Patterns of cerebral parenchymal injury and their relationship to outcome morbidity are evaluated in this retrospective study of 14 children with confirmed nonaccidental head injury (NAHI). The mean age at time of injury was 12 months 6 days, mean Children's Coma Score was 5.36, and mean postinjury follow-up was 17 months 12 days. All patients had acute subdural hematoma (interhemispheric or convexity) on initial CT imaging. Two major groups of children were identified from initial CT scans; those with diffuse cerebral hypoattenuation (n = 7) and those with focal cerebral hypoattenuation (n = 7). The two groups differed significantly by age (diffuse group, mean age 5 months 9 days +/- 36 days; focal group, mean age 19 months 3 days +/- 6 months 9 days; P < 0.01) and ultimate type and extent of parenchymal damage. Outcome was generally poor in both groups (mean Children's Outcome Score of III/IV). Cerebral infarction developed in all survivors. Most common were hemispheric necrosis after hemispheric swelling subjacent to an ipsilateral convexity acute subdural hematoma (n = 5); distribution of the posterior cerebral artery (n = 4) or callosomarginal branch of the anterior cerebral artery (n = 4); and borderzone infarctions (n = 4). Of 14 children, 11 (79%) had early posttraumatic seizures (EPTS). Clinical progression of symptoms was confirmed in nine patients (mean Childrens Coma Score was 4.0 +/- 0.33). None had a lucid interval. This is the first study using strict inclusion criteria that documents the range of infarction patterns and potential age-dependent differences in postinjury response cascades after nonaccidental head injury.