Cerebral hemispheric low-grade glial tumors in children: preoperative anatomic assessment with MRI and DTI

Structural networking of the developing brain: from maturation to neurosurgical implications

Modern neuroscience agrees that neurological processing emerges from the multimodal interaction among multiple cortical and subcortical neuronal hubs, connected at short and long distance by white matter, to form a largely integrated and dynamic network, called the brain "connectome." The final architecture of these circuits results from a complex, continuous, and highly protracted development process of several axonal pathways that constitute the anatomical substrate of neuronal interactions. Awareness of the network organization of the central nervous system is crucial not only to understand the basis of children's neurological development, but also it may be of special interest to improve the quality of neurosurgical treatments of many pediatric diseases. Although there are a flourishing number of neuroimaging studies of the connectome, a comprehensive vision linking this research to neurosurgical practice is still lacking in the current pediatric literature. The goal of this review is to contribute to bridging this gap. In the first part, we summarize the main current knowledge concerning brain network maturation and its involvement in different aspects of normal neurocognitive development as well as in the pathophysiology of specific diseases. The final section is devoted to identifying possible implications of this knowledge in the neurosurgical field, especially in epilepsy and tumor surgery, and to discuss promising perspectives for future investigations.

Dysplasia and overgrowth: magnetic resonance imaging of pediatric brain abnormalities secondary to alterations in the mechanistic target of rapamycin pathway

The current classification of malformations of cortical development is based on the type of disrupted embryological process (cell proliferation, migration, or cortical organization/post-migrational development) and the resulting morphological anomalous pattern of findings. An ideal classification would include knowledge of biological pathways. It has recently been demonstrated that alterations affecting the mechanistic target of rapamycin (mTOR) signaling pathway result in diverse abnormalities such as dysplastic megalencephaly, hemimegalencephaly, ganglioglioma, dysplastic cerebellar gangliocytoma, focal cortical dysplasia type IIb, and brain lesions associated with tuberous sclerosis. We review the neuroimaging findings in brain abnormalities related to alterations in the mTOR pathway, following the emerging trend from morphology towards genetics in the classification of malformations of cortical development. This approach improves the understanding of anomalous brain development and allows precise diagnosis and potentially targeted therapies that may regulate mTOR pathway function.