Functional connectivity for somatosensory and motor cortex in spastic diplegia

Abstract

Functional connectivity (fcMRI) was analyzed in individuals with spastic diplegia and age-matched controls. Pearson correlations (r-values) were computed between resting state spontaneous activity in selected seed regions (sROI) and each voxel throughout the brain. Seed ROI were centered on foci activated by tactile stimulation of the second fingertip in somatosensory and parietal dorsal attention regions. The group with diplegia showed significantly expanded networks for the somatomotor but not dorsal attention areas. These expanded networks overran nearly all topological representations in somatosensory and motor areas despite a sROI in a fingertip focus. A possible underlying cause for altered fcMRI in the group with dipegia, and generally sensorimotor deficits in spastic diplegia, is that prenatal third trimester white-matter injury leads to localized damage to subplate neurons. We hypothesize that intracortical connections become dominant in spastic diplegia through successful competition with diminished or absent thalamocortical inputs. Similar to the effects of subplate ablations on ocular dominance columns (Kanold and Shatz, Neuron 2006;51:627-638), a spike timing-dependent plasticity model is proposed to explain a shift towards intracortical inputs.

Resting-state networks in the macaque at 7T

“…6a of Beckmann et al, 2005) networks respectively. Further, RSNs G (cingulo-insular), J (postcentral), and K (hippocampal) though not consistently reported in studies utilizing ICA, have homologous networks that can be found when comparing task-based or seed-region analysis of human fMRI data (Kringelbach, 2005;Blatow et al, 2007;Burton et al, 2009;Vincent et al, 2006). Two recent studies have examined resting-state connectivity with hypotheses derived from experimental anterograde tracer studies of the macaque monkey (Margulies et al, 2009;Kelly et al, 2010).…”

Anatomical characterization of athetotic and spastic cerebral palsy using an atlas‐based analysis

“…Consequently, reports about the whole-brain anatomical analyses of CP patients are scarce. For children with spastic CP, several studies using VBA and functional connectivity indicated that there was a possibility that descending motor tract injury and disruptions in the somatosensory regions might lead to developmental delays, abnormal sensory feedback for motor coordination, and deficits in motor function (18,28), although the mechanism of motor impairment and the functional predictors at an early age are still debatable. With regard to children with athetotic CP, previous MRI studies were mostly based on visual assessment or manual ROI approaches (6-10, 16).…”

Evaluation of cortical plasticity in children with cerebral palsy undergoing constraint-induced movement therapy based on functional near-infrared spectroscopy

“…The increased connectivity between hemispheres is presumed to be a compensatory reaction to the loss of connections with white matter after brain injury. 61 CIMT has been used to enforce increased use of the affected hand and reduce overreliance on the unaffected hemisphere, 8 which is accompanied by partial normalization of brain activation patterns. 16,18 In this work, fNIRS was used to map the plastic changes that occurred in the sensorimotor cortex of six children with CP immediately after and 6 months after 2 weeks of CIMT.…”