Beyond the treatment of epilepsy: new applications of vagus nerve stimulation in psychiatry.
ABSTRACT Vagus nerve stimulation (VNS) in humans generally refers to stimulation of the left vagus nerve at the cervical level VNS is an established treatment largely devoid of severe side effect for medically refractory partial onset seizures and has been used in more than 16,000 patients. Over the past 5 years, applications in other neuropsychiatric disorders have been investigated with a special emphasis on depression. Recent data from an open-label, multi-center pilot study involving 60 patients suggest a potential clinical usefulness in the acute and maintenance treatment of drug-resistant depressive disorder. The perspective of VNS as along-term treatment with the advantage of assured compliance makes it an interesting technique to potentially treat drug-resistant depression. However, definite therapeutic effects of clinical significance remain to be confirmed in large placebo-controlled trial. Results of clinical pilot studies involving patients suffering from obesity and Alzheimer's disease indicate that VNS might induce weight loss and improve cognition. Besides its clinical usefulness, VNS can be used as a research tool, allowing neurophysiologic investigations of the parasympathetic system and its interactions with other parts of the central nervous system.
SourceAvailable from: Hans Ågren
Dataset: The hidden third
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ABSTRACT: The ability to alter one's emotional responses is central to overall well-being and to effectively meeting the demands of life. One of the chief symptoms of events such as trauma, that overwhelm our capacities to successfully handle and adapt to them, is a shift in our internal baseline reference such that there ensues a repetitive activation of the traumatic event. This can result in high vigilance and over-sensitivity to environmental signals which are reflected in inappropriate emotional responses and autonomic nervous system dynamics. In this article we discuss the perspective that one's ability to self-regulate the quality of feeling and emotion of one's moment-to-moment experience is intimately tied to our physiology, and the reciprocal interactions among physiological, cognitive, and emotional systems. These interactions form the basis of information processing networks in which communication between systems occurs through the generation and transmission of rhythms and patterns of activity. Our discussion emphasizes the communication pathways between the heart and brain, as well as how these are related to cognitive and emotional function and self-regulatory capacity. We discuss the hypothesis that self-induced positive emotions increase the coherence in bodily processes, which is reflected in the pattern of the heart's rhythm. This shift in the heart rhythm in turn plays an important role in facilitating higher cognitive functions, creating emotional stability and facilitating states of calm. Over time, this establishes a new inner-baseline reference, a type of implicit memory that organizes perception, feelings, and behavior. Without establishing a new baseline reference, people are at risk of getting "stuck" in familiar, yet unhealthy emotional and behavioral patterns and living their lives through the automatic filters of past familiar or traumatic experience.Frontiers in Psychology 09/2014; 5:1090. DOI:10.3389/fpsyg.2014.01090 · 2.80 Impact Factor
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ABSTRACT: Heart rate variability, the change in the time intervals between adjacent heartbeats, is an emergent property of interdependent regulatory systems that operates on different time scales to adapt to environmental and psychological challenges. This article briefly reviews neural regulation of the heart and offers some new perspectives on mechanisms underlying the very low frequency rhythm of heart rate variability. Interpretation of heart rate variability rhythms in the context of health risk and physiological and psychological self-regulatory capacity assessment is discussed. The cardiovascular regulatory centers in the spinal cord and medulla integrate inputs from higher brain centers with afferent cardiovascular system inputs to adjust heart rate and blood pressure via sympathetic and parasympathetic efferent pathways. We also discuss the intrinsic cardiac nervous system and the heart-brain connection pathways, through which afferent information can influence activity in the subcortical, frontocortical, and motor cortex areas. In addition, the use of real-time HRV feedback to increase self-regulatory capacity is reviewed. We conclude that the heart's rhythms are characterized by both complexity and stability over longer time scales that reflect both physiological and psychological functional status of these internal self-regulatory systems.01/2015; 4(1):46-61. DOI:10.7453/gahmj.2014.073