Brain lesions in pediatric abusive head trauma: prevalence, pathophysiology, patterns, and a classification system.

Objectives: A deeper understanding of extensive brain lesions (EBL) in pediatric abusive head trauma (AHT) could possibly help differentiate AHT from other forms of trauma. Therefore, the aims of the study were (i) to investigate the prevalence and features of AHT-associated EBL in neuroimaging and (ii) to develop a useful classification system.

Materials And Methods: This retrospective multicenter study analyzed cranial CT and/or MRI of medico-legally well-documented AHT cases diagnosed with "shaken baby syndrome" from a 10-year study period with respect to lesions in cerebrum, cerebellum, and brain stem. For the development of a classification system, EBLs were grouped into distinct lesion patterns based on laterality, symmetry, distribution, and shape.

Results: A total of 61 AHT cases were included. Comparison between "confession cases" (n = 15) and "non-confession cases" (n = 46) did not show any statistically significant difference regarding all parameters analysed. EBL were found in ~ 1/3 of the cases (n = 20). Brain stem lesions were only rarely observed (n = 2). Nine different and partly new patterns of EBL occurring in AHT by shaking are described. Pattern analysis revealed that most lesions can be caused by hypoxic-ischemic injury, but evidence is provided that additional pathomechanisms, such as hypoglycemia and the "second impact syndrome", may be causative or a component.

Conclusions: Brain lesions in AHT by shaking form typical patterns that can be categorized. Considering the rare observation of brain stem lesions, the widespread hypothesis of primary brain stem lesions leading to initial respiratory insufficiency in AHT by shaking should be questioned.

Key Points: Question Current data on extensive brain lesion patterns in abusive head trauma are insufficient with regard to nomenclature, pathophysiology, and a classification system. Findings Nine different patterns of extensive brain lesions were found in abusive head trauma by shaking, which indicates different pathomechanisms and may help diagnose child abuse. Clinical relevance Consideration of the identified lesion patterns provides new insights into underlying pathomechanisms and supports the clinical diagnosis of abusive head trauma.