Longitudinal Functional Reorganization after Pediatric Stroke: A Descriptive Case Study

Case Study: Compared with adults, data on reorganizational patterns in resting state brain networks of children who suffered an arterial ischemic stroke (AIS) is rare. We, therefore, examined changes in resting state activity of a 7-year-old boy 1 and 4 months after an acute right-sided periventricular AIS.

Methods: One boy who recently suffered with an acute AIS was examined. Magnetic resonance (MR) images were acquired using a 3T scanner. High-resolution T1-weighted MR structural images were recorded using a magnetization prepared rapid gradient echo 3D sequence and functional imaging was performed using a multiband echo planar imaging sequence. Conn toolbox 141 was used to descriptively compare resting state activity in different regions of interest.

Results: 1 month poststroke, a clear activity shift to the contralesional hemisphere resulting in bilateral activation is visible in several different regions, such as, the primary motor cortex, the inferior frontal cortex pars triangularis, the somatosensory cortex, and the primary visual cortex (see Fig. 1). In those areas, interhemispheric balance is retained 4 months' poststroke (see Fig. 2).

Conclusions: The results suggest that in the child's brain, dynamic reorganization processes in resting state activity over time might happen. As the hemispheric shift to the contralesional side, 1 month poststroke and the rebalance 4-month poststroke are visible in different brain areas, we assume that functional reorganization patterns might be of global character. The present results are based on one single case only, but may serve as an important indicator for dynamic changes in the pediatric brain connectivity after stroke. Therefore, further analyses including more children are necessary.

Keywords: pediatric arterial ischemic stroke, functional reorganization, resting-state activity.