Introduction: Continuous positive airway pressure (CPAP) therapy remains the standard treatment for obstructive sleep apnea. However, its proven effect is useless if the patient does not tolerate the treatment. The electrical stimulation approach has been investigated for several decades now and it seems that the implantable devices for invasive electrical stimulation of hypoglossal nerve are viewed as effective with some of them already approved for human use.Areas covered: in this review, we intent to summarize the existing records of noninvasive stimulation in sleep apnea to make the scientific community aware of the details before deciding on its future. We believe that this is a battle still to fight and more could be done bearing in mind the safety of this method.Expertopinion: noninvasive electrical stimulation has been left behind based on few, small and inconsistent studies using different stimulation parameters. These studies are difficult to compare and to draw conclusions.Electrical stimulation is a field for research in the treatment of obstructive sleep apnea, with many aspects still to be discovered, and which may become a therapeutic alternative to the use of CPAP in certain patients.
Keywords: Sleep apnea; genioglossus muscle; noninvasive electrical stimulation; sublingual electrical stimulation; transcutaneous electrical stimulation; upper airway stimulation.