The Onset of Diabetes During Transcranial Direct Current Stimulation Treatment of Anorexia Nervosa - A Case Report

Molecular Insights into Transcranial Direct Current Stimulation Effects: Metabolomics and Transcriptomics Analyses

INTRODUCTION

Transcranial direct current stimulation (tDCS) is an evolving non-invasive neurostimulation technique. Despite multiple studies, its underlying molecular mechanisms are still unclear. Several previous human studies of the effect of tDCS suggest that it generates metabolic effects. The induction of metabolic effects by tDCS could provide an explanation for how it generates its long-term beneficial clinical outcome.

AIM

Given these hints of tDCS metabolic effects, we aimed to delineate the metabolic pathways involved in its mode of action.

METHODS

To accomplish this, we utilized a broad analytical approach of co-analyzing metabolomics and transcriptomic data generated from anodal tDCS in rat models. Since no metabolomic dataset was available, we performed a tDCS experiment of bilateral anodal stimulation of 200 µA for 20 min and for 5 consecutive days, followed by harvesting the brain tissue below the stimulating electrode and generating a metabolomics dataset using LC-MS/MS. The analysis of the transcriptomic dataset was based on a publicly available dataset.

RESULTS

Our analyses revealed that tDCS alters the metabolic profile of brain tissue, affecting bioenergetic-related pathways, such as glycolysis and mitochondrial functioning. In addition, we found changes in calcium-related signaling.

CONCLUSIONS

We conclude that tDCS affects metabolism by modulating energy production-related processes. Given our findings concerning calcium-related signaling, we suggest that the immediate effects of tDCS on calcium dynamics drive modifications in distinct metabolic pathways. A thorough understanding of the underlying molecular mechanisms of tDCS has the potential to revolutionize its applicability, enabling the generation of personalized medicine in the field of neurostimulation and thus contributing to its optimization.

Effects of bilateral dorsolateral prefrontal cortex high-definition transcranial direct-current stimulation on time-trial performance in cyclists with type 1 diabetes mellitus

BACKGROUND

HD-tDCS is capable to increase the focality of neuromodulation and has been recently applied to improve endurance performance in healthy subjects.

OBJECTIVE/HYPOTHESIS

Whether these putative advantages could be exploited in active subjects with type 1 diabetes mellitus (T1D) remains questionable.

METHODS

In a double-blind, randomized crossover order, 11 high-level cyclists (27 ± 4.3 years; weight: 65.5 ± 8.6 kg; height: 180 ± 8 cm; VO₂peak: 67.5 ± 2.9 mL min^-1 kg^-1) with T1D underwent either HD-tDCS (F3, F4) or control (SHAM) and completed a constant-load trial (CLT) at 75% of the 2nd ventilatory threshold plus a 15-km cycling time-trial (TT).

RESULTS

After HD-tDCS, the total time to cover the TT was 3.8% faster (P < 0.01), associated with a higher mean power output (P < 0.01), and a higher rate of power/perception of effort (P < 0.01) and power/heart rate at iso-time (P < 0.05) than the SHAM condition. Physiological parameters during CLT and TT did not differ in both conditions.

CONCLUSIONS

These findings suggest that upregulation of the prefrontal cortex could enhance endurance performance in high-level cyclists with T1D, without altering physiological and perceptual responses at moderate intensity. Present data open to future applications of HD-tDCS to a wider population of active T1D-subjects.

Neuromodulation and Eating Disorders

PURPOSE OF REVIEW

We review recent evidence on the use of neuromodulation for treating eating disorders (EDs), including anorexia nervosa, bulimia nervosa and binge eating disorder. We evaluate studies on (a) modern non-invasive methods of brain stimulation, such as transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), (b) electroconvulsive therapy (ECT) and (c) more invasive techniques, including deep brain stimulation (DBS).

RECENT FINDINGS

Most reports on the clinical applications of neuromodulation in EDs are limited to case studies, case series and small clinical trials. The majority have focused on severe, enduring and hard-to-treat cases of AN. In this population, data suggest that both rTMS and DBS have therapeutic potential and are safe and acceptable. High-quality clinical trials in different ED populations are needed which investigate different stimulation methods, sites and parameters, the use of neuromodulation as stand-alone and/or adjunctive treatment, as well as the mechanisms of action.

Effects of Transcranial Direct Current Stimulation Treatment for Anorexia Nervosa

Background: Anorexia nervosa (AN) is a life-threatening illness with poor treatment outcomes. Although transcranial direct current stimulation (tDCS) is a promising non-invasive brain stimulation method, its effect in patients with AN remains unclear. Objective: This study investigated changes in maladaptive eating behavior, body mass index (BMI), and depression after 10 sessions of anodal tDCS over the left dorsolateral prefrontal cortex (DLPFC). Methods: In this double-blind, randomized controlled trial, 43 inpatients with AN were divided to receive either active (n = 22) or sham (n = 21) tDCS over the left DLPFC (anode F3/cathode Fp2, 2 mA for 30 min). All patients filled the Eating Disorder Examination Questionnaire (EDE-Q) and Zung Self-Rating Depression Scale (ZUNG), and their BMI was measured. These values were obtained repeatedly in four stages: (1) before tDCS treatment, (2) after tDCS treatment, (3) in the follow-up after 2 weeks, and (4) in the follow-up after 4 weeks. Results: Primary outcomes (EDE-Q) based on the ANOVA results do not show any between-group differences either after the active part of the study or in the follow-up. Secondary analysis reveals a reduction in some items of EDE-Q. Compared with sham tDCS, active tDCS significantly improved self-evaluation based on body shape (p < 0.05) and significantly decreased the need of excessive control over calorie intake (p < 0.05) in the 4-week follow-up. However, the results do not survive multiple comparison correction. In both sham and active groups, the BMI values improved, albeit not significantly. Conclusion: We did not observe a significant effect of tDCS over the left DLPFC on complex psychopathology and weight recovery in patients with AN. tDCS reduced the need to follow specific dietary rules and improved body image evaluation in patients with AN. Tests with a larger sample and different positions of electrodes are needed. Clinical Trial Registration: www.ClinicalTrials.gov, identifier: NCT03273205.