Sudden Infant Death Syndrome (SIDS) and Sudden Unexpected Death in Epilepsy (SUDEP) are syndromes that share many medical similarities but whose physiological causes are poorly understood. An opinion article publishing March 21 in the journal Trends in Neurosciences suggests that the inability for an individual to wake up when their CO2 blood levels rise, likely due to a faulty neural reflex, may be a shared cause for incidences of death in both disorders.