Research On Cortical Neural Network Of Subcortical Ischemic Stroke, Brain Development And Aging

Stroke has remained as a leading cause of death and neurological disability worldwide in the past decades. Previous structural and functional studies reported little information regarding cortical neural network after stroke.Using the causality measure based on multi-channel electroencephalograph (EEG), i.e. partial directed coherence (PDC) in this paper, we investigated the different network patterns involved in pre-motor and parietal areas (F3, F4, C3, C4, P3 and P4) in three groups of patients who suffered unilateral or bilateral hemispheric stroke in basal ganglia with extension into corona radiate.Compared with the results in the control group, stroke patients showed: 1) more vulnerable long-distance intra- and inter-hemispheric interactions due to the ischemic injury; 2) strengthened short-distance interactions between the central areas in the intact hemisphere with the injured counterpart, which implied a functional compensation after unilateral stroke; 3) more suppression of cortical connections after bilateral hemispheric stroke than those with unilateral stroke. Causal interdependence by PDC analysis provides a new insight of cortical functional network following strokeIn addition, the application of the PDC method analysis in brain development and ageing was also studied in this paper. How the cortical neural network develops and then degenerates was examined with three age groups.We investigated the different neural networks involved in the whole cortex as well as the anterior and posterior areas in three age groups, i.e. children (0-10years), mid-aged adults (26-38years) and the elderly (56-80years). The following findings were concluded by comparing the cortical causal connective networks in different groups: 1) The right hemisphere develops cortical neural connective network earlier than its left counterpart in the development stage; 2) The anterior cortex is demonstrated to undergo far more extensive changes of neural networks, especially at C3 and F3, compared with the posterior area during brain development and ageing; 3) The asymmetry of the interactive cortical neural networks declines during ageing with more loss of connectivity in the left frontal and central areas.Above all, we can conclude causal interdependence by PDC analysis effectively provides new insights into the cortical functional connective networks during stroke, brain development and ageing.