Overflow movements and white matter abnormalities in ADHD.
Multiple motor abnormalities have been identified in some children with Attention Deficit/Hyperactivity Disorder (ADHD). These include persistence of overflow movements, impaired timing of motor responses and deficits in fine motor abilities. Motor overflow is defined as co-movement of body parts not specifically needed to efficiently complete a task. The presence of age-inappropriate overflow may reflect immaturity of the cortical systems involved in automatic motor inhibition. Theories on overflow movements consistently implicate impairments in white matter (WM) tracts, including the corpus callosum. WM connections might be altered selectively in brain networks and thus influence motor behaviours. We reviewed the scientific contributions on overflow movements and WM abnormalities in ADHD. They suggest that WM abnormalities in motor/premotor circuits, which are important for motor response inhibition, might be responsible for overflow movements in patients with ADHD.
D'Agati
Elisa
E
Unit of Child Neurology and Psychiatry, Department of Neuroscience, University of Rome Tor Vergata, Italy. elisadagati@gmail.com
Casarelli
Livia
L
Pitzianti
Maria Bernarda
MB
Pasini
Augusto
A
D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications* / Q000473:pathology*; D006801:Humans; D009068:Movement / Q000502:physiology; D009069:Movement Disorders / Q000150:complications* / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology*