Left hemisphere structural connectivity abnormality in pediatric hydrocephalus patients following surgery

Abstract

Neuroimaging research in surgically treated pediatric hydrocephalus patients remains challenging due to the artifact caused by programmable shunt. Our previous study has demonstrated significant alterations in the whole brain white matter structural connectivity based on diffusion tensor imaging (DTI) and graph theoretical analysis in children with hydrocephalus prior to surgery or in surgically treated children without programmable shunts. This study seeks to investigate the impact of brain injury on the topological features in the left hemisphere, contratelateral to the shunt placement, which will avoid the influence of shunt artifacts and makes further group comparisons feasible for children with programmable shunt valves. Three groups of children (34 in the control group, 12 in the 3-month post-surgery group, and 24 in the 12-month post-surgery group, age between 1 and 18 years) were included in the study. The structural connectivity data processing and analysis were performed based on DTI and graph theoretical analysis. Specific procedures were revised to include only left brain imaging data in normalization, parcellation, and fiber counting from DTI tractography. Our results showed that, when compared to controls, children with hydrocephalus in both the 3-month and 12-month post-surgery groups had significantly lower normalized clustering coefficient, lower small-worldness, and higher global efficiency (all p < 0.05, corrected). At a regional level, both patient groups showed significant alteration in one or more regional connectivity measures in a series of brain regions in the left hemisphere (8 and 10 regions in the 3-month post-surgery and the 12-month post-surgery group, respectively, all p < 0.05, corrected). No significant correlation was found between any of the global or regional measures and the contemporaneous neuropsychological outcomes [the General Adaptive Composite (GAC) from the Adaptive Behavior Assessment System, Second Edition (ABAS-II)]. However, one global network measure (global efficiency) and two regional network measures in the insula (local efficiency and between centrality) tested at 3-month post-surgery were found to correlate with GAC score tested at 12-month post-surgery with statistical significance (all p < 0.05, corrected). Our data showed that the structural connectivity analysis based on DTI and graph theory was sensitive in detecting both global and regional network abnormality when the analysis was conducted in the left hemisphere only. This approach provides a new avenue enabling the application of advanced neuroimaging analysis methods in quantifying brain damage in children with hydrocephalus surgically treated with programmable shunts.

A Review of Data Analysis for Early-Childhood Period: Taxonomy, Motivations, Challenges, Recommendation, and Methodological Aspects

“…The last screening technique of the brain development is Magnetic resonance imaging (MRI). The MRI technique was used mostly in the brain development with a majority of studies [8], [10], [18], [35], [36], [54], [55] and across different areas. Two studies were involved with the growth trajectories of different areas of the brain similar to [18] and [36].…”

“…Two more studies were related to age changes in children and examined whether these changes were functional [8] or related to limbic structures and symptomatology [54]. The last few articles discussed various topics, such as brain left hemisphere [55], white matter maturation [35] and neural connectivity patterns [10]. These studies were categorized on the basis of the screening technique.…”

“…Data is the most important aspect in any study and it is the most significant effector that controls the analysis, findings and all the study's elements. However, when dealing with early childhood studies, some notable data issues occur in many areas of literature, such as missing data [21], [66], [138], [152], [176], [199], [212], reliance on administrative data [114], [137], [138] and the huge lack of longitudinal data and studies [1], [3], [17], [28], [31], [37], [41], [48], [55], [71], [102], [109], [114], [123], [124], [160], [162], [177], [178], [184], [192]- [194], [206], [212], [213], [222], [228], [231], [233]. Other studies shed light on other issues related to data, which include structure [1], accuracy [110], incompletion [100] and scarcity [65], [116].…”

“…This challenge discusses major issues related to the samples and population of previous studies; several issues were identified with respect to early childhood studies, which include a small sample size, as pointed out in references [5], [10]- [12], [14], [23], [40], [53], [55], [61], [66], [81], [87], [90], [97], [111], [112], [116], [119], [129], [135], [138], [141]- [143], [146], [149], [152], [159], [164], [173], [176], [179], [181], [187], [198], [199], [206], [207], [211], [212], [219], [224]- [226], [233], [236].…”

White Matter Injury in Early Brain Injury after Subarachnoid Hemorrhage

“…Though it was thought to be passive tissue, white matter actually affects multiple brain functions. The role of white matter in the central nervous system includes supporting and connecting different parts of brain gray matter together, modulating the distribution of action potentials, acting as a relay and coordinating essential neuronal communications 23 , as well as information conveyance among the network of efferent and afferent axonal fibers between the brain and spine 24,25 . In the brain, white matter is mainly located in the deep brain, such as periventricular area and subcortical area, where the blood supply is usually poor 26,27 .…”