Paralysis on one side of the brain (IMAGE) Trinity College Dublin Caption An MRI-based image obtained through a technique called arterial spin labelling, which allows scientists to image blood flow rates in the brain. The image shows a huge increase in blood flow (red) during an acute stage of hemiplegia (one-sided paralysis) in a child diagnosed with alternating hemiplegia of childhood (AHC), caused by a mutation in the CLDN5 gene. Credit Prof. Matthew Campbell, Trinity College Dublin Usage Restrictions None License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.