Marijke De Couck

Facebook: A literature review

This article provides a critical review of scientific, peer reviewed, articles on Facebook between 2006 and 2012. The review shows that while there are yet numerous articles on various aspects of the social network site, there are still many gaps to be filled. Also, due to the limited scope of many articles (in sample sizes as well as in the number of countries included in the studies) and frequent changes to Facebook’s design and features, it is not only necessary to revisit many of these articles but also to integrate their research findings. The review ends with a critical discussion and directions for future research.

You may need the vagus nerve to understand pathophysiology and to treat diseases.

Can different pathophysiological mechanisms and risk factors leading to various diseases be linked with altered transmission of signals by one common pathway? The present article provides evidence for the hypothesis that adequate vagal nerve activity reduces the risk of major diseases, via common basic mechanisms and interim risk factors. These diseases include cardiovascular disease, cancer, Alzheimers disease and the metabolic syndrome. Three basic mechanisms contribute to such illnesses: local oxidative stress and DNA damage, inflammatory reactions and excessive sympathetic responses, all of which are inhibited by vagal nerve activity. Efferent vagal activity that can be non-invasively measured by HRV (heart rate variability), derived from an ECG, is inversely related to all three basic mechanisms, to various risk factors (e.g. diabetes and dyslipidaemia) and, more broadly, to the diseases as well. Finally, vagal activity is proposed to moderate the effects of risk factors on developing such illnesses. By proposing an integrative neurobiological model of major diseases, identifying people at risk for, and treating patients with, such diseases may be done more efficiently. People with low HRV may be identified and subsequently treated by vagus nerve activation to possibly prevent or treat such illnesses. This proposed disease paradigm may have important preventative and therapeutic implications, whose clinical effects need to be investigated.

You may need a nerve to treat pain: the neurobiological rationale for vagal nerve activation in pain management.

Objectives:Pain is a complex common health problem, with important implications for quality of life and with huge economic consequences. Pain can be elicited due to tissue damage, as well as other multiple factors such as inflammation and oxidative stress. Can there be 1 therapeutic pathway that may target multiple etiologic factors in pain? Methods:In the present article, we review evidence for the relationships between vagal nerve activity and pain, and between vagal nerve activity and 5 factors that are etiologic to or protective in pain. Results:Vagal nerve activity inhibits inflammation, oxidative stress, and sympathetic activity, activates brain regions that can oppose the brain “pain matrix,” and finally it might influence the analgesic effects of opioids. Together, these can explain the antinociceptive effects of vagal nerve activation or of acetylcholine, the principal vagal nerve neurotransmitter. These findings form an evidence-based neurobiological rationale for testing and possibly implementing different vagal nerve−activating treatments in pain conditions. Discussion:In this article, we show evidence for the relationships between vagal nerve activity and pain, and between vagal nerve activity and 5 factors that are etiologic to pain. Given the evidence and effects of the vagus nerve activation in pain, people involved in pain therapy may need to seriously consider activation of this nerve.

The Role of the Vagus Nerve in Cancer Prognosis: A Systematic and a Comprehensive Review

This article reviews the role of the vagus nerve in tumor modulation and cancer prognosis. We present a systematic review of 12 epidemiological studies examining the relationship between heart rate variability, the main vagus nerve index, and prognosis in cancer patients (survival and tumor markers). These studies show that initially high vagal nerve activity predicts better cancer prognosis, and, in some studies, independent of confounders such as cancer stage and treatments. Since the design of the epidemiological studies is correlational, any causal relationship between heart rate variability and cancer prognosis cannot be inferred. However, various semi-experimental cohort studies in humans and experimental studies in animals have examined this causal relationship. The second part of this paper presents a comprehensive review including human and animal cohort and experimental studies showing that vagotomy accelerates tumor growth, while vagal nerve activation improves cancer prognosis. Based on all reviewed studies, it is concluded that the evidence supports a protective role of the vagus nerve in cancer and specifically in the metastatic stage.

The Vagus Nerve Can Predict and Possibly Modulate Non-Communicable Chronic Diseases: Introducing a Neuroimmunological Paradigm to Public Health

Global burden of diseases (GBD) includes non-communicable conditions such as cardiovascular diseases, cancer and chronic obstructive pulmonary disease. These share important behavioral risk factors (e.g., smoking, diet) and pathophysiological contributing factors (oxidative stress, inflammation and excessive sympathetic activity). This article wishes to introduce to medicine and public health a new paradigm to predict, understand, prevent and possibly treat such diseases based on the science of neuro-immunology and specifically by focusing on vagal neuro-modulation. Vagal nerve activity is related to frontal brain activity which regulates unhealthy lifestyle behaviors. Epidemiologically, high vagal activity, indexed by greater heart rate variability (HRV), independently predicts reduced risk of GBD and better prognosis in GBD. Biologically, the vagus nerve inhibits oxidative stress, inflammation and sympathetic activity (and associated hypoxia). Finally, current non-invasive methods exist to activate this nerve for neuro-modulation, and have promising clinical effects. Indeed, preliminary evidence exists for the beneficial effects of vagal nerve activation in diabetes, stroke, myocardial infarction and possibly cancer. Thus, we propose to routinely implement measurement of HRV to predict such GBD in populations, and to test in randomized controlled trials effects of non-invasive vagal nerve activation on prevention and treatment of GBD, reflecting possible neuro-modulation of health.

Therapeutic potential of the vagus nerve in cancer

Accumulating evidence points to a beneficial effect ofvagus nerve activity in tumor development. The vagus nerve is proposed to slow tumorigenesis because of its anti-inflammatory properties mediated through ACh and the α7nAChR. Since α7nAChRs are widely expressed by many types of immune cells we hypothesized that the vagus nerve affects the tumor microenvironment and anticancer immunity. We found direct evidence in studies using animal cancer models that vagus nerve stimulation alters immunological responses relevant to the tumor microenvironment. Also studies in pathologies other than cancer suggest a role for the vagus nerve in altering immunological responses relevant to anticancer immunity. These results provide a rationale to expect that vagus nerve stimulation, in combination with conventional cancer treatments, may improve the prognosis of cancer patients by promoting anticancer immunity.

Linking numbers to perceptions and experiences: Why we need transdisciplinary mixed-methods combining neurophysiological and qualitative data

Today, more and more problems that scientists need to tackle are complex problems. Many examples of these can be found in the health sciences, medicine and ecology. Typical features of complex problems are that they cannot be studied by one discipline and that they need to take into account subjective data as well as objective data. Two promising responses to deal with complex problems are Transdisciplinary and Mixed Method approaches. However, there is still a lacuna to fill, with transdisciplinary studies bridging the social sciences and biomedical sciences. More specifically, we need more and better studies that combine qualitative data about subjective experiences, perception and so on with objective, quantitative, neurophysiological data. We believe that the combination of qualitative and neurophysiological data is a good example of what we would like to call transdisciplinary mixed methods. In this article, we aim to explore the opportunities of transdisciplinary mixed-methods studies in which qualitative and neurophysiological data are used. We give a brief overview of what is characteristic for this kind of studies and illustrate this with examples; we point out strengths and limitations and propose an agenda for the future. We conclude that transdisciplinary mixed-methods studies in which qualitative and neurophysiological data are used have the potential to improve our knowledge about complex problems. A main obstacle seems to be that most scientists from the biomedical sciences are not familiar with the (qualitative) methods from the social sciences and vice versa. To end this ‘clash of paradigms’™, we urgently need to cultivate transdisciplinary thinking.