The consequences of early frontal lobe damage, restricted to the polar and mesial portion of the left prefrontal cortex and deep white matter, on higher cognitive and psychologic development are reported in a 33-year-old woman who sustained injury at 7 years of age and was evaluated at the Division of Behavioral Neurology and Cognitive Neuroscience, University of Iowa College of Medicine, Iowa City. The birth and milestones of development were normal, and academic achievement was average before she sustained a spontaneous intraparenchymal cerebral hemorrhage at 7 years. Her neurological exam was normal and generalized tonic clonic seizures were controlled with medication. MRI revealed the lesion in the left prefrontal cortex and deep white matter, and cerebral blood flow studies were abnormal in left and right frontal regions. Defects in higher cognition were noted especially in self regulation of emotion and affect and in social behavior. These were of delayed onset and were followed by a period of progression and finally an arrest of development in adolescence. The progressive impairment resulted from a discrepancy between the demands of adolescent development and the altered maturation of frontal lobe neural and cognitive systems. The patient failed to acquire the executive and self regulatory processes associated with frontal lobe function. [1]