Transcranial Electrical Stimulation for Psychiatric Disorders in Adults: A Primer

Neuromodulation Strategies in Lifelong Bipolar Disorder: A Narrative Review

Bipolar disorder is a debilitating psychiatric condition characterized by recurrent episodes of mania and depression, affecting millions worldwide. While pharmacotherapy remains the cornerstone of treatment, a significant proportion of patients exhibit inadequate response or intolerable side effects to conventional medications. In recent years, neuromodulation techniques have emerged as promising adjunctive or alternative treatments for bipolar disorder. We performed a narrative review, according to the Scale for the Assessment of Narrative Review Articles (SANRA) guidelines, to provide a comprehensive overview of the current literature on neuromodulation interventions in bipolar disorder across the course of lifespan. Specifically, it examines the efficacy, safety, and mechanisms of action of various neuromodulation strategies, including, among others, transcranial magnetic stimulation (TMS), electroconvulsive therapy (ECT), vagus nerve stimulation (VNS), deep brain stimulation (DBS), and it describes the therapeutic experiences across the different ages of illness. Additionally, this review discusses the clinical implications, challenges, and future directions of the integration, in clinical practice, of neuromodulation into the management of bipolar disorder. By synthesizing evidence from different studies, this review aims to inform clinicians, researchers, and stakeholders about the evolving landscape of neuromodulation treatments and their potential role in improving outcomes for individuals with bipolar disorder.

Advances in conductive hydrogels for neural recording and stimulation

The brain-computer interface (BCI) allows the human or animal brain to directly interact with the external environment through the neural interfaces, thus playing the role of monitoring, protecting, improving/restoring, enhancing, and replacing. Recording electrophysiological information such as brain neural signals is of great importance in health monitoring and disease diagnosis. According to the electrode position, it can be divided into non-implantable, semi-implantable, and implantable. Among them, implantable neural electrodes can obtain the highest-quality electrophysiological information, so they have the most promising application. However, due to the chemo-mechanical mismatch between devices and tissues, the adverse foreign body response and performance loss over time seriously restrict the development and application of implantable neural electrodes. Given the challenges, conductive hydrogel-based neural electrodes have recently attracted much attention, owing to many advantages such as good mechanical match with the native tissues, negligible foreign body response, and minimal signal attenuation. This review mainly focuses on the current development of conductive hydrogels as a biocompatible framework for neural tissue and conductivity-supporting substrates for the transmission of electrical signals of neural tissue to speed up electrical regeneration and their applications in neural sensing and recording as well as stimulation.

Application of Transcranial Direct and Alternating Current Stimulation (tDCS and tACS) on Major Depressive Disorder

The exploration of brain stimulation methods offers a promising avenue to overcome the shortcomings of traditional drug therapies and psychological treatments for major depressive disorder (MDD). Over the past years, there has been an increasing focus on transcranial electrical stimulation (tES), notably for its ease of use and potentially fewer side effects. This chapter delves into the use of transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), which are key components of tES, in managing depression. It begins by introducing tDCS and tACS, summarizing their action mechanisms. Following this introduction, the chapter provides an in-depth analysis of existing meta-analyses, systematic reviews, clinical studies, and case reports that have applied tES in MDD treatment. It also considers the role of tES in personalized medicine by looking at specific patient groups and evaluating research on possible biomarkers that could predict how patients with MDD respond to tES therapy.

[The use of transcranial micropolarization in the acute period of severe traumatic brain injury in children]

Traumatic brain injury, which is often considered as a silent epidemic, is a public health problem. The duration of acute recovery period remains a commonly used criterion for injury severity and clinical management. In this connection, the first stage of medical rehabilitation is carried out in the conditions of resuscitation and neurosurgery department in the hospital providing specialized care. Rehabilitation techniques such as postural training, phase verticalization, individual kinesiotherapy, transcranial micropolarization and etc. are used.

OBJECTIVE

To assess the effectiveness of using transcranial micropolarization in acute period of severe traumatic brain injury in children.

MATERIAL AND METHODS

The study on the effectiveness of using transcranial micropolarization in acute period of severe traumatic brain injury in 85 children, divided into 2 groups, was carried out. The study group (42 patients) received the transcranial micropolarization on the 2nd day after severe traumatic brain injury. The control group (43 patients) received only rehabilitation in neurosurgery department. The neurological status in the patients of both groups was assessed on the 2nd day after severe traumatic brain injury in resuscitation department, and after 1, 3 and 6 months.

RESULTS AND CONCLUSION

The inclusion of transcranial micropolarization in the early medical rehabilitation of children with severe traumatic brain injury increases consciousness level in a shorter period of time, that predicts early patient's socialization.

Brain stimulation treatment for bipolar disorder

AIMS

Bipolar disorders are clinically complex, chronic and recurrent disorders. Few treatment options are effective across hypomanic, manic, depressive and mixed states and as continuation or maintenance treatment after initial symptom remission. The aim of this review was to provide an up-to-date overview of research on the efficacy, tolerability and cognitive effects of electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), magnetic seizure therapy (MST), deep brain stimulation (DBS) and vagus nerve stimulation (VNS).

METHODS

References included in this review were identified through multiple searches of the Embase, PubMed/MEDLINE and APA PsycINFO electronic databases for articles published from inception until February 2022. Published reviews, meta-analyses, randomised controlled trials and recent studies were prioritised to provide a comprehensive and up-to-date overview of research on brain stimulation in patients with bipolar disorders.

RESULTS

The evidence base for brain stimulation as an add-on or alternative to pharmacological and psychological treatments in patients with bipolar disorders is limited but rapidly expanding. Brain stimulation treatments represent an opportunity to treat all bipolar disorder states, including cognitive dysfunction during euthymic periods.

CONCLUSION

Whilst findings to date have been encouraging, larger randomised controlled trials with long-term follow-up are needed to clarify important questions regarding treatment efficacy and tolerability, the frequency of treatment-emergent affective switches and effects on cognitive function.