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.