Advances in Stroke Prevention in 2018

Longitudinal prediction of motor dysfunction after stroke: a disconnectome study

Motricity is the most commonly affected ability after a stroke. While many clinical studies attempt to predict motor symptoms at different chronic time points after a stroke, longitudinal acute-to-chronic studies remain scarce. Taking advantage of recent advances in mapping brain disconnections, we predict motor outcomes in 62 patients assessed longitudinally two weeks, three months, and one year after their stroke. Results indicate that brain disconnection patterns accurately predict motor impairments. However, disconnection patterns leading to impairment differ between the three-time points and between left and right motor impairments. These results were cross-validated using resampling techniques. In sum, we demonstrated that while some neuroplasticity mechanisms exist changing the structure-function relationship, disconnection patterns prevail when predicting motor impairment at different time points after stroke.

Modes of Calcium Regulation in Ischemic Neuron

Calcium (Ca²⁺) dysregulation is a major catalytic event. Ca²⁺ dysregulation leads to neuronal cell death and brain damage result in cerebral ischemia. Neurons are unable in maintaining calcium homeostasis. Ca²⁺ homeostasis imbalance results in increased calcium influx and impaired calcium extrusion across the plasma membrane. Ca²⁺ dysregulation is mediated by different cellular and biochemical mechanism, which leads to neuronal loss resulting stroke/cerebral ischemia. A better understanding of the Ca²⁺ dysregulation might help in the development of new treatments in order to reduce ischemic brain injury. An optimal concentration of Ca²⁺ does not lead to neurotoxicity in the ischemic neuron. Intracellular Ca²⁺ act as a trigger for acute neurotoxicity and this cause induction of long-lasting processes leading to necrotic and/or apoptotic post-ischemic delayed neuronal death or of compensatory, neuroprotective mechanisms has increased considerably. Moreover, routes of ischemic Ca²⁺ influx to neurons, involvement of intracellular Ca²⁺ stores and Ca²⁺ buffers, spatial and temporal relations between ischemia-induced increases in intracellular Ca²⁺ concentration and neurotoxicity will further increase our understanding about underlying mechanism and they can act as a target for the development of drugs. Here, in our article we are trying to provide a brief overview of various Ca²⁺ influx pathways involve in ischemic neuron and how ischemic neuron attempts to counterbalance this calcium overload.