Twenty-five children with single focal stroke lesions, and without evidence of prestroke ADHD, were studied clinically for ADHD symptomatology and by brain magnetic resonance imaging at University of California, San Diego, CA. Fifteen (60%) had either ADHD or ADHD/Traits; 11 with ADHD (5 inattentive type), 3 with ADHD/Traits (2 with hyperactivity/impulsivity symptoms). In 13 subjects with stroke lesions <10 cm3, 6/7 with and only 2/6 without putamen lesions had ADHD. Traits (p=0.1). One half of those with (4/8) and none of 5 without ADHD/Traits had overlapping lesions involving the posterior ventral putamen (p=0.1). Lesions within the ventral putamen increased the risk of ADHD. Traits. 
COMMENT. A striatal lesion caused by stroke and involving the posterior ventral putamen may underly symptoms of ADHD, in the absence of damage to the caudate nucleus, an area often implicated in previous imaging studies. The dopamine-rich ventral putamen is part of the limbic striatum or cortico-striato-thalamocortical loop, Pathology and dysfunction in this loop, or a “disinhibition syndrome,” may be a factor in the cause of the ADHD syndrome. These authors have also demonstrated a correlation between childhood stroke and psychiatric disorders in childhood. 
Punctate brain MRI lesions in preterm infants do not appear to correlate with delay in neurodevelopment in a study at Leeds General Infirmary, UK . Punctate lesions occur in 30% of preterm and 5% of term infants. Lesions are usually linear and located in the centrum semiovale.