title: Cortical arousal in children and adolescents with functional neurological symptoms during the auditory oddball task.
abstract: 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.
  
  
  
  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).
  
  
  
  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.
  
  
  
  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.
authors.affiliation: The Children's Hospital at Westmead, Brain Dynamics Centre at Westmead Institute for Medical Research, Discipline of Psychiatry and Discipline of Child and Adolescent Health at University of Sydney Medical School, NSW, Australia.
authors.forename: Kasia
authors.initials: K
authors.lastname: Kozlowska
authors.affiliation: Western Clinical School, Discipline of Psychiatry, University of Sydney Medical School, NSW, Australia.
authors.forename: Dmitriy
authors.initials: D
authors.lastname: Melkonian
authors.affiliation: Brain Resource, NSW, Australia.
authors.forename: Chris J
authors.initials: CJ
authors.lastname: Spooner
authors.affiliation: Department of Psychiatry, Harvard Medical School, McLean Hospital, Belmont, MA, USA; School of Public Health, Sydney University Medical School, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Scher
authors.affiliation: University of Sydney Medical School, NSW, Australia.
authors.forename: Russell
authors.initials: R
authors.lastname: Meares
mesh_terms: D000293:Adolescent; D001143:Arousal / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D002648:Child; D004569:Electroencephalography; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008016:Life Change Events; D008297:Male; D009422:Nervous System Diseases / Q000209:etiology / Q000503:physiopathology*; D017397:Prefrontal Cortex / Q000503:physiopathology*
keywords: Auditory oddball; Conversion disorder; Dissociation; EEG, electroencephalogram; ERP; ERP, event-related potential; Functional neurological symptoms; GMP, generic mass potential; PFC, Prefrontal cortex; dlPFC, Dorsolateral prefrontal cortex