Brain stimulation for patients with multiple sclerosis: an umbrella review of therapeutic efficacy

Efficacy of brain stimulation therapies across psychiatric, movement, and cognitive disorders: an umbrella review synthesizing meta-analyses of randomized controlled trials

BACKGROUND

Brain stimulation therapy (BST) has significant potential in treating psychiatric, movement, and cognitive disorders. Given the high prevalence of comorbidities among these disorders, we conducted an umbrella review to comprehensively assess the efficacy of BSTs in treating the core symptoms across these three categories of disorders.

METHODS

We systematically searched for meta-analyses and network meta-analyses of randomized controlled trials with sham controls up to September 25, 2024, from databases including PubMed, PsycINFO, Embase, and the Cochrane Library. Our primary outcome was improvements in core symptoms. We evaluated quality using 11 criteria. We calculated pooled effect estimates for core symptoms based on the largest meta-analyses, then conducted sensitivity and subgroup analyses, and assessed heterogeneity, publication bias, and small-study effects. Finally, we synthesized effect sizes from all meta-analyses to provide a comprehensive overview of BSTs' efficacy. PROSPERO registration: CRD42023439090.

FINDINGS

We included 198 articles with 108,377 patients evaluating 14 BSTs across 21 disorders. The largest meta-analysis showed a moderate standardized mean difference (SMD) of 0.56 (95% CI: 0.49, 0.64; I2 = 70%). Subgroup analyses revealed significant SMDs for psychiatric disorders (0.60; 95% CI: 0.49, 0.71; I2 = 66%), movement disorders (0.56; 95% CI: 0.42, 0.69; I2 = 79%), and cognitive disorders (0.46; 95% CI: 0.32, 0.61; I2 = 48%). SMDs were 0.44 (95% CI: 0.23, 0.65; I2 = 70%) for follow-up ≤1 month and 0.69 (95% CI: 0.43, 0.94; I2 = 84%) for follow-up >1 month. Compared to other conditions, BSTs show better therapeutic effects in treating depression, post-traumatic stress disorder, obsessive-compulsive disorder, pain, fibromyalgia, and post-stroke motor recovery.

INTERPRETATION

This review explored the potential of BSTs for comorbidities of the three disorders from a disorder-specific perspective, providing a roadmap for their clinical application and future research.

FUNDING

This work was supported by the Anhui Natural Science Foundation (2023AH040086), Key Laboratory of Philosophy and Social Science of Anhui Province on Adolescent Mental Health and Crisis Intelligence Intervention (SYS2023B08), and the Joint Funds of the National Natural Science Foundation of China (U23A20424).

Advances in Brain Stimulation, Nanomedicine and the Use of Magnetoelectric Nanoparticles: Dopaminergic Alterations and Their Role in Neurodegeneration and Drug Addiction

Recent advancements in brain stimulation and nanomedicine have ushered in a new era of therapeutic interventions for psychiatric and neurodegenerative disorders. This review explores the cutting-edge innovations in brain stimulation techniques, including their applications in alleviating symptoms of main neurodegenerative disorders and addiction. Deep Brain Stimulation (DBS) is an FDA-approved treatment for specific neurodegenerative disorders, including Parkinson's Disease (PD), and is currently under evaluation for other conditions, such as Alzheimer's Disease. This technique has facilitated significant advancements in understanding brain electrical circuitry by enabling targeted brain stimulation and providing insights into neural network function and dysfunction. In reviewing DBS studies, this review places particular emphasis on the underlying main neurotransmitter modifications and their specific brain area location, particularly focusing on the dopaminergic system, which plays a critical role in these conditions. Furthermore, this review delves into the groundbreaking developments in nanomedicine, highlighting how nanotechnology can be utilized to target aberrant signaling in neurodegenerative diseases, with a specific focus on the dopaminergic system. The discussion extends to emerging technologies such as magnetoelectric nanoparticles (MENPs), which represent a novel intersection between nanoformulation and brain stimulation approaches. These innovative technologies offer promising avenues for enhancing the precision and effectiveness of treatments by enabling the non-invasive, targeted delivery of therapeutic agents as well as on-site, on-demand stimulation. By integrating insights from recent research and technological advances, this review aims to provide a comprehensive understanding of how brain stimulation and nanomedicine can be synergistically applied to address complex neuropsychiatric and neurodegenerative disorders, paving the way for future therapeutic strategies.