Imaging functional motor connectivity in hemiparetic children with perinatal stroke

Abstract

Perinatal stroke causes lifelong disability, particularly hemiparetic cerebral palsy. Arterial ischemic strokes (AIS) are large, cortical, and subcortical injuries acquired near birth due to acute occlusion of the middle cerebral artery. Periventricular venous infarctions (PVI) are smaller, subcortical strokes acquired prior to 34 weeks gestation involving injury to the periventricular white matter. Both stroke types can damage motor pathways, thus, we investigated resulting alterations in functional motor networks and probed function. We measured blood oxygen level dependent (BOLD) fluctuations at rest in 38 participants [10 arterial patients (age = 14.7 AE 4.1 years), 10 venous patients (age = 13.5 AE 3.7 years), and 18 typically developing controls (TDCs) (age = 15.3 AE 5.1 years)] and explored strength and laterality of functional connectivity in the motor network. Inclusion criteria included MRI-confirmed, unilateral perinatal stroke, symptomatic hemiparetic cerebral palsy, and 6-19 years old at time of imaging. Seed-based functional connectivity analyses measured temporal correlations in BOLD response over the whole brain using primary motor cortices as seeds. Laterality indices based on mean z-scores in lesioned and nonlesioned hemispheres explored laterality. In AIS patients, significant differences in both strength and laterality of motor network connections were observed compared with TDCs. In PVI patients, motor networks largely resembled those of healthy controls, albeit slightly weaker and asymmetric, despite subcortical damage and hemiparesis.Functional connectivity strengths were not related to motor outcome scores for either stroke group.This study serves as a foundation to better understand how resting-state fMRI can assess motor functional connectivity and potentially be applied to explore mechanisms of interventional therapies after perinatal stroke. K E Y W O R D Sperinatal stroke, functional connectivity, motor networks, resting-state fMRI, cerebral palsy, pediatric

Sensorimotor functional connectivity in unilateral cerebral palsy: influence of corticospinal tract wiring pattern and clinical correlates

“…However, the main predictor of UL motor deficits remains the underlying CST 525 wiring, as we have shown in a recent study (Simon-Martinez, Jaspers, et al, 2018), and is also in 526 agreement with previous literature (Staudt et al, 2004). The lack of a clear relation between 527 functional connectivity from M1 and UL motor deficits shown in our study are in agreement with the 528 recent findings of Saunders et al (Saunders et al, 2018). Despite the low correlations found in theirs 529 and our study, the potential value of functional connectivity in the uCP group may not be fully lost.…”

“…With our larger sample size, we can still observe that the functional 445 connectivity network of the whole uCP sample due to periventricular white matter lesions very well 446 resembles that of the TD cohort. Together with previous literature (Saunders et al, 2018), our results 447 suggest that the brain in individuals with a periventricular white matter lesion may have higher 448 plasticity potential to reorganize the motor network in such a way that it is not functionally altered. 449…”

“…The lack of differences in intrahemispheric connectivity within sensorimotor areas (in the 439 ROI-ROI approach) in the non-dominant hemisphere was unexpected, as we hypothesized that the 440 white matter lesion would reflect changes in this network. A recent study by Saunders et al has also 441 shown that the resting state motor network in children with such injuries highly resembles the motor 442 network of TD peers (Saunders et al, 2018). However, they found differences in the laterality index 443 between the two primary motor cortices, with grater asymmetry from the lesioned hemisphere, which 444 we could not replicate.…”

“…Other lesion types occurring around birth, i.e. ischemic arterial stroke, when grey matter is 450 predominantly damaged, seem to show a more lateralized motor network (Saunders et al, 2018), 451 potentially due to the grey matter loss. 452…”

Functional, neuroplastic and biomechanical changes induced by early Hand-Arm Bimanual Intensive Therapy Including Lower Extremities (e-HABIT-ILE) in pre-school children with unilateral cerebral palsy: study protocol of a randomized control trial

“…(iii) The topological properties of whole-brain networks will be analyzed using fMRI and graph theory and network analysis. The properties of the motor network will also be calculated [48,49].…”