Papers of the Week

In a recent issue, Kovacic et al. analyze data from a randomized sham-controlled trial and show that pretreatment vagal efficiency, an index related to respiratory sinus arrhythmia, is a predictor of pain improvement in adolescents with functional abdominal pain when treated with auricular percutaneous electrical nerve field stimulation. The underlying premise is the polyvagal hypothesis, an explanatory framework for the evolution of the mammalian autonomic nervous system, which proposes that functional gastrointestinal disorders can result from a chronic maladaptive state of autonomic neural control mechanisms after traumatic stress. This is an opportunity for us to stimulate physicians' interest in evolutionary medicine.