Clinical neuromodulatory effects of deep brain stimulation in disorder of consciousness: A literature review

Abstract

BackgroundThe management of patients with disorders of consciousness (DOC) presents substantial challenges in clinical practice. Deep brain stimulation (DBS) has emerged as a potential therapeutic approach, but the lack of standardized regulatory parameters for DBS in DOC hinders definitive conclusions.ObjectiveThis comprehensive review aims to provide a detailed summary of the current issues concerning patient selection, target setting, and modulation parameters in clinical studies investigating the application of DBS for DOC patients.MethodsA meticulous systematic analysis of the literatures was conducted, encompassing articles published from 1968 to April 2023, retrieved from reputable databases (PubMed, Embase, Medline, and Web of Science).ResultsThe systematic analysis of 21 eligible articles, involving 146 patients with DOC resulting from acquired brain injury or other disorders, revealed significant insights. The most frequently targeted regions were the Centromedian‐parafascicular complex (CM‐pf) nuclei and central thalamus (CT), both recognized for their role in regulating consciousness. However, other targets have also been explored in different studies. The stimulation frequency was predominantly set at 25 or 100 Hz, with pulse width of 120 μs, and voltages ranged from 0 to 4 V. These parameters were customized based on individual patient responses and evaluations. The overall clinical efficacy rate in all included studies was 39.7%, indicating a positive effect of DBS in a subset of DOC patients. Nonetheless, the assessment methods, follow‐up durations, and outcome measures varied across studies, potentially contributing to the variability in reported efficacy rates.ConclusionDespite the challenges arising from the lack of standardized parameters, DBS shows promising potential as a therapeutic option for patients with DOC. However, there still remains the need for standardized protocols and assessment methods, which are crucial to deepen the understanding and optimizing the therapeutic potential of DBS in this specific patient population.

The efficacy and safety of bilateral synchronous transcutaneous auricular vagus nerve stimulation for prolonged disorders of consciousness: a multicenter, double-blind, stratified, randomized controlled trial protocol

“…Despite great efforts in medication therapy, neuromodulation and physical rehabilitation, the successful treatment strategy of DOC remains limited, primarily due to a profound lack of comprehension of the underlying pathophysiology (32). In recent years, there has been a growing interest in VNS as a potential therapeutic approach, encompassing both invasive and non-invasive techniques.…”

Anatomical-related factors and outcome of percutaneous short-term spinal cord stimulation electrode shift in patients with disorders of consciousness: a retrospective study

“…Among these, neuromodulation techniques offer a novel approach to facilitating changes in the patients’ brain activity patterns in hopes of restoring consciousness ( Vanhoecke and Hariz, 2017 ; Wu et al, 2023 ). This method represents an emerging frontier in the treatment of disorders of consciousness, attempting to bridge the gap between the damaged neuronal pathways and the complex network that governs wakefulness and awareness ( Raguz et al, 2021 ; Cao et al, 2023 ).…”