The manual dexterity subtests of the Movement Assessment Battery for Children, and handwriting and computerized graphomotor tasks were used to investigate motor skills of a group of 12 children (11 males, 1 female; mean age 9 years 7 months) with attention deficit hyperactivity disorder (ADHD) and developmental coordination disorder (DCD) and 12 controls at University Medical Centre Groningen, the Netherlands. ADHD-DCD children had severely impaired fine motor abilities, they made more errors and were slower in completing manual dexterity tests (p=0.001), their handwriting was poorer (p=0.002), and on a flower trail graphomotor task, they drew more rapidly and fluently but were less accurate than controls (p=0.002). When treated with methylphenidate, manual dexterity was improved (p=0.003), handwriting quality improved (p=0.042), and lines on the graphomotor task were less fluent (p=0.028) but more accurate (p=0.01). It is estimated that 50% of children with ADHD have comorbid DCD. 
COMMENT. The prevalence of incoordination and other “subtle” neurologic abnormalities in hyperactive children with attention deficits (ADHD) was recognized by the NINDB Task force in 1966, when the term “minimal brain dysfunction (MBD)” was coined for the syndrome. Subtle abnormal neurological signs included dysgraphia, dyspraxias (clumsiness), and incoordination, and are now described under DCD. In the DSM criteria for the diagnosis of ADHD, reference to impaired motor performance, clumsiness, and incoordination has been omitted. The early concept of an organic or neurobiologic syndrome, as embraced by many neurologists, has been rejected in favor of a symptom diagnosis. In Scandinavia, the syndrome of DAMP emphasizes the association of neurological signs of motor dysfunction, perceptual dysfunction, and attention deficits. The overlap of ADHD and DAMP, the higher prevalence of DAMP among children with neurodevelopmental disorders (Ped Neur Briefs Nov 1996) , and the response of subtle signs of neurologic dysfunction to methylphenidate, are findings that should favor the inclusion of signs of neurologic and perceptual dysfunction in the criteria for diagnosis of ADHD. The term “attention deficit hyperactivity & coordination disorder (ADH&CD)” would seem more appropriate. This modification of diagnostic criteria would allow a more objective diagnosis of the syndrome, earlier recognition and treatment, and more effective remediation of the associated motor incoordination and perceptual deficits. Neurologists should be more involved with the ADHD diagnostic criteria and their management. Children with ADHD complicated by incoordination and other symptoms of DCD are at increased risk for learning and especially language and reading problems. 
The relation of brain myelination to the development of language in 100 infants and toddlers is investigated using three dimensional MRI at the University of Barcelona, Spain . The volume of myelinated white matter was measured in language-related temporal and frontal regions and in the central sensorimotor region. A spurt in vocabulary coincided with the end of a rapid myelination stage in language areas at 18 to 24 months.