Stimulation of the vagus nerve, a parasympathetic nerve that controls the neuro-digestive, vascular, and immune systems, induces pain relief, particularly in clinical conditions such as headache and rheumatoid arthritis. Transmission through vagal afferents towards the nucleus of the solitary tract (NST), the central relay nucleus of the vagus nerve, has been proposed as the main physiological mechanism that reduces pain intensity after vagal stimulation. Chronic pain symptoms of fibromyalgia patients might benefit from stimulation of the vagus nerve via normalization of altered autonomic and immune systems causing their respective symptoms. However, multi-session non-invasive vagal stimulation effects on fibromyalgia have not been evaluated in randomized clinical trials. We propose a parallel group, sham-controlled, randomized study to modulate the sympathetic–vagal balance and pain intensity in fibromyalgia patients by application of non-invasive transcutaneous vagus nerve stimulation (tVNS) over the vagal auricular and cervical branches. We will recruit 136 fibromyalgia patients with chronic moderate to high pain intensity. The primary outcome measure will be pain intensity, and secondary measures will be fatigue, health-related quality of life, sleep disorders, and depression. Heart rate variability and pro-inflammatory cytokine levels will be obtained as secondary physiological measures. We hypothesize that multiple tVNS sessions (five per week, for 4 weeks) will reduce pain intensity and improve quality of life as a result of normalization of the vagal control of nociception and immune–autonomic functions. Since both vagal branches project to the NST, we do not predict significantly different results between the two stimulation protocols.

Background The elderly population has proven to be a particularly vulnerable group with regard to the effects of the COVID-19 pandemic. The aim of this study was to study the psychometric properties of the Ansiedad y MIedo a Covid-19 scale (AMICO) on a population-based sample of elderly people. Methods A descriptive and psychometric cross-sectional study, based on questionnaires, was carried out. An exploratory and confirmatory factor analysis was performed, as well as a bivariate analysis between the different sociodemographic variables with respect to the total scale score. Results A sample of 720 adults over 65 years of age was obtained, 52.2% of whom were women. The structure of the factor of the scale showed two factors (fear and anxiety) and was confirmed with good fit parameters. The overall reliability of the scale in terms of internal consistency was α = 0.94. Conclusions The AMICO scale is a valid and reliable instrument to measure anxiety and fear of COVID-19 in the Spanish population over 65 years of age. Women and subjects with a partner showed the highest values of fear and anxiety.

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation procedure to modulate cortical excitability and related brain functions. tDCS can effectively alter multiple brain functions in healthy humans and is suggested as a therapeutic tool in several neurological and psychiatric diseases. However, variability of results is an important limitation of this method. This variability may be due to multiple factors, including age, head and brain anatomy (including skull, skin, CSF and meninges), cognitive reserve and baseline performance level, specific task demands, as well as comorbidities in clinical settings. Different electrode montages are a further source of variability between tDCS studies. A procedure to estimate the electric field generated by specific tDCS electrode configurations, which can be helpful to adapt stimulation protocols, is the computational finite element method. This approach is useful to provide a priori modeling of the current spread and electric field intensity that will be generated according to the implemented electrode montage. Here, we present standard, non-personalized model-based electric field simulations for motor, dorsolateral prefrontal, and posterior parietal cortex stimulation according to twenty typical tDCS electrode configurations using two different current flow modeling software packages. The resulting simulated maximum intensity of the electric field, focality, and current spread were similar, but not identical, between models. The advantages and limitations of both mathematical simulations of the electric field are presented and discussed systematically, including aspects that, at present, prevent more widespread application of respective simulation approaches in the field of non-invasive brain stimulation.

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Background The aim of this study was to assess the presence of anxiety, fear and psychological distress in the population of people over 65 years of age and to study possible differences with a sample of subjects aged between 60 and 65 years. Methods A descriptive and psychometric cross‐sectional study. The total sample used consisted of 1112 subjects from university training programmes for the old people from all over Spain. Anxiety and fear of COVID‐19 were measured using the AMICO scale and psychological distress using the GHQ‐12 instrument. Results Significant differences were found in the AMICO ( p = 0.006) and GHQ‐12 ( p = 0.03) measures between age subgroups, with lower values in older age groups. Contrast statistics showed significant differences on both measures (AMICO and GHQ) in women, single or widowed subjects, and those who had not been infected by the SARS‐CoV‐2 virus. Limitations It would be desirable to increase the sample size, especially in the lower age group (<65). The establishment of the age limit between the two groups could be located at 60 years of age. The use of new technologies to get information should be considered. Conclusions Overall, moderate levels of fear and anxiety of COVID‐19 were present. Women tended to have higher levels of both general psychological distress and fear and anxiety of COVID‐19. Especially in those over 65, higher levels of distress and fear/anxiety of COVID‐19 were associated with being widowed or single, and not having been infected before with SARS‐CoV‐2.