The psychobiology of childhood stress

Contingent negative variation in children with orthostatic dysregulation

BACKGROUND

Children with orthostatic dysregulation (OD) appear to have hypodynamia, as well as the symptoms described in the OD criteira. Hypodynamia, which is greatly influenced by motivation, volition and concentration, is unexceptionally recognized in their everyday life. It has been suggested that the symptoms and hypodynamia aggravate considerably the quality of life (QOL) of children with OD. The purpose of this study was to distinguish the characteristics of contingent negative variation (CNV) and post imperative negative variation, which may reflect the level of attention and motivation in children with OD.

METHODS

Twelve patients with OD aged 10-15 years and 23 age-matched healthy children were included. The CNV was recorded from Fz, Cz and Pz linked to earlobes during 30 trials consisting of a warning stimulus and an imperative stimulus with an interstimulus interval (ISI) of 2 s and an intertrial interval (ITI) of 10 s. The imperative stimulus of each trial required a button to be pressed.

RESULTS

The untreated children with OD did not have a significantly smaller CNV amplitude than healthy children. Children with OD treated with midodrine and autonomic training had a significantly larger CNV amplitude than the untreated children, in the area of early, late and total CNV at the three sites.

CONCLUSION

The present study confirms that children with OD have diminished motivation and deterioration of concentration, which cause hypodynamia in everyday life. Treatment for OD improves the symptoms, diminished motivation and deterioration of concentration, consequently restoring dynamia. Treatment for OD should be recommended to ameliorate QOL of children with OD.

Evolving the biobehavioral family model: the fit of attachment

The 1993 Biobehavioral Family model (BBFM) posits that family relational patterns and biobehavioral reactivity interact so as to influence the physical and psychological health of the children. The revised 1999 BBFM incorporates parent-child attachment as a pivotal construct. The current study tests the 1999 BBFM by predicting, in asthmatic children, that child perception of parental relationship quality, triangulation of child in marital conflict, and parent-child security of relatedness will be associated with hopelessness and vagal activation (one mechanism of airway compromise in asthma). In this study, 22 children with asthma (11 males/11 females, aged 8 to 16), watched, alone, an emotionally challenging movie, then engaged in family discussion tasks (problem solving, loss, conflict, cohesion) and completed the Children's Perception of Interparental Scale, the Relatedness Questionnaire, The Multidimensional Scale of Anxiety in Children, and the Hopelessness Scale for Children. Heart rate variability, measured at baseline and throughout the movie and family tasks, was used to compute respiratory sinus arrhythmia (RSA)--an inferential measure of vagal activation. The child's perception of parental conflict showed trends of association with triangulation and insecure father-child relatedness. Triangulation and hopelessness also were associated with insecure father-child relatedness, all of which were associated with vagal activation. Insecure mother-child relatedness was correlated only with hopelessness. Anxiety was not related to any variables. These findings lend support to the 1999 BBFM, and suggest a key role for parent-child attachment.