Cognitive and behavioral development up to 4 years after early right frontal lobe lesion

The neuropsychological consequences of hemorrhage and surgical repair of a deep right frontal arteriovenous malformation in a 7-year-old boy are described. The lesion involved the right dorsolateral prefrontal cortex, subjacent white matter, and small portions of premotor cortex and the anterior insula. Effects in the early recovery phase included left hemispatial neglect with constructional apraxia, distractibility, impulsive responses, impaired visual memory, difficulty in completing multistep activities, and emotional liability. Speech, language, and general cognitive measures remained within the normal range. The patient returned to school 21/2 months later and has continued in regular classes. Extensive evaluation at 4 years after onset indicated improvement but specific impairments in executive functions, including attentional control, visuospatial working memory, cognitive flexibility, and organizational strategies for learning despite superior intelligence level. Behaviorally, he developed an acquired form of attention deficit disorder as well as mild personality and social impairments. The findings support an important role for the right dorsolateral prefrontal region in diverse aspects of executive functions as well as personality and social development in childhood. Although cerebral plasticity and other recovery processes may account for the improvement observed in this patient, the remaining impairments may be long-term effects of this lesion site. Ongoing studies should reveal either continuing improvement or evolving deficits as cognitive and social demands increase throughout adolescence.