Aberrant prefrontal cortical-striatal functional connectivity in children with primary complex motor stereotypies.

Motor stereotypies are rhythmic, repetitive, prolonged, predictable, and purposeless movements that stop with distraction. Although once believed to occur only in children with neurodevelopmental disorders such as autism, the presence and persistence of complex motor stereotypies (CMS) in otherwise typically developing children (primary CMS) has been well-established. Little, however, is known about the underlying pathophysiology of these unwanted actions. The aim of the present study was to use resting-state functional magnetic resonance imaging to evaluate functional connectivity within frontal-striatal circuits that are essential for goal-directed and habitual activity in children with primary complex motor stereotypies. Functional connectivity between prefrontal cortical and striatal regions, considered essential for developing goal-directed behaviors, was reduced in children with primary CMS compared to their typically developing peers. In contrast, functional connectivity between motor/premotor and striatal regions, critical for developing and regulating habitual behaviors, did not differ between groups. This documented alteration of prefrontal to striatal connectivity could provide the underlying mechanism for the presence and persistence of complex motor stereotypies in otherwise developmentally normal children.

Neuroimaging of fibromyalgia.

Functional MRI blood oxygenation level dependent activation studies on patients who have fibromyalgia have demonstrated augmented sensitivity to painful pressure and the association of this augmentation with variables such as depression and catastrophizing and have also been used to evaluate the symptoms of cognitive dysfunction. Using a wide array of techniques, these studies have found differences in opioid receptor binding, in the concentration of metabolites associated with neural processing in pain-related regions, in functional brain networks, and in regional brain volume and white matter tracks. A common theme of all of these methods is that they provide information that may be pertinent to the otherwise unobservable and poorly treated symptoms of persistent widespread chronic pain.