scholarly journals Non-invasive electrical brain stimulation for vision restoration after stroke: An exploratory randomized trial (REVIS)

2021 ◽  
pp. 1-15
Author(s):  
Silja Räty ◽  
Carolin Borrmann ◽  
Giuseppe Granata ◽  
Lizbeth Cárdenas-Morales ◽  
Ariel Schoenfeld ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Brain Stimulation ◽  
Homonymous Hemianopia ◽  
Electrical Brain Stimulation ◽  
Non Invasive ◽  
Before And After ◽  
Vision Restoration ◽  
The Individual ◽  
Double Blinded

Background: Occipital strokes often cause permanent homonymous hemianopia leading to significant disability. In previous studies, non-invasive electrical brain stimulation (NIBS) has improved vision after optic nerve damage and in combination with training after stroke. Objective: We explored different NIBS modalities for rehabilitation of hemianopia after chronic stroke. Methods: In a randomized, double-blinded, sham-controlled, three-armed trial, altogether 56 patients with homonymous hemianopia were recruited. The three experiments were: i) repetitive transorbital alternating current stimulation (rtACS, n = 8) vs. rtACS with prior cathodal transcranial direct current stimulation over the intact visual cortex (tDCS/rtACS, n = 8) vs. sham (n = 8); ii) rtACS (n = 9) vs. sham (n = 9); and iii) tDCS of the visual cortex (n = 7) vs. sham (n = 7). Visual functions were evaluated before and after the intervention, and after eight weeks follow-up. The primary outcome was change in visual field assessed by high-resolution and standard perimetries. The individual modalities were compared within each experimental arm. Results: Primary outcomes in Experiments 1 and 2 were negative. Only significant between-group change was observed in Experiment 3, where tDCS increased visual field of the contralesional eye compared to sham. tDCS/rtACS improved dynamic vision, reading, and visual field of the contralesional eye, but was not superior to other groups. rtACS alone increased foveal sensitivity, but was otherwise ineffective. All trial-related procedures were tolerated well. Conclusions: This exploratory trial showed safety but no main effect of NIBS on vision restoration after stroke. However, tDCS and combined tDCS/rtACS induced improvements in visually guided performance that need to be confirmed in larger-sample trials. NCT01418820 (clinicaltrials.gov)

scholarly journals The Role of Expectation and Beliefs on the Effects of Non-Invasive Brain Stimulation

2021 ◽  
Vol 11 (11) ◽  
pp. 1526
Author(s):  
Miriam Braga ◽  
Diletta Barbiani ◽  
Mehran Emadi Andani ◽  
Bernardo Villa-Sánchez ◽  
Michele Tinazzi ◽  
...  
Keyword(s):  
Brain Stimulation ◽  
Brain Area ◽  
Cortical Activation ◽  
Systematic Evaluation ◽  
Clinical Settings ◽  
Potential Contribution ◽  
Subjective Expectations ◽  
Non Invasive ◽  
Before And After ◽  
Nocebo Effects

Non-invasive brain stimulation (NIBS) techniques are used in clinical and cognitive neuroscience to induce a mild magnetic or electric field in the brain to modulate behavior and cortical activation. Despite the great body of literature demonstrating promising results, unexpected or even paradoxical outcomes are sometimes observed. This might be due either to technical and methodological issues (e.g., stimulation parameters, stimulated brain area), or to participants’ expectations and beliefs before and during the stimulation sessions. In this narrative review, we present some studies showing that placebo and nocebo effects, associated with positive and negative expectations, respectively, could be present in NIBS trials, both in experimental and in clinical settings. The lack of systematic evaluation of subjective expectations and beliefs before and after stimulation could represent a caveat that overshadows the potential contribution of placebo and nocebo effects in the outcome of NIBS trials.

scholarly journals Intraoperative Resting-State Functional Connectivity Based on RGB Imaging

Diagnostics ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2067
Author(s):  
Charly Caredda ◽  
Laurent Mahieu-Williame ◽  
Raphaël Sablong ◽  
Michaël Sdika ◽  
Fabien C. Schneider ◽  
...  
Keyword(s):  
Brain Stimulation ◽  
Resting State ◽  
Invasive Technique ◽  
Electrical Brain Stimulation ◽  
Resting State Networks ◽  
Brain Response ◽  
Resting State Functional Connectivity ◽  
Non Invasive ◽  
Marker Free ◽  
Neurosurgical Operation

RGB optical imaging is a marker-free, contactless, and non-invasive technique that is able to monitor hemodynamic brain response following neuronal activation using task-based and resting-state procedures. Magnetic resonance imaging (fMRI) and functional near infra-red spectroscopy (fNIRS) resting-state procedures cannot be used intraoperatively but RGB imaging provides an ideal solution to identify resting-state networks during a neurosurgical operation. We applied resting-state methodologies to intraoperative RGB imaging and evaluated their ability to identify resting-state networks. We adapted two resting-state methodologies from fMRI for the identification of resting-state networks using intraoperative RGB imaging. Measurements were performed in 3 patients who underwent resection of lesions adjacent to motor sites. The resting-state networks were compared to the identifications provided by RGB task-based imaging and electrical brain stimulation. Intraoperative RGB resting-state networks corresponded to RGB task-based imaging (DICE:0.55±0.29). Resting state procedures showed a strong correspondence between them (DICE:0.66±0.11) and with electrical brain stimulation. RGB imaging is a relevant technique for intraoperative resting-state networks identification. Intraoperative resting-state imaging has several advantages compared to functional task-based analyses: data acquisition is shorter, less complex, and less demanding for the patients, especially for those unable to perform the tasks.

Strategies to Improve Name Learning

2019 ◽  
Vol 24 (4) ◽  
pp. 349-358 ◽  
Author(s):  
Serge Brédart
Keyword(s):  
Older Adults ◽  
Learning Strategies ◽  
Mental Imagery ◽  
Brain Stimulation ◽  
Explicit Memory ◽  
Retrieval Practice ◽  
Electrical Brain Stimulation ◽  
Non Invasive ◽  
Spaced Retrieval ◽  
Neuroscience Research

Abstract. The following points emerge from the present review of strategies to improve the learning of proper names: (a) Face-name mnemonic techniques based on mental imagery have been shown to be efficient in laboratory settings in both young and older adults. Unfortunately, they are particularly effortful and require capacity for imagination, making them difficult to apply in a real conversational context. (b) Strategies based on spaced retrieval practice have been found to be efficient both in laboratory and more ecological settings, and both in young and older adults. (c) Techniques based on spaced retrieval practice appear to be more efficient than those based on mental imagery. (d) More recent research has proposed new perspectives, such as basing learning strategies on implicit, rather than explicit, memory processes such as hyper-binding. Finally, neuroscience research has started to investigate the possibility of using non-invasive electrical brain stimulation to improve name learning.

Homonymous Hemianopia

2019 ◽  
pp. 67-70
Author(s):  
Matthew J. Thurtell ◽  
Robert L. Tomsak
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Clinical Features ◽  
Primary Visual Cortex ◽  
Neurodegenerative Disorders ◽  
Field Testing ◽  
Diagnostic Evaluation ◽  
Homonymous Hemianopia ◽  
Visual Field Testing ◽  
Common Causes

Homonymous hemianopia is caused by unilateral lesions involving the retrochiasmal visual pathways or primary visual cortex. Common causes of homonymous hemianopia include stroke, tumor, and trauma. In this chapter, we begin by reviewing the clinical features that can help to localize the lesion and determine its cause. We next discuss the diagnostic evaluation of homonymous hemianopia, emphasizing the importance of formal visual field testing. We list causes of homonymous hemianopia that produce minimal or no abnormalities on neuroimaging, which include migraine, seizures, encephalopathies, and neurodegenerative disorders. Lastly, we discuss the implications of homonymous hemianopia for driving and strategies for rehabilitation.

scholarly journals Non-invasive brain stimulation effectiveness in anxiety disorder treatment: a meta-analysis on sham/behavior-controlled studies

2021 ◽  
Author(s):  
Alessandra Vergallito ◽  
Alessia Gallucci ◽  
Alberto Pisoni ◽  
Gabriele Caselli ◽  
Giovanni M. Ruggiero ◽  
...  
Keyword(s):  
Anxiety Disorders ◽  
Brain Stimulation ◽  
Clinical Symptoms ◽  
Meta Analysis ◽  
Anxiety And Depression ◽  
Non Invasive ◽  
The Past ◽  
Before And After ◽  
Disorder Treatment ◽  
Meta Analyses

AbstractOver the past decades, the possibility of using non-invasive brain stimulation (NIBS) to treat mental disorders received considerable attention. To date, no recommendation is available for anxiety disorders, suggesting that evidence is still limited. Here, we systematically revised the existing literature, and quantitively analyzed the effectiveness of transcranial magnetic stimulation and transcranial direct current stimulation in anxiety disorders treatment.Following PRISMA guidelines, three electronic databases were screened to the end of February 2020 to select English-written peer-reviewed articles, including a clinical anxiety sample, a NIBS technique, and a control condition. Overall, ten papers met the inclusion criteria.TheHedge g for scores at the specific and generic anxiety questionnaires before and after the treatment was computed as effect size and analyzed in two independent random-effects meta-analyses. Moreover, considering the well-known comorbidity between anxiety and depression, a third meta-analysis was run, analyzing depression scores’ outcomes. Albeit preliminary, our findings highlighted that real stimulation significantly reduced anxiety and depression scores compared to the control condition, suggesting that NIBS can alleviate clinical symptoms.

Sign in / Sign up

Export Citation Format

Share Document