Magnetic resonance imaging of brain contusion

Technical report: minor head injury in children

Minor head trauma affecting children is a common reason for medical consultation and evaluation. In order to provide evidence on which to base a clinical practice guideline for the American Academy of Pediatrics, we undertook a systematic review of the literature on minor head trauma in children.

METHODS

Medline and Health databases were searched for articles published between 1966 and 1993 on head trauma or head injury, limited to infants, children, and adolescents. Abstracts were reviewed for relevance to mild head trauma consistent with the index case defined by the AAP subcommittee. Relevant articles were identified, reviewed, and abstracted. Additional citations were identified by review of references and expert suggestions. Unpublished data were also identified through contact with authors highlighting child-specific information. Abstracted data were summarized in evidence tables. The process was repeated in 1998, updating the review for articles published between 1993 and 1997.

RESULTS

A total of 108 articles were abstracted from 1033 abstracts and articles identified through the various search strategies. Variation in definitions precluded any pooling of data from different studies. Prevalence of intracranial injury in children with mild head trauma varied from 0% to 7%. Children with no clinical risk characteristics are at lower risk than are children with such characteristics; the magnitude of increased risk was inconsistent across studies. Computed tomography scan is most sensitive and specific for detection of intracranial abnormalities; sensitivity and specificity of skull radiographs ranged from 21% to 100% and 53% to 97%, respectively. No high quality studies tested alternative strategies for management of such children. Outcome studies are inconclusive as to the impact of minor head trauma on long-term cognitive function.

CONCLUSIONS

The literature on mild head trauma does not provide a sufficient scientific basis for evidence-based recommendations about most of the key issues in clinical management. More consistent definitions and multisite assessments are needed to clarify this field.

Late MRI after head injury in children: relationship to clinical features and outcome

To characterize the brain pathology in relation to long-term outcome after pediatric head injury, 55 children were studied by magnetic resonance imaging (MRI) at least 3 months after sustaining moderate to severe closed head injury (CHI). Thirty-nine of the patients had abnormal signal intensity consistent with residual brain lesions, including 28 children with lesions involving the frontal lobes. The clinical features of children with frontal lesions, extrafrontal lesions, and diffuse injury were compared. The analysis disclosed that children with frontal lobe lesions were more frequently disabled than children who sustained diffuse injury. Our MRI findings indicate that residual brain lesions are more common after moderate to severe CHI in children than previously thought and that the frontal lobes are most frequently involved. Further investigation is indicated to elucidate whether distinctive cognitive and behavioral sequelae are associated with frontal lobe lesions in children.