale (VAS) were correlated with biological responses.

RESULTS

FND patients had significantly higher background levels (AUCg) of both stress markers (cortisol and amylase) than controls. The biological response (AUCi) to stress did not differ between groups for both markers but the subjective response showed an interaction effect with patients reporting higher levels of stress than controls. After stress, controls showed a strong correlation between subjective and objective sympathetic values (amylase) but not patients. The number and subjective impact of adverse life events correlated with cortisol AUCg in patients only.

CONCLUSION

This study confirms a baseline HPA-axis and sympathetic hyperarousal state in motor FND related to life adversities. During a social stress, dissociation between perceived stress and biological markers was observed in patients only, reflecting a dysregulation of interoception capacity, which might represent an endophenotype of this disorder.

When things get complicated: At-risk attachment in children and adolescents with chronic pain

Pain is a signal of danger, and danger activates the attachment system. When a parent responds to a child's pain with appropriate protection and comfort, more often than not, the pain resolves. But what happens in families when a child's pain becomes chronic and continues to signal a danger that has long passed? This study explored patterns of attachment in 48 children and adolescents with chronic functional pain and 48 healthy controls using structured attachment interviews. Patterns of attachment were identified using the Dynamic Maturational Model of Attachment. Compared to controls, children and adolescents with chronic functional pain were classified into at-risk patterns of attachment (χ² = 76.4, df = 2, p < .001) and had higher rates of unresolved loss and trauma (χ² = 10.8, df = 1, p = .001), suggesting a long-standing history of relational stress and the disruption of nurturing relationships. The findings suggest that the quality of attachment relationships contribute to the development and maintenance of chronic functional pain. Ongoing anxiety within the attachment relationship, combined with unresolved loss and trauma, may function much like catastrophising, contributing to chronic functional pain by activating the body's arousal systems. The assessment process for chronic functional pain should include a family assessment to identify ruptures in attachment relationships, as well as unresolved loss and trauma events that need to be addressed through family interventions or individual therapy.

Identification of biotypes in Attention-Deficit/Hyperactivity Disorder, a report from a randomized, controlled trial

Attention-Deficit/Hyperactivity Disorder (ADHD) is a heterogeneous disorder. Current subtypes lack longitudinal stability or prognostic utility. We aimed to identify data-driven biotypes using multiple cognitive measures, then to validate these biotypes using EEG, ECG, and clinical response to atomoxetine as external validators. Study design was a double-blind, randomized, placebo-controlled crossover trial of atomoxetine including 116 subjects ages 6 through 17 with diagnosis of ADHD and 56 typically developing controls. Initial features for unsupervised machine learning included a cognitive battery with 20 measures affected in ADHD. External validators included baseline mechanistic validators (using electroencephalogram/EEG and electrocardiogram/ECG) and clinical response (ADHD Rating Scale and correlation with cognitive change). One biotype, labeled impulsive cognition, was characterized by increased errors of commission and shorter reaction time, had greater EEG slow wave (theta/delta) power and greater resting heart rate. The second biotype, labeled inattentive cognition, was characterized by longer/more variable reaction time and errors of omission, had lower EEG fast wave (beta) power, resting heart rate that did not differ from controls, and a strong correlation (r = -0.447, p < 0.001) between clinical response to atomoxetine and improvement in verbal memory immediate recall. ADHD comprises at least two biotypes that cut across current subtype criteria and that may reflect distinct arousal mechanisms. The findings provide evidence that further investigation of cognitive subtypes may be at least as fruitful as symptom checklist-based subtypes for development of biologically-based diagnostics and interventions for ADHD.

An Attachment-Based Model of the Relationship Between Childhood Adversity and Somatization in Children and Adults

OBJECTIVE

An attachment model was used to understand how maternal sensitivity and adverse childhood experiences are related to somatization.

METHODS

We examined maternal sensitivity at 6 and 18 months and somatization at 5 years in 292 children in a longitudinal cohort study. We next examined attachment insecurity and somatization (health anxiety, physical symptoms) in four adult cohorts: healthy primary care patients (AC1, n = 67), ulcerative colitis in remission (AC2, n = 100), hospital workers (AC3, n = 157), and paramedics (AC4, n = 188). Recall of childhood adversity was measured in AC3 and AC4. Attachment insecurity was tested as a possible mediator between childhood adversity and somatization in AC3 and AC4.

RESULTS

In children, there was a significant negative relationship between maternal sensitivity at 18 months and somatization at age 5 years (B = -3.52, standard error = 1.16, t = -3.02, p = .003), whereas maternal sensitivity at 6 months had no significant relationship. In adults, there were consistent, significant relationships between attachment insecurity and somatization, with the strongest findings for attachment anxiety and health anxiety (AC1, β = 0.51; AC2, β = 0.43). There was a significant indirect effect of childhood adversity on physical symptoms mediated by attachment anxiety in AC3 and AC4.

CONCLUSIONS

Deficits in maternal sensitivity at 18 months of age are related to the emergence of somatization by age 5 years. Adult attachment insecurity is related to somatization. Insecure attachment may partially mediate the relationship between early adversity and somatization.

Grey matter abnormalities in children and adolescents with functional neurological symptom disorder

Objective

Functional neurological symptom disorder refers to the presence of neurological symptoms not explained by neurological disease. Although this disorder is presumed to reflect abnormal function of the brain, recent studies in adults show neuroanatomical abnormalities in brain structure. These structural brain abnormalities have been presumed to reflect long-term adaptations to the disorder, and it is unknown whether child and adolescent patients, with illness that is typically of shorter duration, show similar deficits or have normal brain structure.

Method

High-resolution, three-dimensional T1-weighted magnetic resonance images (MRIs) were acquired in 25 patients (aged 10–18 years) and 24 healthy controls. Structure was quantified in terms of grey matter volume using voxel-based morphometry. Post hoc, we examined whether regions of structural difference related to a measure of motor readiness to emotional signals and to clinical measures of illness duration, illness severity, and anxiety/depression.

Results

Patients showed greater volumes in the left supplementary motor area (SMA) and right superior temporal gyrus (STG) and dorsomedial prefrontal cortex (DMPFC) (corrected p < 0.05). Previous studies of adult patients have also reported alterations of the SMA. Greater SMA volumes correlated with faster reaction times in identifying emotions but not with clinical measures.

Conclusions

The SMA, STG, and DMPFC are known to be involved in the perception of emotion and the modulation of motor responses. These larger volumes may reflect the early expression of an experience-dependent plasticity process associated with increased vigilance to others' emotional states and enhanced motor readiness to organize self-protectively in the context of the long-standing relational stress that is characteristic of this disorder.

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We used high-resolution MRI to investigate brain structure in children presenting with acute functional neurological symptom disorder (FND).

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Patients had multiple antecedent stressors, a long-standing history of relational stress and at-risk attachment strategies.

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Patients had greater volumes in the SMA—where motor-, cognitive-, and emotion-processing signals interact to influence motor function.

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FND may involve experience-dependent changes in brain structure alongside experience-dependent changes in brain function.

Don't forget the siblings: School-aged siblings of children presenting to mental health services show at-risk patterns of attachment

Family therapists understand that children presenting for treatment are often bearers of symptoms signalling relational problems within the family system. Rather than addressing the children's symptoms in isolation, family therapists typically take those relational problems as their starting point in therapy. This study used the School-aged Assessment of Attachment (SAA) to assess the self-protective (attachment) strategies of the siblings of children presenting for psychiatric evaluation and also of the siblings of control children drawn from the normative population. Siblings of children in the clinical group were much more likely than siblings of control children to use at-risk self-protective strategies and to have markers suggestive of unresolved loss or trauma. School-aged siblings were found to use a broad range of strategies, and the pattern of change from first born to later born involved either a reversal of strategy or a shift to a more complex strategy. The study highlights that siblings of children presenting to mental health services are significantly affected by family relational stress. A family systems approach to assessment, one that enquires about the wellbeing of all family members, will ensure that the emotional needs of siblings are also addressed during the therapy process.

The respiratory control of carbon dioxide in children and adolescents referred for treatment of psychogenic non-epileptic seizures

Psychogenic non-epileptic seizures (PNES) are a common problem in paediatric neurology and psychiatry that can best be understood as atypical responses to threat. Threats activate the body for action by mediating increases in arousal, respiration, and motor readiness. In previous studies, a range of cardiac, endocrine, brain-based, attention-bias, and behavioral measures have been used to demonstrate increases in arousal, vigilance, and motor readiness in patients with PNES. The current study uses respiratory measures to assess both the motor readiness of the respiratory system and the respiratory regulation of CO₂. Baseline respiratory rates during clinical assessment and arterial CO₂ levels during the hyperventilation component of routine video electroencephalogram were documented in 60 children and adolescents referred for treatment of PNES and in 50 controls. Patients showed elevated baseline respiratory rates [t(78) = 3.34, p = .001], with 36/52 (69%) of patients [vs. 11/28 (39%) controls] falling above the 75th percentile (χ² = 6.7343; df = 1; p = .009). Twenty-eight (47%) of patients [vs. 4/50 (8%) controls] showed a skewed hyperventilation-challenge profile—baseline PCO₂ <36 mmHg, a trough PCO₂ ≤ 20 mmHg, or a final PCO₂ <36 mmHg after 15 min of recovery—signaling difficulties with CO₂ regulation (χ² = 19.77; df = 1; p < .001). Children and adolescents with PNES present in a state of readiness-for-action characterized by high arousal coupled with activation of the respiratory motor system, increases in ventilation, and a hyperventilation-challenge profile shifted downward from homeostatic range. Breathing interventions that target arousal, decrease respiratory rate, and normalize ventilation and arterial CO₂ may help patients shift brain–body state and avert PNES episodes.

Cortical arousal in children and adolescents with functional neurological symptoms during the auditory oddball task

OBJECTIVE

Stress, pain, injury, and psychological trauma all induce arousal-mediated changes in brain network organization. The associated, high level of arousal may disrupt motor-sensory processing and result in aberrant patterns of motor function, including functional neurological symptoms. We used the auditory oddball paradigm to assess cortical arousal in children and adolescents with functional neurological symptom disorder.

METHOD

Electroencephalogram (EEG) data was collected in fifty-seven children and adolescents (41 girls; 16 boys, aged 8.5-18 years) with acute functional neurological symptoms and age- sex- matched controls during a conventional auditory oddball task. The high-resolution fragmentary decomposition technique was used to analyse the amplitude of event-related potentials (ERPs) to target tones at midline sites (Fz, Cz, and Pz).

RESULTS

Compared to age- and sex-matched controls, and across all three midline sites, children and adolescents with functional neurological symptoms showed increased amplitude of all ERP components (P50, N100, P200, N200, and P300) (t-value range 2.28-8.20; p value-range 0.023 to < 0.001) to the emotionally-neutral auditory stimulus.

CONCLUSIONS

Our findings add to a growing literature indicating that a baseline state of high arousal may be a precondition for generating functional neurological symptoms, a finding that helps explain why a range of psychological and physiological stressors can trigger functional neurological symptoms in some patients. Interventions that target cortical arousal may be central to the treatment of paediatric patients with functional neurological symptom disorder.

The body comes to family therapy: Treatment of a school-aged boy with hyperventilation-induced non-epileptic seizures

We present the case of a 10-year-old boy, Evan, where a knock to the head activated memories of past bullying, causing intense distress, activation of the body's stress-regulation systems and recurrent hospital presentations with hyperventilation-induced non-epileptic seizures. We describe the initial assessment session that enabled Evan and his family to understand the context for Evan's non-epileptic seizures, to engage with the therapeutic team and to collaborate in the implementation of a mind-body multimodal family-based intervention. Once the physical symptoms had been addressed therapeutically, we explored possible dangers within the family and school systems and we worked with Evan and his family to increase his ability to access comfort and protection from his parents. Our short hospital intervention highlighted the importance of ongoing therapeutic work with Evan and the family and laid the foundation stones for the next part of the family's therapeutic journey.