1
|
Sharma G, Chitturi V, Sharma VK, Kathrotia R, Barde P, Parmar N, Sharma M, Singh RD. Innovative strategies for managing hallucinations by exploring effects of tDCS on source monitoring abilities. Sci Rep 2024; 14:16569. [PMID: 39019949 PMCID: PMC11254933 DOI: 10.1038/s41598-024-67279-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Accepted: 07/09/2024] [Indexed: 07/19/2024] Open
Abstract
This randomised, crossover, sham-controlled study explored the neural basis of source-monitoring, a crucial cognitive process implicated in schizophrenia. Left superior temporal gyrus (STG) and dorsolateral prefrontal cortex (DLPFC) were the key focus areas. Thirty participants without neurological or psychological disorders underwent offline sham and active tDCS sessions with specific electrode montage targeting the left STG and DLPFC. Source-monitoring tasks, reality monitoring (Hear-Imagine), internal source-monitoring (Say-Imagine), and external source monitoring (Virtual-Real) were administered. Paired t-test and estimation statistics was performed with Graphpad version 10.1.0. The Benjamini-Hochberg procedure was employed to control the false discovery rate in multiple hypothesis testing. A significant improvement in internal source monitoring tasks (p = 0.001, Cohen's d = 0.97) was observed, but reality monitoring tasks demonstrated moderate improvement (p = 0.02, Cohen's d = 0.44). The study provides insights into the neural mechanisms of source monitoring in healthy individuals and proposes tDCS as a therapeutic intervention, laying the foundation for future studies to refine tDCS protocols and develop individualized approaches to address source monitoring deficits in schizophrenia.
Collapse
Affiliation(s)
- Gaurav Sharma
- Department of Physiology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Vinay Chitturi
- Department of Physiology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Vivek Kumar Sharma
- Department of Physiology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Rajesh Kathrotia
- Department of Physiology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Pradip Barde
- Department of Physiology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Naresh Parmar
- Department of Physiology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Medhavi Sharma
- Department of Obstetrics and Gynaecology, All India Institute of Medical Sciences, Rajkot, Gujarat, India
| | - Ragini D Singh
- Department of Biochemistry, All India Institute of Medical Sciences, Rajkot, Gujarat, India.
| |
Collapse
|
2
|
Van Hoornweder S, Nuyts M, Frieske J, Verstraelen S, Meesen RLJ, Caulfield KA. Outcome measures for electric field modeling in tES and TMS: A systematic review and large-scale modeling study. Neuroimage 2023; 281:120379. [PMID: 37716590 PMCID: PMC11008458 DOI: 10.1016/j.neuroimage.2023.120379] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/18/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023] Open
Abstract
BACKGROUND Electric field (E-field) modeling is a potent tool to estimate the amount of transcranial magnetic and electrical stimulation (TMS and tES, respectively) that reaches the cortex and to address the variable behavioral effects observed in the field. However, outcome measures used to quantify E-fields vary considerably and a thorough comparison is missing. OBJECTIVES This two-part study aimed to examine the different outcome measures used to report on tES and TMS induced E-fields, including volume- and surface-level gray matter, region of interest (ROI), whole brain, geometrical, structural, and percentile-based approaches. The study aimed to guide future research in informed selection of appropriate outcome measures. METHODS Three electronic databases were searched for tES and/or TMS studies quantifying E-fields. The identified outcome measures were compared across volume- and surface-level E-field data in ten tES and TMS modalities targeting two common targets in 100 healthy individuals. RESULTS In the systematic review, we extracted 308 outcome measures from 202 studies that adopted either a gray matter volume-level (n = 197) or surface-level (n = 111) approach. Volume-level results focused on E-field magnitude, while surface-level data encompassed E-field magnitude (n = 64) and normal/tangential E-field components (n = 47). E-fields were extracted in ROIs, such as brain structures and shapes (spheres, hexahedra and cylinders), or the whole brain. Percentiles or mean values were mostly used to quantify E-fields. Our modeling study, which involved 1,000 E-field models and > 1,000,000 extracted E-field values, revealed that different outcome measures yielded distinct E-field values, analyzed different brain regions, and did not always exhibit strong correlations in the same within-subject E-field model. CONCLUSIONS Outcome measure selection significantly impacts the locations and intensities of extracted E-field data in both tES and TMS E-field models. The suitability of different outcome measures depends on the target region, TMS/tES modality, individual anatomy, the analyzed E-field component and the research question. To enhance the quality, rigor, and reproducibility in the E-field modeling domain, we suggest standard reporting practices across studies and provide four recommendations.
Collapse
Affiliation(s)
- Sybren Van Hoornweder
- REVAL - Rehabilitation Research Center, Faculty of Rehabilitation Sciences, University of Hasselt, Diepenbeek, Belgium.
| | - Marten Nuyts
- REVAL - Rehabilitation Research Center, Faculty of Rehabilitation Sciences, University of Hasselt, Diepenbeek, Belgium
| | - Joana Frieske
- REVAL - Rehabilitation Research Center, Faculty of Rehabilitation Sciences, University of Hasselt, Diepenbeek, Belgium; Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Stefanie Verstraelen
- REVAL - Rehabilitation Research Center, Faculty of Rehabilitation Sciences, University of Hasselt, Diepenbeek, Belgium
| | - Raf L J Meesen
- REVAL - Rehabilitation Research Center, Faculty of Rehabilitation Sciences, University of Hasselt, Diepenbeek, Belgium; Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
| | - Kevin A Caulfield
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States.
| |
Collapse
|
3
|
Van Hoornweder S, Nuyts M, Frieske J, Verstraelen S, Meesen RLJ, Caulfield KA. A Systematic Review and Large-Scale tES and TMS Electric Field Modeling Study Reveals How Outcome Measure Selection Alters Results in a Person- and Montage-Specific Manner. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.22.529540. [PMID: 36865243 PMCID: PMC9980068 DOI: 10.1101/2023.02.22.529540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Background Electric field (E-field) modeling is a potent tool to examine the cortical effects of transcranial magnetic and electrical stimulation (TMS and tES, respectively) and to address the high variability in efficacy observed in the literature. However, outcome measures used to report E-field magnitude vary considerably and have not yet been compared in detail. Objectives The goal of this two-part study, encompassing a systematic review and modeling experiment, was to provide an overview of the different outcome measures used to report the magnitude of tES and TMS E-fields, and to conduct a direct comparison of these measures across different stimulation montages. Methods Three electronic databases were searched for tES and/or TMS studies reporting E-field magnitude. We extracted and discussed outcome measures in studies meeting the inclusion criteria. Additionally, outcome measures were compared via models of four common tES and two TMS modalities in 100 healthy younger adults. Results In the systematic review, we included 118 studies using 151 outcome measures related to E-field magnitude. Structural and spherical regions of interest (ROI) analyses and percentile-based whole-brain analyses were used most often. In the modeling analyses, we found that there was an average of only 6% overlap between ROI and percentile-based whole-brain analyses in the investigated volumes within the same person. The overlap between ROI and whole-brain percentiles was montage- and person-specific, with more focal montages such as 4Ã-1 and APPS-tES, and figure-of-eight TMS showing up to 73%, 60%, and 52% overlap between ROI and percentile approaches respectively. However, even in these cases, 27% or more of the analyzed volume still differed between outcome measures in every analyses. Conclusions The choice of outcome measures meaningfully alters the interpretation of tES and TMS E-field models. Well-considered outcome measure selection is imperative for accurate interpretation of results, valid between-study comparisons, and depends on stimulation focality and study goals. We formulated four recommendations to increase the quality and rigor of E-field modeling outcome measures. With these data and recommendations, we hope to guide future studies towards informed outcome measure selection, and improve the comparability of studies.
Collapse
|
4
|
Mondino M, Janin D, Galvao F, Brunelin J. High-Frequency Transcranial Random Noise Stimulation for Auditory Hallucinations of Schizophrenia: A Case Series. Biomedicines 2022; 10:2698. [PMID: 36359217 PMCID: PMC9687535 DOI: 10.3390/biomedicines10112698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 09/26/2022] [Accepted: 10/18/2022] [Indexed: 09/19/2023] Open
Abstract
Transcranial electrical stimulation has been proposed as a noninvasive therapeutic approach for reducing treatment-resistant symptoms of schizophrenia-in particular, auditory hallucinations. However, the high variability observed in the clinical response leaves much room to optimize the stimulation parameters and strengthen its benefits. We proposed to investigate the effects of high-frequency transcranial random noise stimulation (hf-tRNS), which is supposed to induce larger effects than conventional direct current stimulation. Here, we present an initial case series of ten patients with schizophrenia who underwent 10 sessions of 20 min hf-tRNS (2 mA, 100-500 Hz, 1 mA offset), with the anode placed over the left dorsolateral prefrontal cortex and the cathode over the left temporoparietal junction. Patients showed a significant reduction in auditory hallucinations after the hf-tRNS sessions (-36.1 +/- 21.8%, p = 0.0059). In this preliminary, open-label study conducted in ten patients with treatment-resistant symptoms of schizophrenia, frontotemporal hf-tRNS was shown to induce a substantial improvement in auditory hallucinations. Additional sham-controlled studies are needed to further evaluate hf-tRNS as a treatment for schizophrenia.
Collapse
Affiliation(s)
- Marine Mondino
- Pôle Est, Centre Hospitalier Le Vinatier, F-69500 Bron, France
- PSYR2 Team, Lyon Neuroscience Research Center, INSERM U1028, CNRS UMR5292, F-69000 Lyon, France
- University Lyon 1, F-69100 Villeurbanne, France
| | - Delphine Janin
- Pôle Est, Centre Hospitalier Le Vinatier, F-69500 Bron, France
- PSYR2 Team, Lyon Neuroscience Research Center, INSERM U1028, CNRS UMR5292, F-69000 Lyon, France
- University Lyon 1, F-69100 Villeurbanne, France
| | - Filipe Galvao
- Pôle Est, Centre Hospitalier Le Vinatier, F-69500 Bron, France
| | - Jérôme Brunelin
- Pôle Est, Centre Hospitalier Le Vinatier, F-69500 Bron, France
- PSYR2 Team, Lyon Neuroscience Research Center, INSERM U1028, CNRS UMR5292, F-69000 Lyon, France
- University Lyon 1, F-69100 Villeurbanne, France
| |
Collapse
|
5
|
Abstract
Although the population-level preference for the use of the right hand is the clearest example of behavioral lateralization, it represents only the best-known instance of a variety of functional asymmetries observable in humans. What is interesting is that many of such asymmetries emerge during the processing of social stimuli, as often occurs in the case of human bodies, faces and voices. In the present paper, after reviewing previous literature about human functional asymmetries for social and emotional stimuli, we suggest some possible links among them and stress the necessity of a comprehensive account (in both ontogenetic and phylogenetic terms) for these not yet fully explained phenomena. In particular, we propose that the advantages of lateralization for emotion processing should be considered in light of previous suggestions that (i) functional hemispheric specialization enhances cognitive capacity and efficiency, and (ii) the alignment (at the population level) of the direction of behavioral asymmetries emerges, under social pressures, as an evolutionary stable strategy.
Collapse
|
6
|
Effect of transcranial direct current stimulation on in-vivo assessed neuro-metabolites through magnetic resonance spectroscopy: a systematic review. Acta Neuropsychiatr 2021; 33:242-253. [PMID: 33926587 DOI: 10.1017/neu.2021.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVES Previous studies have examined the effect of transcranial direct current stimulation (tDCS) on the in-vivo concentrations of neuro-metabolites assessed through magnetic resonance spectroscopy (MRS) in neurological and psychiatry disorders. This review aims to systematically evaluate the data on the effect of tDCS on MRS findings and thereby attempt to understand the potential mechanism of tDCS on neuro-metabolites. METHODS The relevant literature was obtained through PubMed and cross-reference (search till June 2020). Thirty-four studies were reviewed, of which 22 reported results from healthy controls and 12 were from patients with neurological and psychiatric disorders. RESULTS The evidence converges to highlight that tDCS modulates the neuro-metabolite levels at the site of stimulation, which, in turn, translates into alterations in the behavioural outcome. It also shows that the baseline level of these neuro-metabolites can, to a certain extent, predict the outcome after tDCS. However, even though tDCS has shown promising effects in alleviating symptoms of various psychiatric disorders, there are limited studies that have reported the effect of tDCS on neuro-metabolite levels. CONCLUSIONS There is a compelling need for more systematic studies examining patients with psychiatric/neurological disorders with larger samples and harmonised tDCS protocols. More studies will potentially help us to understand the tDCS mechanism of action pertinent to neuro-metabolite levels modulation. Further, studies should be conducted in psychiatric patients to understand the neurological changes in this population and potentially unravel the neuro-metabolite × tDCS interaction effect that can be translated into individualised treatment.
Collapse
|
7
|
Kusztrits I, Marquardt L, Hugdahl K, Hirnstein M. Transcranial direct current stimulation (tDCS) enhances internal source monitoring abilities in healthy participants. PLoS One 2021; 16:e0257010. [PMID: 34529676 PMCID: PMC8445448 DOI: 10.1371/journal.pone.0257010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 08/20/2021] [Indexed: 11/18/2022] Open
Abstract
Source monitoring refers to the ability to identify the origin of a memory, for example, whether you remember saying something or thinking about it, and confusions of these sources have been associated with the experience of auditory verbal hallucinations (AVHs). Both AVHs and source confusions are reported to originate from dysfunctional brain activations in the prefrontal cortex (PFC) and the superior temporal gyrus (STG); specifically, it is assumed that a hypoactive PFC and a hyperactive STG gives rise to AVHs and source confusions. We set out to test this assumption by trying to mimic this hypertemporal/hypofrontal model in healthy individuals with transcranial direct current stimulation (tDCS): the inhibitory cathode was placed over the left PFC and the excitatory anode over the left dorsolateral STG. Participants completed a reality monitoring task (distinguishing between external and internal memory sources) and an internal source monitoring task (distinguishing between two or more internal memory sources) in two separate experiments (offline vs. online tDCS). In the offline experiment (n = 34), both source monitoring tasks were completed after tDCS stimulation, and in the online experiment (n = 27) source monitoring tasks were completed while simultaneously being stimulated with tDCS. We found that internal source monitoring abilities were significantly enhanced during active online tDCS, while reality monitoring abilities were unaffected by stimulation in both experiments. We speculate, based on combining the present findings with previous studies, that there might be different brain areas involved in reality and internal source monitoring. While internal source monitoring seems to involve speech production areas, specifically Broca’s area, as suggested in the present study, reality monitoring seems to rely more on the STG and DLPFC, as shown in other studies of the field.
Collapse
Affiliation(s)
- Isabella Kusztrits
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway
- NORMENT Norwegian Centre for Mental Health Disorders Research, University of Bergen and Haukeland University Hospital, Bergen, Norway
- * E-mail:
| | - Lynn Marquardt
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway
- NORMENT Norwegian Centre for Mental Health Disorders Research, University of Bergen and Haukeland University Hospital, Bergen, Norway
| | - Kenneth Hugdahl
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway
- NORMENT Norwegian Centre for Mental Health Disorders Research, University of Bergen and Haukeland University Hospital, Bergen, Norway
- Department of Radiology, Haukeland University Hospital, Bergen, Norway
- Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Marco Hirnstein
- Department of Biological and Medical Psychology, University of Bergen, Bergen, Norway
- NORMENT Norwegian Centre for Mental Health Disorders Research, University of Bergen and Haukeland University Hospital, Bergen, Norway
| |
Collapse
|
8
|
Zaehle T. Frontal Transcranial Direct Current Stimulation as a Potential Treatment of Parkinson's Disease-Related Fatigue. Brain Sci 2021; 11:brainsci11040467. [PMID: 33917684 PMCID: PMC8068015 DOI: 10.3390/brainsci11040467] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 03/22/2021] [Accepted: 03/30/2021] [Indexed: 12/28/2022] Open
Abstract
In contrast to motor symptoms, non-motor symptoms in Parkinson’s disease (PD) are often poorly recognized and inadequately treated. Fatigue is one of the most common non-motor symptoms in PD and affects a broad range of everyday activities, causes disability, and substantially reduces the quality of life. It occurs at every stage of PD, and once present, it often persists and worsens over time. PD patients attending the 2013 World Parkinson Congress voted fatigue as the leading symptom in need of further research. However, despite its clinical significance, little progress has been made in understanding the causes of Parkinson’s disease-related fatigue (PDRF) and developing effective treatment options, which argues strongly for a greater effort. Transcranial direct current stimulation (tDCS) is a technique to non-invasively modulate cortical excitability by delivering low electrical currents to the cerebral cortex. In the past, it has been consistently evidenced that tDCS has the ability to induce neuromodulatory changes in the motor, sensory, and cognitive domains. Importantly, recent data present tDCS over the frontal cortex as an effective therapeutic option to treat fatigue in patients suffering from multiple sclerosis (MS). The current opinion paper reviews recent data on PDRF and the application of tDCS for the treatment of fatigue in neuropsychiatric disorders to further develop an idea of using frontal anodal tDCS as a potential therapeutic strategy to alleviate one of the most common and severe non-motor symptoms of PD.
Collapse
Affiliation(s)
- Tino Zaehle
- Department of Neurology, Otto-von-Guericke-University Magdeburg, 39120 Magdeburg, Germany;
- Center for Behavioral Brain Sciences (CBBS), 39106 Magdeburg, Germany
| |
Collapse
|