Clinical significance of scalp abnormalities in asymptomatic head-injured infants

Objectives: 1) To identify clinical features indicating a high risk of skul l fracture (SF) and associated intracranial injury (ICI) in asymptomatic he ad-injured infants, 2) To develop a clinical decision rule to determine whi ch asymptomatic head-injured infants require head imaging. Methods: We performed a prospective cohort study of all asymptomatic head-i njured infants 0-24 months of age presenting to the emergency department of an urban children's hospital. Infants were considered asymptomatic if they had no clinical signs of brain injury, or of basilar or depressed SF, Amon g subjects who had head imaging, we assessed the utility of age, scalp hema toma size, and scalp hematoma location for predicting SF and ICI. Results: Of 422 study patients, 45 (11%) were diagnosed with SF and 13 (3%) with ICI, In the 172 subjects who had head imaging, there was a stepwise r elationship between hematoma size and likelihood of SF. Parietal and tempor al hematomas were highly associated with SF; frontal hematomas were not. Th ere was a trend toward higher rates of SF in younger patients, Both large s calp hematoma and parietal hematoma were associated with ICI. Using these data, we developed a clinical decision rule to determine which asymptomatic infants need head imaging. In our study population, this rule has a sensitivity of 0.98 and specificity of 0.49 for SF, and it detects al l 13 cases of ICI, The clinical rule calls for imaging in 146/422 (35%) stu dy subjects. Conclusions: Among asymptomatic head-injured infants, the risk of SF and as sociated ICI is correlated with scalp hematoma size, hematoma location, and weakly with patient age. We propose a clinical decision rule that could id entify most cases of SF and ICI while not requiring head imaging for most p atients. This decision rule should be validated in other study populations.