Retinal hemorrhage and brain injury patterns on diffusion-weighted magnetic resonance imaging in children with head trauma

PURPOSE To evaluate associations between retinal hemorrhage severity and hypoxic-ischemic brain injury (HIT) patterns by diffusion-weighted magnetic resonance imaging (DIV-MRI) in young children with head trauma. METHODS DW-MRI images of a consecutive cohort study of children under age 3 years with inflicted or accidental head trauma who had eye examinations were analyzed by two independent masked examiners for type, severity, and location of primary lesions attributable to trauma, HIT secondary to trauma, and mixed injury patterns. Retinal hemorrhage was graded retrospectively on a scale from 1 (none) to 5 (severe). RESULTS Retinal hemorrhage score was 3-5 in 6 of 7 patients with predominantly post-traumatic HII pattern and 4 of 32 who had traumatic injury without HIT (P < 0.001) on DW-MRI imaging. Severe retinal hemorrhage was observed in absence of HIT but only in inflicted injury. Retinal hemorrhage severity was correlated with HIT severity (rho = 0.53, P < 0.001) but not traumatic injury severity (rho = -0.10, P = 0.50). HII severity was associated with retinal hemorrhage score 3-5 (P = 0.01), but traumatic injury severity was not (P = 0.37). CONCLUSIONS During inflicted head injury, a distinct type of trauma occurs causing more global brain injury with HIT and more severe retinal hemorrhages. HIT is not a necessary factor for severe retinal hemorrhage to develop from inflicted trauma.