Sleep apnoea related to brain injury

Children with sleep apnoea are at a high risk of developing neuronal brain injury, with consequent effect on IQ and cognitive functions.In sleep apnoea, the muscles of the throat relax to the point of blocking the airway above the voice box. The breathing stops, for between a few seconds and up to one minute, until the brain registers the lack of breathing or a drop in oxygen levels and sends a small wake-up call. The sleeper rouses slightly, typically snorts and gasps, then drifts back to sleep almost immediately. Researchers from the Johns Hopkins University School of Medicine in Baltimore found that untreated sleep apnoea in children can cause neuronal brain injury. They also found changes that suggest injury in areas of the brain that house critical cognitive functions, such as attention, learning, and working memory.Previous reports have related childhood sleep apnoea to deficits in memory, learning and other mental functions, but no studies have demonstrated neuronal injury. The researching team performed sleep studies and neuropsychologic assessments in 19 children with moderate to severe sleep apnoea and in comparison groups of 12 similar but healthy control children. In addition, six of the sleep apnoea patients and six matched controls underwent specialized MRI exams to assess the state of brain neurons.Consistent with earlier research, verbal working memory and verbal fluency were impaired in children with sleep apnoea. Moreover, the average IQ of the sleep apnoea group was just 86 compared with 101 in the control group. The MRI scans revealed metabolic changes suggesting neuronal injury in two specific areas of the brain in the children with sleep apnoea.The researchers stated that its not certain that sleep apnoea causes the injury, but there is a very strong association between changes in the neurons of the hippocampus and the right frontal cortex and IQ and other cognitive functions. Further research is needed to determine if early diagnosis and treatment of sleep apnoea can reverse the neurological deficits identified in the study. Sleep apnoea can be treated with pressurised air delivered by a facemask, to keep the airways open while a person sleeps.