51
|
Steinmann I, Williams KA, Wilke M, Antal A. Detection of Transcranial Alternating Current Stimulation Aftereffects Is Improved by Considering the Individual Electric Field Strength and Self-Rated Sleepiness. Front Neurosci 2022; 16:870758. [PMID: 35833087 PMCID: PMC9272587 DOI: 10.3389/fnins.2022.870758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 05/04/2022] [Indexed: 11/13/2022] Open
Abstract
Non-invasive electrical stimulation methods, such as transcranial alternating current stimulation (tACS), are increasingly used in human neuroscience research and offer potential new avenues to treat neurological and psychiatric disorders. However, their often variable effects have also raised concerns in the scientific and clinical communities. This study aims to investigate the influence of subject-specific factors on the alpha tACS-induced aftereffect on the alpha amplitude (measured with electroencephalography, EEG) as well as on the connectivity strength between nodes of the default mode network (DMN) [measured with functional magnetic resonance imaging (fMRI)]. As subject-specific factors we considered the individual electrical field (EFIELD) strength at target regions in the brain, the frequency mismatch between applied stimulation and individual alpha frequency (IAF) and as a covariate, subject’s changes in mental state, i.e., sleepiness. Eighteen subjects participated in a tACS and a sham session conducted on different days. Each session consisted of three runs (pre/stimulation/). tACS was applied during the second run at each subject’s individual alpha frequency (IAF), applying 1 mA peak-to-peak intensity for 7 min, using an occipital bihemispheric montage. In every run, subjects watched a video designed to increase in-scanner compliance. To investigate the aftereffect of tACS on EEG alpha amplitude and on DMN connectivity strength, EEG data were recorded simultaneously with fMRI data. Self-rated sleepiness was documented using a questionnaire. Conventional statistics (ANOVA) did not show a significant aftereffect of tACS on the alpha amplitude compared to sham stimulation. Including individual EFIELD strengths and self-rated sleepiness scores in a multiple linear regression model, significant tACS-induced aftereffects were observed. However, the subject-wise mismatch between tACS frequency and IAF had no contribution to our model. Neither standard nor extended statistical methods confirmed a tACS-induced aftereffect on DMN functional connectivity. Our results show that it is possible and necessary to disentangle alpha amplitude changes due to intrinsic mechanisms and to external manipulation using tACS on the alpha amplitude that might otherwise be overlooked. Our results suggest that EFIELD is really the most significant factor that explains the alpha amplitude modulation during a tACS session. This knowledge helps to understand the variability of the tACS-induced aftereffects.
Collapse
Affiliation(s)
- Iris Steinmann
- Department of Cognitive Neurology, University Medical Center Göttingen, Göttingen, Germany
- *Correspondence: Iris Steinmann,
| | - Kathleen A. Williams
- Department of Cognitive Neurology, University Medical Center Göttingen, Göttingen, Germany
- Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Melanie Wilke
- Department of Cognitive Neurology, University Medical Center Göttingen, Göttingen, Germany
- German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Andrea Antal
- Department of Neurology, University Medical Center Göttingen, Göttingen, Germany
- Andrea Antal,
| |
Collapse
|
52
|
Mussigmann T, Bardel B, Lefaucheur JP. Resting-state electroencephalography (EEG) biomarkers of chronic neuropathic pain. A systematic review. Neuroimage 2022; 258:119351. [PMID: 35659993 DOI: 10.1016/j.neuroimage.2022.119351] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/09/2022] [Accepted: 05/31/2022] [Indexed: 10/18/2022] Open
Abstract
Diagnosis and management of chronic neuropathic pain are challenging, leading to current efforts to characterize 'objective' biomarkers of pain using imaging or neurophysiological techniques, such as electroencephalography (EEG). A systematic literature review was conducted in PubMed-Medline and Web-of-Science until October 2021 to identify EEG biomarkers of chronic neuropathic pain in humans. The risk of bias was assessed by the Newcastle-Ottawa-Scale. Experimental, provoked, or chronic non-neuropathic pain studies were excluded. We identified 14 studies, in which resting-state EEG spectral analysis was compared between patients with pain related to a neurological disease and patients with the same disease but without pain or healthy controls. From these heterogeneous exploratory studies, some conclusions can be drawn, even if they must be weighted by the fact that confounding factors, such as medication and association with anxio-depressive disorders, are generally not taken into account. Overall, EEG signal power was increased in the θ band (4-7Hz) and possibly in the high-β band (20-30Hz), but decreased in the high-α-low-β band (10-20Hz) in the presence of ongoing neuropathic pain, while increased γ band oscillations were not evidenced, unlike in experimental pain. Consequently, the dominant peak frequency was decreased in the θ-α band and increased in the whole-β band in neuropathic pain patients. Disappointingly, pain intensity correlated with various EEG changes across studies, with no consistent trend. This review also discusses the location of regional pain-related EEG changes in the pain connectome, as the perspectives offered by advanced techniques of EEG signal analysis (source location, connectivity, or classification methods based on artificial intelligence). The biomarkers provided by resting-state EEG are of particular interest for optimizing the treatment of chronic neuropathic pain by neuromodulation techniques, such as transcranial alternating current stimulation or neurofeedback procedures.
Collapse
Affiliation(s)
- Thibaut Mussigmann
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France
| | - Benjamin Bardel
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France
| | - Jean-Pascal Lefaucheur
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France.
| |
Collapse
|
53
|
Xiong HY, Zheng JJ, Wang XQ. Non-invasive Brain Stimulation for Chronic Pain: State of the Art and Future Directions. Front Mol Neurosci 2022; 15:888716. [PMID: 35694444 PMCID: PMC9179147 DOI: 10.3389/fnmol.2022.888716] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 04/27/2022] [Indexed: 12/13/2022] Open
Abstract
As a technique that can guide brain plasticity, non-invasive brain stimulation (NIBS) has the potential to improve the treatment of chronic pain (CP) because it can interfere with ongoing brain neural activity to regulate specific neural networks related to pain management. Treatments of CP with various forms of NIBS, such as repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS), using new parameters of stimulation have achieved encouraging results. Evidence of moderate quality indicates that high-frequency rTMS of the primary motor cortex has a clear effect on neuropathic pain (NP) and fibromyalgia. However, evidence on its effectiveness regarding pain relief in other CP conditions is conflicting. Concerning tDCS, evidence of low quality supports its benefit for CP treatment. However, evidence suggesting that it exerts a small treatment effect on NP and headaches is also conflicting. In this paper, we describe the underlying principles behind these commonly used stimulation techniques; and summarize the results of randomized controlled trials, systematic reviews, and meta-analyses. Future research should focus on a better evaluation of the short-term and long-term effectiveness of all NIBS techniques and whether they decrease healthcare use, as well as on the refinement of selection criteria.
Collapse
Affiliation(s)
- Huan-Yu Xiong
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China
| | | | - Xue-Qiang Wang
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China
- Department of Rehabilitation Medicine, Shanghai Shangti Orthopaedic Hospital, Shanghai, China
| |
Collapse
|
54
|
Translational Approaches to Influence Sleep and Arousal. Brain Res Bull 2022; 185:140-161. [PMID: 35550156 PMCID: PMC9554922 DOI: 10.1016/j.brainresbull.2022.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/27/2022] [Accepted: 05/03/2022] [Indexed: 12/16/2022]
Abstract
Sleep disorders are widespread in society and are prevalent in military personnel and in Veterans. Disturbances of sleep and arousal mechanisms are common in neuropsychiatric disorders such as schizophrenia, post-traumatic stress disorder, anxiety and affective disorders, traumatic brain injury, dementia, and substance use disorders. Sleep disturbances exacerbate suicidal ideation, a major concern for Veterans and in the general population. These disturbances impair quality of life, affect interpersonal relationships, reduce work productivity, exacerbate clinical features of other disorders, and impair recovery. Thus, approaches to improve sleep and modulate arousal are needed. Basic science research on the brain circuitry controlling sleep and arousal led to the recent approval of new drugs targeting the orexin/hypocretin and histamine systems, complementing existing drugs which affect GABAA receptors and monoaminergic systems. Non-invasive brain stimulation techniques to modulate sleep and arousal are safe and show potential but require further development to be widely applicable. Invasive viral vector and deep brain stimulation approaches are also in their infancy but may be used to modulate sleep and arousal in severe neurological and psychiatric conditions. Behavioral, pharmacological, non-invasive brain stimulation and cell-specific invasive approaches covered here suggest the potential to selectively influence arousal, sleep initiation, sleep maintenance or sleep-stage specific phenomena such as sleep spindles or slow wave activity. These manipulations can positively impact the treatment of a wide range of neurological and psychiatric disorders by promoting the restorative effects of sleep on memory consolidation, clearance of toxic metabolites, metabolism, and immune function and by decreasing hyperarousal.
Collapse
|
55
|
Sadeghihassanabadi F, Misselhorn J, Gerloff C, Zittel-Dirks S. Optimizing the Montage for Cerebellar Transcranial Alternating Current Stimulation (tACS): a Combined Computational and Experimental Study. J Neural Eng 2022; 19. [PMID: 35421852 DOI: 10.1088/1741-2552/ac676f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 04/13/2022] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The application of cerebellar transcranial alternating current stimulation (tACS) is limited by the absence of commonly agreed montages and also the presence of unpleasant side effects. We aimed to find the most effective cerebellar tACS montage with minimum side effects (skin sensations and phosphenes). APPROACH We first simulated cerebellar tACS with five montages (return electrode on forehead, buccinator, jaw, and neck positions, additionally focal montage with high-definition ring electrodes) to compare induced cerebellar current, then stimulated healthy participants and evaluated side effects for different montages and varying stimulation frequencies. MAIN RESULTS The simulation revealed a descending order of current density in the cerebellum from forehead to buccinator, jaw, neck and ring montage respectively. Montages inducing higher current intensity in the eyeballs during the simulation resulted in stronger and broader phosphenes during tACS sessions. Strong co-stimulation of the brainstem was observed for the neck. Skin sensations did not differ between montages or frequencies. We propose the jaw montage as an optimal choice for maximizing cerebellar stimulation while minimizing unwanted side effects. SIGNIFICANCE These findings contribute to adopting a standard cerebellar tACS protocol. The combination of computational modelling and experimental data offers improved experimental control, safety, effectiveness, and reproducibility to all brain stimulation practices.
Collapse
Affiliation(s)
- Fatemeh Sadeghihassanabadi
- Klinik und Poliklinik für Neurologie, University Medical Center Hamburg-Eppendorf Head and Neurocenter, Martinistraße 52, Hamburg, Hamburg, 20246, GERMANY
| | - Jonas Misselhorn
- Institut für Neurophysiologie und Pathophysiologie , Universitätsklinikum Hamburg-Eppendorf Zentrum für Experimentelle Medizin, Martinistraße 52, Hamburg, Hamburg, 20246, GERMANY
| | - Christian Gerloff
- Department of Neurology, University Medical Center, Universitatsklinikum Hamburg-Eppendorf, Martinistraße 52, Hamburg, Hamburg, 20246, GERMANY
| | - Simone Zittel-Dirks
- Klinik und Poliklinik für Neurologie, University Medical Center Hamburg-Eppendorf Head and Neurocenter, Martinistraße 52, Hamburg, Hamburg, 20246, GERMANY
| |
Collapse
|
56
|
Starosta M, Cichoń N, Saluk-Bijak J, Miller E. Benefits from Repetitive Transcranial Magnetic Stimulation in Post-Stroke Rehabilitation. J Clin Med 2022; 11:jcm11082149. [PMID: 35456245 PMCID: PMC9030945 DOI: 10.3390/jcm11082149] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 04/11/2022] [Indexed: 02/04/2023] Open
Abstract
Stroke is an acute neurovascular central nervous system (CNS) injury and one of the main causes of long-term disability and mortality. Post-stroke rehabilitation as part of recovery is focused on relearning lost skills and regaining independence as much as possible. Many novel strategies in neurorehabilitation have been introduced. This review focuses on current evidence of the effectiveness of repetitive transcranial magnetic stimulation (rTMS), a noninvasive brain stimulation (NIBS), in post-stroke rehabilitation. Moreover, we present the effects of specific interventions, such as low-frequency or high-frequency rTMS therapy, on motor function, cognitive function, depression, and aphasia in post-stroke patients. Collected data suggest that high-frequency stimulation (5 Hz and beyond) produces an increase in cortical excitability, whereas low-frequency stimulation (≤1 Hz) decreases cortical excitability. Accumulated data suggest that rTMS is safe and can be used to modulate cortical excitability, which may improve overall performance. Side effects such as tingling sensation on the skin of the skull or headache are possible. Serious side effects such as epileptic seizures can be avoided by adhering to international safety guidelines. We reviewed clinical studies that present promising results in general recovery and stimulating neuroplasticity. This article is an overview of the current rTMS state of knowledge related to benefits in stroke, as well as its cellular and molecular mechanisms. In the stroke rehabilitation literature, there is a key methodological problem of creating double-blinding studies, which are very often impossible to conduct.
Collapse
Affiliation(s)
- Michał Starosta
- Department of Neurological Rehabilitation, Medical University of Lodz, Milionowa 14, 93-113 Lodz, Poland;
- Correspondence:
| | - Natalia Cichoń
- Biohazard Prevention Centre, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland;
| | - Joanna Saluk-Bijak
- Department of General Biochemistry, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland;
| | - Elżbieta Miller
- Department of Neurological Rehabilitation, Medical University of Lodz, Milionowa 14, 93-113 Lodz, Poland;
| |
Collapse
|
57
|
Palm U, Baumgartner C, Hoffmann L, Padberg F, Hasan A, Strube W, Papazova I. Single session gamma transcranial alternating stimulation does not modulate working memory in depressed patients and healthy controls. Neurophysiol Clin 2022; 52:128-136. [PMID: 35351388 DOI: 10.1016/j.neucli.2022.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVES Gamma transcranial alternating current stimulation (gamma tACS) is considered a non-invasive brain stimulation technique for modulation of cognitive performance and for treatment of psychiatric disorders. There is heterogeneous data on its effectiveness in improving working memory. METHODS In this randomized crossover study, we tested 22 patients with major depression and 21 healthy volunteers who received 20 min of active and sham 40 Hz gamma tACS over bilateral dorsolateral prefrontal cortex during a computerized n-back task in a cross-over design. RESULTS We showed no improvement in reaction time and accuracy of working memory during active or sham stimulation in both groups, and no interaction between cognitive load and stimulation conditions. CONCLUSION The present study suggests that a single session of gamma tACS does not affect cognition in depression. However, the bilateral electrode montage and learning or ceiling effects may have affected results. Overall, this study is in line with the heterogeneous results of previous gamma tACS studies, emphasizing that methodologies and study designs should be harmonized.
Collapse
Affiliation(s)
- Ulrich Palm
- Department of Psychiatry and Psychotherapy, Hospital of the University of Munich, Munich, Germany; Medical Park Chiemseeblick, Bernau-Felden, Germany.
| | - Carolin Baumgartner
- Department of Psychiatry and Psychotherapy, Hospital of the University of Munich, Munich, Germany
| | - Lina Hoffmann
- Department of Psychiatry and Psychotherapy, Hospital of the University of Munich, Munich, Germany
| | - Frank Padberg
- Department of Psychiatry and Psychotherapy, Hospital of the University of Munich, Munich, Germany
| | - Alkomiet Hasan
- Department of Psychiatry and Psychotherapy, Hospital of the University of Munich, Munich, Germany; Psychiatry and Psychotherapy, Faculty of Medicine, University of Augsburg, Bezirkskrankenhaus Augsburg, Augsburg, Germany
| | - Wolfgang Strube
- Department of Psychiatry and Psychotherapy, Hospital of the University of Munich, Munich, Germany; Psychiatry and Psychotherapy, Faculty of Medicine, University of Augsburg, Bezirkskrankenhaus Augsburg, Augsburg, Germany
| | - Irina Papazova
- Department of Psychiatry and Psychotherapy, Hospital of the University of Munich, Munich, Germany; Psychiatry and Psychotherapy, Faculty of Medicine, University of Augsburg, Bezirkskrankenhaus Augsburg, Augsburg, Germany
| |
Collapse
|
58
|
Double-blind randomized N-of-1 trial of transcranial alternating current stimulation for mal de débarquement syndrome. PLoS One 2022; 17:e0263558. [PMID: 35120184 PMCID: PMC8815977 DOI: 10.1371/journal.pone.0263558] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 01/13/2022] [Indexed: 11/24/2022] Open
Abstract
Background Mal de Débarquement Syndrome (MdDS) is a medically refractory neurotological disorder characterized by persistent oscillating vertigo that follows a period of entrainment to oscillating motion such as experienced during sea or air travel. Fronto-occipital hypersynchrony may correlate with MdDS symptom severity. Materials and methods Individuals with treatment refractory MdDS lasting at least 6 months received single administrations of three fronto-occipital transcranial alternating current stimulation (tACS) protocols in an “n-of-1” double-blind randomized design: alpha frequency anti-phase, alpha-frequency in-phase, and gamma frequency control. Baseline assessments were made on Day 1. The treatment protocol that led to the most acute reduction in symptoms during a test session on Day 2 was administered for 10–12 stacked sessions given on Days 3 through 5 (20-minutes at 2-4mA). Pre to post symptom changes were assessed on Day 1 and Day 5. Participants who could clearly choose a preferred protocol on Day 2 did better on Day 5 than those who could not make a short-term determination on Day 2 and either chose a protocol based on minimized side effects or were randomized to one of the three protocols. In addition, weekly symptom assessments were made for four baseline and seven post stimulation points for the Dizziness Handicap Inventory (DHI), MdDS Balance Rating Scale (MBRS), and Hospital Anxiety and Depression Scale (HADS). Results Of 24 participants, 13 chose anti-phase, 7 chose in-phase, and 4 chose control stimulation. Compared to baseline, 10/24 completers noted ≥ 25% reduction, 5/24 ≥50% reduction, and 2/24 ≥75% reduction in oscillating vertigo intensity from Day 1 to Day 5. Stimulating at a frequency slightly higher than the individual alpha frequency (IAF) was better than stimulating at exactly the IAF, and slightly better than stimulating with a strategy of standardized stimulation at 10Hz. A one-way repeated measures ANOVA of weekly DHI, MBRS, and HADS measurements showed significant reductions immediately after treatment with improvement increasing through post-treatment week 6. Conclusion Fronto-occipital tACS may be effective in reducing the oscillating vertigo of MdDS and serve as a portable neuromodulation alternative for longer-term treatment. Stimulation frequency relative to the IAF may be important in determining the optimum treatment protocol [ClinicalTrials.gov study NCT02540616. https://clinicaltrials.gov/ct2/show/NCT02540616].
Collapse
|
59
|
Potential role for peripheral nerve stimulation on learning and long-term memory: A comparison of alternating and direct current stimulations. Brain Stimul 2022; 15:536-545. [DOI: 10.1016/j.brs.2022.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 02/22/2022] [Accepted: 03/04/2022] [Indexed: 11/20/2022] Open
|
60
|
Al Qasem W, Abubaker M, Kvašňák E. Working Memory and Transcranial-Alternating Current Stimulation-State of the Art: Findings, Missing, and Challenges. Front Psychol 2022; 13:822545. [PMID: 35237214 PMCID: PMC8882605 DOI: 10.3389/fpsyg.2022.822545] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 01/19/2022] [Indexed: 12/06/2022] Open
Abstract
Working memory (WM) is a cognitive process that involves maintaining and manipulating information for a short period of time. WM is central to many cognitive processes and declines rapidly with age. Deficits in WM are seen in older adults and in patients with dementia, schizophrenia, major depression, mild cognitive impairment, Alzheimer's disease, etc. The frontal, parietal, and occipital cortices are significantly involved in WM processing and all brain oscillations are implicated in tackling WM tasks, particularly theta and gamma bands. The theta/gamma neural code hypothesis assumes that retained memory items are recorded via theta-nested gamma cycles. Neuronal oscillations can be manipulated by sensory, invasive- and non-invasive brain stimulations. Transcranial alternating-current stimulation (tACS) and repetitive transcranial magnetic stimulation (rTMS) are frequency-tuned non-invasive brain stimulation (NIBS) techniques that have been used to entrain endogenous oscillations in a frequency-specific manner. Compared to rTMS, tACS demonstrates superior cost, tolerability, portability, and safety profile, making it an attractive potential tool for improving cognitive performance. Although cognitive research with tACS is still in its infancy compared to rTMS, a number of studies have shown a promising WM enhancement effect, especially in the elderly and patients with cognitive deficits. This review focuses on the various methods and outcomes of tACS on WM in healthy and unhealthy human adults and highlights the established findings, unknowns, challenges, and perspectives important for translating laboratory tACS into realistic clinical settings. This will allow researchers to identify gaps in the literature and develop frequency-tuned tACS protocols with promising safety and efficacy outcomes. Therefore, research efforts in this direction should help to consider frequency-tuned tACS as a non-pharmacological tool of cognitive rehabilitation in physiological aging and patients with cognitive deficits.
Collapse
Affiliation(s)
- Wiam Al Qasem
- Department of Medical Biophysics and Medical Informatics, Third Faculty of Medicine, Charles University in Prague, Praha, Czechia
| | | | | |
Collapse
|
61
|
Suzuki M, Tanaka S, Gomez-Tames J, Okabe T, Cho K, Iso N, Hirata A. Nonequivalent After-Effects of Alternating Current Stimulation on Motor Cortex Oscillation and Inhibition: Simulation and Experimental Study. Brain Sci 2022; 12:brainsci12020195. [PMID: 35203958 PMCID: PMC8870173 DOI: 10.3390/brainsci12020195] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/28/2022] [Accepted: 01/28/2022] [Indexed: 02/01/2023] Open
Abstract
The effects of transcranial alternating current stimulation (tACS) frequency on brain oscillations and cortical excitability are still controversial. Therefore, this study investigated how different tACS frequencies differentially modulate cortical oscillation and inhibition. To do so, we first determined the optimal positioning of tACS electrodes through an electric field simulation constructed from magnetic resonance images. Seven electrode configurations were tested on the electric field of the precentral gyrus (hand motor area). We determined that the Cz-CP1 configuration was optimal, as it resulted in higher electric field values and minimized the intra-individual differences in the electric field. Therefore, tACS was delivered to the hand motor area through this arrangement at a fixed frequency of 10 Hz (alpha-tACS) or 20 Hz (beta-tACS) with a peak-to-peak amplitude of 0.6 mA for 20 min. We found that alpha- and beta-tACS resulted in larger alpha and beta oscillations, respectively, compared with the oscillations observed after sham-tACS. In addition, alpha- and beta-tACS decreased the amplitudes of conditioned motor evoked potentials and increased alpha and beta activity, respectively. Correspondingly, alpha- and beta-tACSs enhanced cortical inhibition. These results show that tACS frequency differentially affects motor cortex oscillation and inhibition.
Collapse
Affiliation(s)
- Makoto Suzuki
- Faculty of Health Sciences, Tokyo Kasei University, 2-15-1 Inariyama, Sayama 350-1398, Saitama, Japan; (T.O.); (K.C.); (N.I.)
- Correspondence: ; Tel.: +81-42-955-6074
| | - Satoshi Tanaka
- Laboratory of Psychology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-ku, Hamamatsu 431-3192, Shizuoka, Japan;
| | - Jose Gomez-Tames
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Aichi, Japan; (J.G.-T.); (A.H.)
- Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Aichi, Japan
| | - Takuhiro Okabe
- Faculty of Health Sciences, Tokyo Kasei University, 2-15-1 Inariyama, Sayama 350-1398, Saitama, Japan; (T.O.); (K.C.); (N.I.)
| | - Kilchoon Cho
- Faculty of Health Sciences, Tokyo Kasei University, 2-15-1 Inariyama, Sayama 350-1398, Saitama, Japan; (T.O.); (K.C.); (N.I.)
| | - Naoki Iso
- Faculty of Health Sciences, Tokyo Kasei University, 2-15-1 Inariyama, Sayama 350-1398, Saitama, Japan; (T.O.); (K.C.); (N.I.)
| | - Akimasa Hirata
- Department of Electrical and Mechanical Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Aichi, Japan; (J.G.-T.); (A.H.)
- Center of Biomedical Physics and Information Technology, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Aichi, Japan
| |
Collapse
|
62
|
Amthor FR, Strang CE. Effects of tACS-Like Electrical Stimulation on Correlated Firing of Retinal Ganglion Cells: Part III. Eye Brain 2022; 14:1-15. [PMID: 35046742 PMCID: PMC8763268 DOI: 10.2147/eb.s313161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 11/30/2021] [Indexed: 02/02/2023] Open
Abstract
Purpose Transcranial alternating current stimulation (tACS) is a stimulation protocol used for learning enhancement and mitigation of cognitive dysfunction. Correlated firing has been postulated to be a meta-code that links neuronal spike responses associated with a single entity and may be an important component of high-level cognitive functions. Thus, changes in the covariance firing structure of CNS neurons such as retinal ganglion cells are one potential mechanism by which tACS can exert its effects. Materials and Methods We used microelectrode arrays to record light-evoked spike responses of 24 retinal ganglion cells in 7 rabbit eyecup preparations and analyzed the covariance between 30 pairs of neighboring retinal ganglion cells before, during, and after 10-minute application of alternating currents of 1 microampere at 10 or 20 Hz. Results tACS stimulation significantly changed the covariance structure of correlated firing in 60% of simultaneously recorded retinal ganglion cells. Application of tACS in the retinal preparation increased cross-covariance in 26% of cell pairs, an effect usually associated with increased light-evoked ganglion cell firing. tACS associated decreases in cross-covariance occurred in 37% of cell pairs. Increased covariance was more common in response to the first, 10-minute application of tACS in isolated retina preparation. Changes in covariance were rare after repeated stimulation, and more likely to result in decreased covariance. Conclusion Retinal ganglion cell correlated firing is modulated by 1 microampere tACS currents showing that electrical stimulation can significantly and persistently change the structure of the correlated firing of simultaneously recorded rabbit retinal ganglion cells.
Collapse
Affiliation(s)
- Franklin R Amthor
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| | - Christianne E Strang
- Department of Psychology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
| |
Collapse
|
63
|
Tzvi E, Alizadeh J, Schubert C, Classen J. Classification of EEG signals reveals a focal aftereffect of 10 Hz motor cortex transcranial alternating current stimulation. Cereb Cortex Commun 2022; 3:tgab067. [PMID: 35088053 PMCID: PMC8790173 DOI: 10.1093/texcom/tgab067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/21/2021] [Accepted: 12/23/2021] [Indexed: 11/15/2022] Open
Abstract
Abstract
Transcranial alternating current stimulation (tACS) modulates oscillations in a frequency- and location-specific manner and affects cognitive and motor functions. This effect appears during stimulation as well as “offline,” following stimulation, presumably reflecting neuroplasticity. Whether tACS produces long-lasting aftereffects that are physiologically meaningful, is still of current debate. Thus, for tACS to serve as a reliable method for modulating activity within neural networks, it is important to first establish whether “offline” aftereffects are robust and reliable. In this study, we employed a novel machine-learning approach to detect signatures of neuroplasticity following 10 Hz tACS to two critical nodes of the motor network: left motor cortex (lMC) and right cerebellum (rCB). To this end, we trained a classifier to distinguish between signals following lMC-tACS, rCB-tACS and sham. Our results demonstrate better classification of EEG signals in both theta (θ, 4 Hz-8 Hz) and alpha (α, 8 Hz-13 Hz) frequency bands to lMC-tACS compared to rCB-tACS/sham, at lMC-tACS stimulation location. Source reconstruction allocated these effects to premotor cortex. Stronger correlation between classification accuracies in θ and α in lMC-tACS suggested an association between θ and α efffects. Together these results suggest that EEG signals over premotor cortex contains unique signatures of neuroplasticity following 10 Hz motor cortex tACS.
Collapse
|
64
|
Cosentino G, Todisco M, Blandini F. Noninvasive neuromodulation in Parkinson's disease: Neuroplasticity implication and therapeutic perspectives. HANDBOOK OF CLINICAL NEUROLOGY 2022; 184:185-198. [PMID: 35034733 DOI: 10.1016/b978-0-12-819410-2.00010-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Noninvasive brain stimulation techniques can be used to study in vivo the changes of cortical activity and plasticity in subjects with Parkinson's disease (PD). Also, an increasing number of studies have suggested a potential therapeutic effect of these techniques. High-frequency repetitive transcranial magnetic stimulation (rTMS) and anodal transcranial direct current stimulation (tDCS) represent the most used stimulation paradigms to treat motor and nonmotor symptoms of PD. Both techniques can enhance cortical activity, compensating for its reduction related to subcortical dysfunction in PD. However, the use of suboptimal stimulation parameters can lead to therapeutic failure. Clinical studies are warranted to clarify in PD the additional effects of these stimulation techniques on pharmacologic and neurorehabilitation treatments.
Collapse
Affiliation(s)
- Giuseppe Cosentino
- Translational Neurophysiology Research Unit, IRCCS Mondino Foundation, Pavia, Italy; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
| | - Massimiliano Todisco
- Translational Neurophysiology Research Unit, IRCCS Mondino Foundation, Pavia, Italy; Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy; Movement Disorders Research Center, IRCCS Mondino Foundation, Pavia, Italy.
| | - Fabio Blandini
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy; Movement Disorders Research Center, IRCCS Mondino Foundation, Pavia, Italy
| |
Collapse
|
65
|
Mosbacher JA, Halverscheid S, Pustelnik K, Danner M, Prassl C, Brunner C, Vogel SE, Nitsche MA, Grabner RH. Theta Band Transcranial Alternating Current Stimulation Enhances Arithmetic Learning: A Systematic Comparison of Different Direct and Alternating Current Stimulations. Neuroscience 2021; 477:89-105. [PMID: 34648868 DOI: 10.1016/j.neuroscience.2021.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 10/01/2021] [Accepted: 10/04/2021] [Indexed: 11/17/2022]
Abstract
Over the last decades, interest in transcranial electrical stimulation (tES) has grown, as it might allow for causal investigations of the associations between cortical activity and cognition as well as to directly influence cognitive performance. The main objectives of the present work were to assess whether tES can enhance the acquisition and application of arithmetic abilities, and whether it enables a better assessment of underlying neurophysiological processes. To this end, the present, double-blind, sham-controlled study assessed the effects of six active stimulations (three tES protocols: anodal transcranial direct current stimulation (tDCS), alpha band transcranial alternating current stimulation (tACS), and theta band tACS; targeting the left dorsolateral prefrontal cortex or the left posterior parietal cortex) on the acquisition of an arithmetic procedure, arithmetic facts, and event-related synchronization/desynchronization (ERS/ERD) patterns. 137 healthy adults were randomly assigned to one of seven groups, each receiving one of the tES-protocols during learning. Results showed that frontal theta band tACS reduced the repetitions needed to learn novel facts and both, frontal and parietal theta band tACS accelerated the decrease in calculation times in fact learning problems. The beneficial effect of frontal theta band tACS may reflect enhanced executive functions, allowing for better control and inhibition processes and hence, a faster acquisition and integration of novel fact knowledge. However, there were no significant effects of the stimulations on procedural learning or ERS/ERD patterns. Overall, theta band tACS appears promising as a support for arithmetic fact training, but effects on procedural calculations and neurophysiological processes remain ambiguous.
Collapse
Affiliation(s)
- Jochen A Mosbacher
- Section of Educational Neuroscience, Institute of Psychology, University of Graz, Graz, Austria.
| | | | - Kolja Pustelnik
- Mathematics Institute, University of Göttingen, Göttingen, Germany
| | - Martina Danner
- Section of Educational Neuroscience, Institute of Psychology, University of Graz, Graz, Austria
| | - Christina Prassl
- Section of Educational Neuroscience, Institute of Psychology, University of Graz, Graz, Austria
| | - Clemens Brunner
- Section of Educational Neuroscience, Institute of Psychology, University of Graz, Graz, Austria
| | - Stephan E Vogel
- Section of Educational Neuroscience, Institute of Psychology, University of Graz, Graz, Austria
| | - Michael A Nitsche
- Department of Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Department of Neurology, University Medical Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Roland H Grabner
- Section of Educational Neuroscience, Institute of Psychology, University of Graz, Graz, Austria; BioTechMed Graz, Graz, Austria
| |
Collapse
|
66
|
The Role of Expectation and Beliefs on the Effects of Non-Invasive Brain Stimulation. Brain Sci 2021; 11:brainsci11111526. [PMID: 34827526 PMCID: PMC8615662 DOI: 10.3390/brainsci11111526] [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: 10/21/2021] [Revised: 11/14/2021] [Accepted: 11/16/2021] [Indexed: 11/25/2022] Open
Abstract
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.
Collapse
|
67
|
Kudo D, Koseki T, Katagiri N, Yoshida K, Takano K, Jin M, Nito M, Tanabe S, Yamaguchi T. Individualized beta-band oscillatory transcranial direct current stimulation over the primary motor cortex enhances corticomuscular coherence and corticospinal excitability in healthy individuals. Brain Stimul 2021; 15:46-52. [PMID: 34742996 DOI: 10.1016/j.brs.2021.11.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/28/2021] [Accepted: 11/01/2021] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Simultaneously modulating individual neural oscillation and cortical excitability may be important for enhancing communication between the primary motor cortex and spinal motor neurons, which plays a key role in motor control. However, it is unknown whether individualized beta-band oscillatory transcranial direct current stimulation (otDCS) enhances corticospinal oscillation and excitability. OBJECTIVE This study investigated the effects of individualized beta-band otDCS on corticomuscular coherence (CMC) and corticospinal excitability in healthy individuals. METHODS In total, 29 healthy volunteers participated in separate experiments. They received the following stimuli for 10 min on different days: 1) 2-mA otDCS with individualized beta-band frequencies, 2) 2-mA transcranial alternating current stimulation (tACS) with individualized beta-band frequencies, and 3) 2-mA transcranial direct current stimulation (tDCS). The changes in CMC between the vertex and tibialis anterior (TA) muscle and TA muscle motor-evoked potentials (MEPs) were assessed before and after (immediately, 10 min, and 20 min after) stimulation on different days. Additionally, 20-Hz otDCS for 10 min was applied to investigate the effects of a fixed beta-band frequency on CMC. RESULTS otDCS significantly increased CMC and MEPs immediately after stimulation, whereas tACS and tDCS had no effects. There was a significant negative correlation between normalized CMC changes in response to 20-Hz otDCS and the numerical difference between the 20-Hz and individualized CMC peak frequency before the stimulation. CONCLUSIONS These findings suggest that simultaneous modulation of neural oscillation and cortical excitability is critical for enhancing corticospinal communication. Individualized otDCS holds potential as a useful method in the field of neurorehabilitation.
Collapse
Affiliation(s)
- Daisuke Kudo
- Department of Physical Therapy, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagi, Yamagata-shi, Yamagata, 990-2212, Japan; Department of Physical Therapy, Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagi, Yamagata-shi, Yamagata, 990-2212, Japan.
| | - Tadaki Koseki
- Department of Physical Therapy, Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagi, Yamagata-shi, Yamagata, 990-2212, Japan.
| | - Natsuki Katagiri
- Department of Physical Therapy, Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagi, Yamagata-shi, Yamagata, 990-2212, Japan.
| | - Kaito Yoshida
- Department of Physical Therapy, Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagi, Yamagata-shi, Yamagata, 990-2212, Japan.
| | - Keita Takano
- Department of Physical Therapy, Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagi, Yamagata-shi, Yamagata, 990-2212, Japan.
| | - Masafumi Jin
- Department of Physical Therapy, Graduate School of Health Sciences, Yamagata Prefectural University of Health Sciences, 260 Kamiyanagi, Yamagata-shi, Yamagata, 990-2212, Japan.
| | - Mitsuhiro Nito
- Department of Anatomy and Structural Science, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata, 990-9585, Japan.
| | - Shigeo Tanabe
- Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake-shi, Aichi, 470-1192, Japan.
| | - Tomofumi Yamaguchi
- Department of Physical Therapy, Faculty of Health Science, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
| |
Collapse
|
68
|
Wang H, Sun W, Zhang J, Yan Z, Wang C, Wang L, Liu T, Li C, Chen D, Shintaro F, Wu J, Yan T. Influence of layered skull modeling on the frequency sensitivity and target accuracy in simulations of transcranial current stimulation. Hum Brain Mapp 2021; 42:5345-5356. [PMID: 34390079 PMCID: PMC8519867 DOI: 10.1002/hbm.25622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 06/29/2021] [Accepted: 07/31/2021] [Indexed: 11/27/2022] Open
Abstract
With the development of electrical stimulation technology, especially the emergence of temporally interfering (TI) stimulation, it is necessary to discuss the influence of current frequency on stimulation intensity. Accurate skull modeling is important for transcranial current stimulation (tCS) simulation prediction because of its large role in dispersing current. In this study, we simulated different frequencies of transcranial alternating current stimulation (tACS) and TI stimulation in single-layer and layered skull model, compared the electric field via error parameters such as the relative difference measure and relative magnification factor. Pearson correlation analysis and t-test were used to measure the differences in envelope amplitude. The results showed that the intensity of electric field in the brain generated by per unit of stimulation current will increase with current frequency, and the layered skull model had a better response to frequency. An obvious pattern difference was found between the electric fields of the layered and single-layer skull individualized models. For TI stimulation, the Pearson correlation coefficient between the envelope distribution of the layered skull model and the single-layer skull was only 0.746 in the individualized model, which is clearly lower than the correlation coefficient of 0.999 determined from the spherical model. Higher carrier frequencies seemed to be easier to generate a large enough brain electric field envelope in TI stimulation. In conclusion, we recommend using layered skull models instead of single-layer skull models in tCS (particularly TI stimulation) simulation studies in order to improve the accuracy of the prediction of stimulus intensity and stimulus target.
Collapse
Affiliation(s)
- Heng Wang
- School of Mechatronical EngineeringBeijing Institute of TechnologyBeijingChina
| | - Weiqian Sun
- School of Life ScienceBeijing Institute of TechnologyBeijingChina
| | - Jianxu Zhang
- School of Mechatronical EngineeringBeijing Institute of TechnologyBeijingChina
| | - Zilong Yan
- School of Mechatronical EngineeringBeijing Institute of TechnologyBeijingChina
| | - Chenyu Wang
- School of Mechatronical EngineeringBeijing Institute of TechnologyBeijingChina
| | - Luyao Wang
- School of Mechatronical EngineeringBeijing Institute of TechnologyBeijingChina
| | - Tiantian Liu
- School of Life ScienceBeijing Institute of TechnologyBeijingChina
| | - Chunlin Li
- School of Biomedical EngineeringCapital Medical UniversityBeijingChina
| | - Duanduan Chen
- School of Life ScienceBeijing Institute of TechnologyBeijingChina
| | | | - Jinglong Wu
- School of Mechatronical EngineeringBeijing Institute of TechnologyBeijingChina
- Department of Neurology and NeuroscienceOkayama UniversityOkayamaJapan
| | - Tianyi Yan
- School of Life ScienceBeijing Institute of TechnologyBeijingChina
| |
Collapse
|
69
|
Coldea A, Morand S, Veniero D, Harvey M, Thut G. Parietal alpha tACS shows inconsistent effects on visuospatial attention. PLoS One 2021; 16:e0255424. [PMID: 34351972 PMCID: PMC8341497 DOI: 10.1371/journal.pone.0255424] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/15/2021] [Indexed: 11/19/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) is a popular technique that has been used for manipulating brain oscillations and inferring causality regarding the brain-behaviour relationship. Although it is a promising tool, the variability of tACS results has raised questions regarding the robustness and reproducibility of its effects. Building on recent research using tACS to modulate visuospatial attention, we here attempted to replicate findings of lateralized parietal tACS at alpha frequency to induce a change in attention bias away from the contra- towards the ipsilateral visual hemifield. 40 healthy participants underwent tACS in two separate sessions where either 10 Hz tACS or sham was applied via a high-density montage over the left parietal cortex at 1.5 mA for 20 min, while performance was assessed in an endogenous attention task. Task and tACS parameters were chosen to match those of previous studies reporting positive effects. Unlike these studies, we did not observe lateralized parietal alpha tACS to affect attention deployment or visual processing across the hemifields as compared to sham. Likewise, additional resting electroencephalography immediately offline to tACS did not reveal any notable effects on individual alpha power or frequency. Our study emphasizes the need for more replication studies and systematic investigations of the factors that drive tACS effects.
Collapse
Affiliation(s)
- Andra Coldea
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
| | - Stephanie Morand
- School of Life Sciences, MVLS College, University of Glasgow, Glasgow, United Kingdom
| | - Domenica Veniero
- School of Psychology, University of Nottingham, Nottingham, United Kingdom
| | - Monika Harvey
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
| | - Gregor Thut
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
| |
Collapse
|
70
|
Acevedo N, Bosanac P, Pikoos T, Rossell S, Castle D. Therapeutic Neurostimulation in Obsessive-Compulsive and Related Disorders: A Systematic Review. Brain Sci 2021; 11:brainsci11070948. [PMID: 34356182 PMCID: PMC8307974 DOI: 10.3390/brainsci11070948] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/09/2021] [Accepted: 07/10/2021] [Indexed: 01/16/2023] Open
Abstract
Invasive and noninvasive neurostimulation therapies for obsessive-compulsive and related disorders (OCRD) were systematically reviewed with the aim of assessing clinical characteristics, methodologies, neuroanatomical substrates, and varied stimulation parameters. Previous reviews have focused on a narrow scope, statistical rather than clinical significance, grouped together heterogenous protocols, and proposed inconclusive outcomes and directions. Herein, a comprehensive and transdiagnostic evaluation of all clinically relevant determinants is presented with translational clinical recommendations and novel response rates. Electroconvulsive therapy (ECT) studies were limited in number and quality but demonstrated greater efficacy than previously identified. Targeting the pre-SMA/SMA is recommended for transcranial direct current stimulation (tDCS) and transcranial magnetic stimulation (TMS). TMS yielded superior outcomes, although polarity findings were conflicting, and refinement of frontal/cognitive control protocols may optimize outcomes. For both techniques, standardization of polarity, more treatment sessions (>20), and targeting multiple structures are encouraged. A deep brain stimulation (DBS) 'sweet spot' of the striatum for OCD was proposed, and CBT is strongly encouraged. Tourette's patients showed less variance and reliance on treatment optimization. Several DBS targets achieved consistent, rapid, and sustained clinical response. Analysis of fiber connectivity, as opposed to precise neural regions, should be implemented for target selection. Standardization of protocols is necessary to achieve translational outcomes.
Collapse
Affiliation(s)
- Nicola Acevedo
- Centre for Mental Health, Swinburne University of Technology, John Street, Melbourne, VIC 3122, Australia; (T.P.); (S.R.)
- Correspondence:
| | - Peter Bosanac
- St. Vincent’s Hospital Melbourne, 41 Victoria Parade, Melbourne, VIC 3065, Australia; (P.B.); (D.C.)
- Department of Psychiatry, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Toni Pikoos
- Centre for Mental Health, Swinburne University of Technology, John Street, Melbourne, VIC 3122, Australia; (T.P.); (S.R.)
| | - Susan Rossell
- Centre for Mental Health, Swinburne University of Technology, John Street, Melbourne, VIC 3122, Australia; (T.P.); (S.R.)
- St. Vincent’s Hospital Melbourne, 41 Victoria Parade, Melbourne, VIC 3065, Australia; (P.B.); (D.C.)
| | - David Castle
- St. Vincent’s Hospital Melbourne, 41 Victoria Parade, Melbourne, VIC 3065, Australia; (P.B.); (D.C.)
- Department of Psychiatry, University of Melbourne, Melbourne, VIC 3010, Australia
- Centre for Addiction and Mental Health, 252 College Street, Toronto, ON M5T 1R7, Canada
| |
Collapse
|
71
|
Orendáčová M, Kvašňák E. Effects of Transcranial Alternating Current Stimulation and Neurofeedback on Alpha (EEG) Dynamics: A Review. Front Hum Neurosci 2021; 15:628229. [PMID: 34305549 PMCID: PMC8297546 DOI: 10.3389/fnhum.2021.628229] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 06/03/2021] [Indexed: 12/14/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) and neurofeedback (NFB) are two different types of non-invasive neuromodulation techniques, which can modulate brain activity and improve brain functioning. In this review, we compared the current state of knowledge related to the mechanisms of tACS and NFB and their effects on electroencephalogram (EEG) activity (online period/stimulation period) and on aftereffects (offline period/post/stimulation period), including the duration of their persistence and potential behavioral benefits. Since alpha bandwidth has been broadly studied in NFB and in tACS research, the studies of NFB and tACS in modulating alpha bandwidth were selected for comparing the online and offline effects of these two neuromodulation techniques. The factors responsible for variability in the responsiveness of the modulated EEG activity by tACS and NFB were analyzed and compared too. Based on the current literature related to tACS and NFB, it can be concluded that tACS and NFB differ a lot in the mechanisms responsible for their effects on an online EEG activity but they possibly share the common universal mechanisms responsible for the induction of aftereffects in the targeted stimulated EEG band, namely Hebbian and homeostatic plasticity. Many studies of both neuromodulation techniques report the aftereffects connected to the behavioral benefits. The duration of persistence of aftereffects for NFB and tACS is comparable. In relation to the factors influencing responsiveness to tACS and NFB, significantly more types of factors were analyzed in the NFB studies compared to the tACS studies. Several common factors for both tACS and NFB have been already investigated. Based on these outcomes, we propose several new research directions regarding tACS and NFB.
Collapse
Affiliation(s)
- Mária Orendáčová
- Department of Medical Biophysics and Medical Informatics, Third Faculty of Medicine, Charles University in Prague, Prague, Czechia
| | | |
Collapse
|
72
|
Thompson L, Khuc J, Saccani MS, Zokaei N, Cappelletti M. Gamma oscillations modulate working memory recall precision. Exp Brain Res 2021; 239:2711-2724. [PMID: 34223958 PMCID: PMC8448714 DOI: 10.1007/s00221-021-06051-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 01/25/2021] [Indexed: 12/13/2022]
Abstract
Working memory (WM)—the ability to keep information in mind for short periods of time—is linked to attention and inhibitory abilities, i.e., the capacity to ignore task-irrelevant information. These abilities have been associated with brain oscillations, especially parietal gamma and alpha bands, but it is yet unknown whether these oscillations also modulate attention and inhibitory abilities. To test this, we compared parietal gamma-transcranial alternating current stimulation (tACS) to alpha-tACS and to a non-stimulation condition (Sham) in 51 young participants. Stimulation was coupled with a WM task probing memory-based attention and inhibitory abilities by means of probabilistic retrospective cues, including informative (valid), uninformative (invalid) and neutral. Our results show that relative to alpha and sham stimulation, parietal gamma-tACS significantly increased working memory recall precision. Additional post hoc analyses also revealed strong individual variability before and following stimulation; low-baseline performers showed no significant changes in performance following both gamma and alpha-tACS relative to sham. In contrast, in high-baseline performers gamma- (but not alpha) tACS selectively and significantly improved misbinding-feature errors as well as memory precision, particularly in uninformative (invalid) cues which rely more strongly on attentional abilities. We concluded that parietal gamma oscillations, therefore, modulate working memory recall processes, although baseline performance may further influence the effect of stimulation.
Collapse
Affiliation(s)
- Lyall Thompson
- Department of Psychology, Goldsmiths, University of London, Lewisham Way, London, SE14 6NW, UK
| | - Janine Khuc
- Department of Psychology, Goldsmiths, University of London, Lewisham Way, London, SE14 6NW, UK
| | - Maria Silvia Saccani
- Department of Psychology, Goldsmiths, University of London, Lewisham Way, London, SE14 6NW, UK
| | - Nahid Zokaei
- Department of Experimental Psychology, South Parks Road, Oxford, OX1 3UD, UK.,Department of Psychiatry, Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, OX3 7JX, UK
| | - Marinella Cappelletti
- Department of Psychology, Goldsmiths, University of London, Lewisham Way, London, SE14 6NW, UK. .,Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, WC1N 3AR, UK.
| |
Collapse
|
73
|
Erkens J, Schulte M, Vormann M, Wilsch A, Herrmann CS. Hearing Impaired Participants Improve More Under Envelope-Transcranial Alternating Current Stimulation When Signal to Noise Ratio Is High. Neurosci Insights 2021; 16:2633105520988854. [PMID: 33709079 PMCID: PMC7907945 DOI: 10.1177/2633105520988854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 12/31/2020] [Indexed: 11/16/2022] Open
Abstract
An issue commonly expressed by hearing aid users is a difficulty to understand speech in complex hearing scenarios, that is, when speech is presented together with background noise or in situations with multiple speakers. Conventional hearing aids are already designed with these issues in mind, using beamforming to only enhance sound from a specific direction, but these are limited in solving these issues as they can only modulate incoming sound at the cochlear level. However, evidence exists that age-related hearing loss might partially be caused later in the hearing processes due to brain processes slowing down and becoming less efficient. In this study, we tested whether it would be possible to improve the hearing process at the cortical level by improving neural tracking of speech. The speech envelopes of target sentences were transformed into an electrical signal and stimulated onto elderly participants' cortices using transcranial alternating current stimulation (tACS). We compared 2 different signal to noise ratios (SNRs) with 5 different delays between sound presentation and stimulation ranging from 50 ms to 150 ms, and the differences in effects between elderly normal hearing and elderly hearing impaired participants. When the task was performed at a high SNR, hearing impaired participants appeared to gain more from envelope-tACS compared to when the task was performed at a lower SNR. This was not the case for normal hearing participants. Furthermore, a post-hoc analysis of the different time-lags suggest that elderly were significantly better at a stimulation time-lag of 150 ms when the task was presented at a high SNR. In this paper, we outline why these effects are worth exploring further, and what they tell us about the optimal tACS time-lag.
Collapse
Affiliation(s)
- Jules Erkens
- Department of Psychology, Cluster of
Excellence “Hearing4All,” European Medical School, Carl von Ossietzky University,
Oldenburg, Germany
| | | | | | - Anna Wilsch
- Department of Psychology, Cluster of
Excellence “Hearing4All,” European Medical School, Carl von Ossietzky University,
Oldenburg, Germany
| | - Christoph S Herrmann
- Department of Psychology, Cluster of
Excellence “Hearing4All,” European Medical School, Carl von Ossietzky University,
Oldenburg, Germany
- Research Center Neurosensory Science,
Carl von Ossietzky University, Oldenburg, Germany
| |
Collapse
|
74
|
Korai SA, Ranieri F, Di Lazzaro V, Papa M, Cirillo G. Neurobiological After-Effects of Low Intensity Transcranial Electric Stimulation of the Human Nervous System: From Basic Mechanisms to Metaplasticity. Front Neurol 2021; 12:587771. [PMID: 33658972 PMCID: PMC7917202 DOI: 10.3389/fneur.2021.587771] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 01/04/2021] [Indexed: 12/19/2022] Open
Abstract
Non-invasive low-intensity transcranial electrical stimulation (tES) of the brain is an evolving field that has brought remarkable attention in the past few decades for its ability to directly modulate specific brain functions. Neurobiological after-effects of tES seems to be related to changes in neuronal and synaptic excitability and plasticity, however mechanisms are still far from being elucidated. We aim to review recent results from in vitro and in vivo studies that highlight molecular and cellular mechanisms of transcranial direct (tDCS) and alternating (tACS) current stimulation. Changes in membrane potential and neural synchronization explain the ongoing and short-lasting effects of tES, while changes induced in existing proteins and new protein synthesis is required for long-lasting plastic changes (LTP/LTD). Glial cells, for decades supporting elements, are now considered constitutive part of the synapse and might contribute to the mechanisms of synaptic plasticity. This review brings into focus the neurobiological mechanisms and after-effects of tDCS and tACS from in vitro and in vivo studies, in both animals and humans, highlighting possible pathways for the development of targeted therapeutic applications.
Collapse
Affiliation(s)
- Sohaib Ali Korai
- Division of Human Anatomy - Laboratory of Neuronal Networks, University of Campania "Luigi Vanvitelli", Naples, Italy
| | - Federico Ranieri
- Neurology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Vincenzo Di Lazzaro
- Neurology, Neurophysiology and Neurobiology Unit, University Campus Bio-Medico, Rome, Italy
| | - Michele Papa
- Division of Human Anatomy - Laboratory of Neuronal Networks, University of Campania "Luigi Vanvitelli", Naples, Italy.,ISBE Italy, SYSBIO Centre of Systems Biology, Milan, Italy
| | - Giovanni Cirillo
- Division of Human Anatomy - Laboratory of Neuronal Networks, University of Campania "Luigi Vanvitelli", Naples, Italy.,Neurology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| |
Collapse
|
75
|
Vallence AM, Dansie K, Goldsworthy MR, McAllister SM, Yang R, Rothwell JC, Ridding MC. Examining motor evoked potential amplitude and short-interval intracortical inhibition on the up-going and down-going phases of a transcranial alternating current stimulation (tacs) imposed alpha oscillation. Eur J Neurosci 2021; 53:2755-2762. [PMID: 33480046 DOI: 10.1111/ejn.15124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 12/19/2020] [Accepted: 01/17/2021] [Indexed: 01/18/2023]
Abstract
Many brain regions exhibit rhythmical activity thought to reflect the summed behaviour of large populations of neurons. The endogenous alpha rhythm has been associated with phase-dependent modulation of corticospinal excitability. However, whether exogenous alpha rhythm, induced using transcranial alternating current stimulation (tACS) also has a phase-dependent effect on corticospinal excitability remains unknown. Here, we triggered transcranial magnetic stimuli (TMS) on the up- or down-going phase of a tACS-imposed alpha oscillation and measured motor evoked potential (MEP) amplitude and short-interval intracortical inhibition (SICI). There was no significant difference in MEP amplitude or SICI when TMS was triggered on the up- or down-going phase of the tACS-imposed alpha oscillation. The current study provides no evidence of differences in corticospinal excitability or GABAergic inhibition when targeting the up-going (peak) and down-going (trough) phase of the tACS-imposed oscillation.
Collapse
Affiliation(s)
- Ann-Maree Vallence
- Discipline of Psychology, College of Science, Health, Engineering, and Education, Murdoch University, Perth, Australia
| | - Kathryn Dansie
- Australia and New Zealand Dialysis and Transplant Registry (ANZDATA), South Australian Health and Medical Research Institute (SAHMIR), Adelaide, South, Australia
| | - Mitchell R Goldsworthy
- Adelaide Medical School, University of Adelaide, Adelaide, Australia.,Hopwood Centre for Neurobiology, Lifelong Health Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, Australia
| | - Suzanne M McAllister
- Formerly of the Discipline of Physiology, School of Medical Science, University of Adelaide, Adelaide, Australia
| | | | - John C Rothwell
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - Michael C Ridding
- University of South Australia, IIMPACT in Health, Adelaide, Australia
| |
Collapse
|
76
|
De Koninck BP, Guay S, Blais H, De Beaumont L. Parametric study of transcranial alternating current stimulation for brain alpha power modulation. Brain Commun 2021; 3:fcab010. [PMID: 34085039 PMCID: PMC8165484 DOI: 10.1093/braincomms/fcab010] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 11/04/2020] [Accepted: 12/10/2020] [Indexed: 12/02/2022] Open
Abstract
Transcranial alternating current stimulation, a non-invasive brain stimulation technique, has been used to increase alpha (8-12 Hz) power, the latter being associated with various brain functions and states. Heterogeneity among stimulation parameters across studies makes it difficult to implement reliable transcranial alternating current stimulation protocols, explaining the absence of consensus on optimal stimulation parameters to modulate the alpha rhythm. This project documents the differential impact of controlling for key transcranial alternating current stimulation parameters, namely the intensity, the frequency and the stimulation site (anterior versus posterior). Phase 1:20 healthy participants underwent 4 different stimulation conditions. In each experimental condition, stimulation via 2 electrodes was delivered for 20 min. Stimulation conditions were administered at PO7-PO8 or F3-F4 at individual's alpha frequency, or at individual's theta frequency or sham. Stimulation intensity was set according to each participant's comfort following a standardized unpleasantness scale (≤ 40 out of 100) and could not exceed 6 mA. All conditions were counterbalanced. Phase 2: participants who tolerated higher intensity of stimulation (4-6 mA) underwent alpha-frequency stimulation applied over PO7-PO8 at 1 mA to investigate within-subject modulation of stimulation response according to stimulation intensity. Whether set over posterior or anterior cortical sites, alpha-frequency stimulation showed greater increase in alpha power relative to stimulation at theta frequency and sham stimulation. Posterior alpha-frequency stimulation showed a greater increase in alpha power relative to the adjacent frequency bands over frontal and occipito-parietal brain areas. Low intensity (1 mA) posterior alpha stimulation showed a similar increase in alpha power than at high (4-6 mA) intensity when measured immediately after stimulation. However, when tested at 60 min or 120 min, low intensity stimulation was associated with significantly superior alpha power increase relative to high intensity stimulation. This study shows that posterior individual's alpha frequency stimulation at higher intensities is well tolerated but fails to increase stimulation aftereffects recorded within 2 h of stimulation on brain oscillations of the corresponding frequency band. In sharp contrast, stimulating at 1 mA (regardless of phosphene generation or sensory perception) effectively and selectively modulates alpha power within that 2-h time window, thus validating that it as a reliable stimulus intensity for future studies. This study also shows that posterior alpha-frequency stimulation preferentially modulates endogenous brain oscillations of the corresponding frequency band. Moreover, our data suggest that posterior alpha-frequency transcranial alternating current stimulation is a reliable and precise non-invasive brain stimulation technique for persistent modulation of both frontal and occipito-parietal alpha power.
Collapse
Affiliation(s)
- Beatrice P De Koninck
- Research Center, Hôpital du Sacré-Coeur de Montréal, CIUSSS du Nord-de-l’Île-de-Montréal Research Center (CRHSCM), H4J 1C5, Montreal, Québec, Canada
- Department of Surgery, Université De Montréal, H3T1J4, Montreal, Québec, Canada
| | - Samuel Guay
- Research Center, Hôpital du Sacré-Coeur de Montréal, CIUSSS du Nord-de-l’Île-de-Montréal Research Center (CRHSCM), H4J 1C5, Montreal, Québec, Canada
- Department of Surgery, Université De Montréal, H3T1J4, Montreal, Québec, Canada
| | - Hélène Blais
- Research Center, Hôpital du Sacré-Coeur de Montréal, CIUSSS du Nord-de-l’Île-de-Montréal Research Center (CRHSCM), H4J 1C5, Montreal, Québec, Canada
| | - Louis De Beaumont
- Research Center, Hôpital du Sacré-Coeur de Montréal, CIUSSS du Nord-de-l’Île-de-Montréal Research Center (CRHSCM), H4J 1C5, Montreal, Québec, Canada
- Department of Surgery, Université De Montréal, H3T1J4, Montreal, Québec, Canada
| |
Collapse
|
77
|
van Boekholdt L, Kerstens S, Khatoun A, Asamoah B, Mc Laughlin M. tDCS peripheral nerve stimulation: a neglected mode of action? Mol Psychiatry 2021; 26:456-461. [PMID: 33299136 DOI: 10.1038/s41380-020-00962-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/19/2020] [Accepted: 11/16/2020] [Indexed: 11/09/2022]
Abstract
Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation method widely used by neuroscientists and clinicians for research and therapeutic purposes. tDCS is currently under investigation as a treatment for a range of psychiatric disorders. Despite its popularity, a full understanding of tDCS's underlying neurophysiological mechanisms is still lacking. tDCS creates a weak electric field in the cerebral cortex which is generally assumed to cause the observed effects. Interestingly, as tDCS is applied directly on the skin, localized peripheral nerve endings are exposed to much higher electric field strengths than the underlying cortices. Yet, the potential contribution of peripheral mechanisms in causing tDCS's effects has never been systemically investigated. We hypothesize that tDCS induces arousal and vigilance through peripheral mechanisms. We suggest that this may involve peripherally-evoked activation of the ascending reticular activating system, in which norepinephrine is distributed throughout the brain by the locus coeruleus. Finally, we provide suggestions to improve tDCS experimental design beyond the standard sham control, such as topical anesthetics to block peripheral nerves and active controls to stimulate non-target areas. Broad adoption of these measures in all tDCS experiments could help disambiguate peripheral from true transcranial tDCS mechanisms.
Collapse
Affiliation(s)
- Luuk van Boekholdt
- Exp ORL, Department of Neuroscience, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Silke Kerstens
- Exp ORL, Department of Neuroscience, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Ahmad Khatoun
- Exp ORL, Department of Neuroscience, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Boateng Asamoah
- Exp ORL, Department of Neuroscience, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Myles Mc Laughlin
- Exp ORL, Department of Neuroscience, Leuven Brain Institute, KU Leuven, Leuven, Belgium.
| |
Collapse
|
78
|
Elyamany O, Leicht G, Herrmann CS, Mulert C. Transcranial alternating current stimulation (tACS): from basic mechanisms towards first applications in psychiatry. Eur Arch Psychiatry Clin Neurosci 2021; 271:135-156. [PMID: 33211157 PMCID: PMC7867505 DOI: 10.1007/s00406-020-01209-9] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 10/27/2020] [Indexed: 12/11/2022]
Abstract
Transcranial alternating current stimulation (tACS) is a unique form of non-invasive brain stimulation. Sinusoidal alternating electric currents are delivered to the scalp to affect mostly cortical neurons. tACS is supposed to modulate brain function and, in turn, cognitive processes by entraining brain oscillations and inducing long-term synaptic plasticity. Therefore, tACS has been investigated in cognitive neuroscience, but only recently, it has been also introduced in psychiatric clinical trials. This review describes current concepts and first findings of applying tACS as a potential therapeutic tool in the field of psychiatry. The current understanding of its mechanisms of action is explained, bridging cellular neuronal activity and the brain network mechanism. Revisiting the relevance of altered brain oscillations found in six major psychiatric disorders, putative targets for the management of mental disorders using tACS are discussed. A systematic literature search on PubMed was conducted to report findings of the clinical studies applying tACS in patients with psychiatric conditions. In conclusion, the initial results may support the feasibility of tACS in clinical psychiatric populations without serious adverse events. Moreover, these results showed the ability of tACS to reset disturbed brain oscillations, and thus to improve behavioural outcomes. In addition to its potential therapeutic role, the reactivity of the brain circuits to tACS could serve as a possible tool to determine the diagnosis, classification or prognosis of psychiatric disorders. Future double-blind randomised controlled trials are necessary to answer currently unresolved questions. They may aim to detect response predictors and control for various confounding factors.
Collapse
Affiliation(s)
- Osama Elyamany
- Centre of Psychiatry, Justus-Liebig University, Klinikstrasse 36, 35392, Giessen, Hessen, Germany
- Centre for Mind, Brain and Behaviour (CMBB), University of Marburg and Justus-Liebig University Giessen, Marburg, Germany
| | - Gregor Leicht
- Department of Psychiatry and Psychotherapy, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany
| | - Christoph S Herrmann
- Experimental Psychology Lab, Centre for Excellence "Hearing4all," European Medical School, University of Oldenburg, Oldenburg, Lower Saxony, Germany
- Research Centre Neurosensory Science, University of Oldenburg, Oldenburg, Lower Saxony, Germany
| | - Christoph Mulert
- Centre of Psychiatry, Justus-Liebig University, Klinikstrasse 36, 35392, Giessen, Hessen, Germany.
- Centre for Mind, Brain and Behaviour (CMBB), University of Marburg and Justus-Liebig University Giessen, Marburg, Germany.
| |
Collapse
|
79
|
Delnoy B, Coelho AI, Rubio-Gozalbo ME. Current and Future Treatments for Classic Galactosemia. J Pers Med 2021; 11:jpm11020075. [PMID: 33525536 PMCID: PMC7911353 DOI: 10.3390/jpm11020075] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/23/2021] [Accepted: 01/24/2021] [Indexed: 02/07/2023] Open
Abstract
Type I (classic) galactosemia, galactose 1-phosphate uridylyltransferase (GALT)-deficiency is a hereditary disorder of galactose metabolism. The current therapeutic standard of care, a galactose-restricted diet, is effective in treating neonatal complications but is inadequate in preventing burdensome complications. The development of several animal models of classic galactosemia that (partly) mimic the biochemical and clinical phenotypes and the resolution of the crystal structure of GALT have provided important insights; however, precise pathophysiology remains to be elucidated. Novel therapeutic approaches currently being explored focus on several of the pathogenic factors that have been described, aiming to (i) restore GALT activity, (ii) influence the cascade of events and (iii) address the clinical picture. This review attempts to provide an overview on the latest advancements in therapy approaches.
Collapse
Affiliation(s)
- Britt Delnoy
- Department of Pediatrics, Maastricht University Medical Centre, 6229 HX Maastricht, The Netherlands; (B.D.); (A.I.C.)
- Department of Clinical Genetics, Maastricht University Medical Centre+, 6229 HX Maastricht, The Netherlands
- GROW-School for Oncology and Developmental Biology, Maastricht University, 6229 HX Maastricht, The Netherlands
| | - Ana I. Coelho
- Department of Pediatrics, Maastricht University Medical Centre, 6229 HX Maastricht, The Netherlands; (B.D.); (A.I.C.)
| | - Maria Estela Rubio-Gozalbo
- Department of Pediatrics, Maastricht University Medical Centre, 6229 HX Maastricht, The Netherlands; (B.D.); (A.I.C.)
- Department of Clinical Genetics, Maastricht University Medical Centre+, 6229 HX Maastricht, The Netherlands
- GROW-School for Oncology and Developmental Biology, Maastricht University, 6229 HX Maastricht, The Netherlands
- Correspondence: ; Tel.: +31-43-3872920
| |
Collapse
|
80
|
Haller N, Hasan A, Padberg F, Strube W, da Costa Lane Valiengo L, Brunoni AR, Brunelin J, Palm U. [Transcranial electrical brain stimulation methods for treatment of negative symptoms in schizophrenia]. DER NERVENARZT 2021; 93:41-50. [PMID: 33492411 PMCID: PMC8763819 DOI: 10.1007/s00115-021-01065-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 01/08/2021] [Indexed: 11/24/2022]
Abstract
Über die letzten Jahre entwickelten sich Neuromodulationsverfahren zu einer dritten Säule neben Pharmakotherapie und Psychotherapie in der Behandlung psychischer Erkrankungen. Besonders in der Behandlung von Menschen mit einer Schizophrenie könnten Hirnstimulationsverfahren eine Alternative oder Ergänzung zu den etablierten Therapiestrategien darstellen. Die meist vorhandenen Positivsymptome können zumeist mit Antipsychotika adäquat behandelt werden. Gerade bei Patienten mit Schizophrenie besitzen jedoch Negativsymptome einen überdauernden Krankheitswert und beeinflussen den Verlauf durch globale Antriebsverarmung und beeinträchtigte Kognition im alltäglichen Leben negativ. Dieser Übersichtsartikel stellt eine Zusammenfassung über die verschiedenen nichtinvasiven Hirnstimulationsverfahren transkranielle Gleichstromstimulation (transcranial direct current stimulation, tDCS), Wechselstromstimulation (transcranial alternating current stimulation, tACS) sowie Rauschstromstimulation (transcranial random noise stimulation, tRNS) zur Behandlung der Negativsymptomatik bei Schizophrenie dar. Die neuen transkraniellen Hirnstimulationsverfahren könnten dabei helfen, gestörte neuronale Vernetzungen wieder herzustellen und die Konnektivität vor allem der dorsolateralen präfrontalen Anteile des Kortex zu verbessern. Einige Studien weisen auf eine Verbesserung der Negativsymptome durch Behandlung mit tDCS, tACS bzw. tRNS hin und könnten so neue Therapiemöglichkeiten in der Behandlung der Schizophrenie darstellen.
Collapse
Affiliation(s)
- Nikolas Haller
- Klinik für Psychiatrie und Psychotherapie, Klinikum der Universität München, München, Deutschland
| | - Alkomiet Hasan
- Klinik für Psychiatrie und Psychotherapie, Klinikum der Universität München, München, Deutschland.,Klinik für Psychiatrie, Psychotherapie und Psychosomatik, Universität Augsburg, Medizinische Fakultät, BKH Augsburg, Augsburg, Deutschland
| | - Frank Padberg
- Klinik für Psychiatrie und Psychotherapie, Klinikum der Universität München, München, Deutschland
| | - Wolfgang Strube
- Klinik für Psychiatrie, Psychotherapie und Psychosomatik, Universität Augsburg, Medizinische Fakultät, BKH Augsburg, Augsburg, Deutschland
| | - Leandro da Costa Lane Valiengo
- Laboratory of Neurosciences (LIM-27), Department and Institute of Psychiatry, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brasilien
| | - Andre R Brunoni
- Laboratory of Neurosciences (LIM-27), Department and Institute of Psychiatry, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brasilien
| | - Jerome Brunelin
- CH le Vinatier, INSERM U 1028, CNRS UMR 5292, PSYR2 Team, Centre de recherche en neuroscience de Lyon, Université de Lyon, Lyon, Frankreich
| | - Ulrich Palm
- Klinik für Psychiatrie und Psychotherapie, Klinikum der Universität München, München, Deutschland. .,Medical Park Chiemseeblick, Rasthausstr. 25, 83233, Bernau-Felden, Deutschland.
| |
Collapse
|
81
|
Beppi C, Ribeiro Violante I, Scott G, Sandrone S. EEG, MEG and neuromodulatory approaches to explore cognition: Current status and future directions. Brain Cogn 2021; 148:105677. [PMID: 33486194 DOI: 10.1016/j.bandc.2020.105677] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 12/26/2020] [Accepted: 12/27/2020] [Indexed: 01/04/2023]
Abstract
Neural oscillations and their association with brain states and cognitive functions have been object of extensive investigation over the last decades. Several electroencephalography (EEG) and magnetoencephalography (MEG) analysis approaches have been explored and oscillatory properties have been identified, in parallel with the technical and computational advancement. This review provides an up-to-date account of how EEG/MEG oscillations have contributed to the understanding of cognition. Methodological challenges, recent developments and translational potential, along with future research avenues, are discussed.
Collapse
Affiliation(s)
- Carolina Beppi
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland; Department of Neurology, University Hospital Zurich and University of Zurich, Zurich, Switzerland; Clinical Neuroscience Center, University Hospital Zurich and University of Zurich, Zurich, Switzerland.
| | - Inês Ribeiro Violante
- Computational, Cognitive and Clinical Neuroscience Laboratory (C3NL), Department of Brain Sciences, Imperial College London, London, United Kingdom; School of Psychology, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.
| | - Gregory Scott
- Computational, Cognitive and Clinical Neuroscience Laboratory (C3NL), Department of Brain Sciences, Imperial College London, London, United Kingdom.
| | - Stefano Sandrone
- Computational, Cognitive and Clinical Neuroscience Laboratory (C3NL), Department of Brain Sciences, Imperial College London, London, United Kingdom.
| |
Collapse
|
82
|
Lajoie K, Marigold DS, Valdés BA, Menon C. The potential of noisy galvanic vestibular stimulation for optimizing and assisting human performance. Neuropsychologia 2021; 152:107751. [PMID: 33434573 DOI: 10.1016/j.neuropsychologia.2021.107751] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 01/07/2021] [Accepted: 01/08/2021] [Indexed: 12/17/2022]
Abstract
Noisy galvanic vestibular stimulation (nGVS) is an emerging non-invasive brain stimulation technique. It involves applying alternating currents of different frequencies and amplitudes presented in a random, or noisy, manner through electrodes on the mastoid bones behind the ears. Because it directly activates vestibular hair cells and afferents and has an indirect effect on a variety of brain regions, it has the potential to impact many different functions. The objective of this review is twofold: (1) to review how nGVS affects motor, sensory, and cognitive performance in healthy adults; and (2) to discuss potential clinical applications of nGVS. First, we introduce the technique. We then describe the regions receiving and processing vestibular information. Next, we discuss the effects of nGVS on motor, sensory, and cognitive function in healthy adults. Subsequently, we outline its potential clinical applications. Finally, we highlight other electrical stimulation technologies and discuss why nGVS offers an alternative or complementary approach. Overall, nGVS appears promising for optimizing human performance and as an assistive technology, though further research is required.
Collapse
Affiliation(s)
- Kim Lajoie
- Menrva Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada
| | - Daniel S Marigold
- Sensorimotor Neuroscience Lab, Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
| | - Bulmaro A Valdés
- Menrva Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada
| | - Carlo Menon
- Menrva Research Group, Schools of Mechatronic Systems Engineering and Engineering Science, Simon Fraser University, Metro Vancouver, BC, Canada.
| |
Collapse
|
83
|
Trofimov AO, Kopylov AA, Martynov DS, Zorkova AV, Trofimova K, Cheremuhin PN, Bragin DE. The Changes in Brain Oxygenation During Transcranial Alternating Current Stimulation as Consequences of Traumatic Brain Injury: A Near-Infrared Spectroscopy Study. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1269:235-239. [PMID: 33966223 PMCID: PMC9126087 DOI: 10.1007/978-3-030-48238-1_37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The aim was to evaluate the changes in brain tissue oxygenation, assessed by near-infrared spectroscopy (NIRS), during transcranial alternating current stimulation (tACS) in patients with mild and moderate traumatic brain injury (TBI). Nineteen patients with diffuse, blunt, non-severe TBI (mean age 32.7 ± 11.4 years; 4 women and 15 men; Glasgow Coma Score before tACS 14.1 ± 0.5) were treated by 10 Hz in-phase tACS applied for 30 minutes to the left and right lateral prefrontal cortex at 21 days after TBI. Regional cerebral tissue oxygen saturation (SctO2) in the frontal lobes was measured simultaneously by the cerebral oximeter. Significance was preset to P < 0.05. The SctO2 values before tACS were not different between hemispheres ~65%. After 15 minutes of tACS, a significant (p < 0.05) decrease in regional SctO2 was observed with the minimum at the eighth minute of 53.4 ± 3.2% and 53.4 ± 3.2% in the left and right hemispheres, respectively. At the end of the stimulation (30 minutes), the hemispheric differences in cerebral oxygen saturation became statistically insignificant again (p > 0.05). Therefore, tACS causes a significant decrease in SctO2, probably, due to neuronal activation. Our data indicate that tACS may need to be supplemented with oxygen therapy. Further research is required.
Collapse
Affiliation(s)
- Alex O Trofimov
- Department of Neurosurgery, Privolzhsky Research Medical University, Nizhny Novgorod, Russia.
- Department of Neurosurgery, Regional Hospital named after Semashko, Nizhny Novgorod, Russia.
| | - Arthem A Kopylov
- Department of Neurosurgery, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Dmitry S Martynov
- Nizhny Novgorod State Technical University named after R.E. Alekseev, Nizhny Novgorod, Russia
| | - Anna V Zorkova
- Department of Neurosurgery, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Ksenia Trofimova
- Department of Neurosurgery, Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Peter N Cheremuhin
- Department of Neurosurgery, Regional Hospital named after Semashko, Nizhny Novgorod, Russia
| | - Denis E Bragin
- Lovelace Biomedical Research Institute, Albuquerque, NM, USA
- University of New Mexico School of Medicine, Departments of Neurology and Neurosurgery, Albuquerque, NM, USA
| |
Collapse
|
84
|
Romanella SM, Roe D, Tatti E, Cappon D, Paciorek R, Testani E, Rossi A, Rossi S, Santarnecchi E. The Sleep Side of Aging and Alzheimer's Disease. Sleep Med 2021; 77:209-225. [PMID: 32912799 PMCID: PMC8364256 DOI: 10.1016/j.sleep.2020.05.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/13/2020] [Accepted: 05/19/2020] [Indexed: 01/23/2023]
Abstract
As we age, sleep patterns undergo significant modifications in micro and macrostructure, worsening cognition and quality of life. These are associated with remarkable brain changes, like deterioration in synaptic plasticity, gray and white matter, and significant modifications in hormone levels. Sleep alterations are also a core component of mild cognitive impairment (MCI) and Alzheimer's Disease (AD). AD night time is characterized by a gradual decrease in slow-wave activity and a substantial reduction of REM sleep. Sleep abnormalities can accelerate AD pathophysiology, promoting the accumulation of amyloid-β (Aβ) and phosphorylated tau. Thus, interventions that target sleep disturbances in elderly people and MCI patients have been suggested as a possible strategy to prevent or decelerate conversion to dementia. Although cognitive-behavioral therapy and pharmacological medications are still first-line treatments, despite being scarcely effective, new interventions have been proposed, such as sensory stimulation and Noninvasive Brain Stimulation (NiBS). The present review outlines the current state of the art of the relationship between sleep modifications in healthy aging and the neurobiological mechanisms underlying age-related changes. Furthermore, we provide a critical analysis showing how sleep abnormalities influence the prognosis of AD pathology by intensifying Aβ and tau protein accumulation. We discuss potential therapeutic strategies to target sleep disruptions and conclude that there is an urgent need for testing new therapeutic sleep interventions.
Collapse
Affiliation(s)
- S M Romanella
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy
| | - D Roe
- Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - E Tatti
- Department of Molecular, Cellular & Biomedical Sciences, CUNY, School of Medicine, New York, NY, USA
| | - D Cappon
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - R Paciorek
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - E Testani
- Sleep Medicine Center, Department of Neurology, Policlinico Santa Maria Le Scotte, Siena, Italy
| | - A Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - S Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - E Santarnecchi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
85
|
Wang H, Shi Z, Sun W, Zhang J, Wang J, Shi Y, Yang R, Li C, Chen D, Wu J, Gongyao G, Xu Y. Development of a Non-invasive Deep Brain Stimulator With Precise Positioning and Real-Time Monitoring of Bioimpedance. Front Neuroinform 2020; 14:574189. [PMID: 33363461 PMCID: PMC7753039 DOI: 10.3389/fninf.2020.574189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/29/2020] [Indexed: 11/21/2022] Open
Abstract
Methods by which to achieve non-invasive deep brain stimulation via temporally interfering with electric fields have been proposed, but the precision of the positioning of the stimulation and the reliability and stability of the outputs require improvement. In this study, a temporally interfering electrical stimulator was developed based on a neuromodulation technique using the interference modulation waveform produced by several high-frequency electrical stimuli to treat neurodegenerative diseases. The device and auxiliary software constitute a non-invasive neuromodulation system. The technical problems related to the multichannel high-precision output of the device were solved by an analog phase accumulator and a special driving circuit to reduce crosstalk. The function of measuring bioimpedance in real time was integrated into the stimulator to improve effectiveness. Finite element simulation and phantom measurements were performed to find the functional relations among the target coordinates, current ratio, and electrode position in the simplified model. Then, an appropriate approach was proposed to find electrode configurations for desired target locations in a detailed and realistic mouse model. A mouse validation experiment was carried out under the guidance of a simulation, and the reliability and positioning accuracy of temporally interfering electric stimulators were verified. Stimulator improvement and precision positioning solutions promise opportunities for further studies of temporally interfering electrical stimulation.
Collapse
Affiliation(s)
- Heng Wang
- School of Mechatronic Engineering, Beijing Institute of Technology, Beijing, China
| | - Zhongyan Shi
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Weiqian Sun
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Jianxu Zhang
- School of Mechatronic Engineering, Beijing Institute of Technology, Beijing, China
| | - Jing Wang
- Department of Health Management, Aerospace Center Hospital, Peking University Aerospace School of Clinical Medicine, Beijing, China
| | - Yue Shi
- Beijing Big-IQ Medical Equipment Co., Ltd., Beijing, China
| | - Ruoshui Yang
- School of Mechatronic Engineering, Beijing Institute of Technology, Beijing, China
| | - Chunlin Li
- School of Biomedical Engineering, Capital Medical University, Beijing, China
| | - Duanduan Chen
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Jinglong Wu
- School of Mechatronic Engineering, Beijing Institute of Technology, Beijing, China.,Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama, Japan
| | - Guo Gongyao
- School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Yifei Xu
- School of Life Science, Beijing Institute of Technology, Beijing, China
| |
Collapse
|
86
|
Ergo K, De Loof E, Debra G, Pastötter B, Verguts T. Failure to modulate reward prediction errors in declarative learning with theta (6 Hz) frequency transcranial alternating current stimulation. PLoS One 2020; 15:e0237829. [PMID: 33270685 PMCID: PMC7714179 DOI: 10.1371/journal.pone.0237829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 11/18/2020] [Indexed: 12/26/2022] Open
Abstract
Recent evidence suggests that reward prediction errors (RPEs) play an important role in declarative learning, but its neurophysiological mechanism remains unclear. Here, we tested the hypothesis that RPEs modulate declarative learning via theta-frequency oscillations, which have been related to memory encoding in prior work. For that purpose, we examined the interaction between RPE and transcranial Alternating Current Stimulation (tACS) in declarative learning. Using a between-subject (real versus sham stimulation group), single-blind stimulation design, 76 participants learned 60 Dutch-Swahili word pairs, while theta-frequency (6 Hz) tACS was administered over the medial frontal cortex (MFC). Previous studies have implicated MFC in memory encoding. We replicated our previous finding of signed RPEs (SRPEs) boosting declarative learning; with larger and more positive RPEs enhancing memory performance. However, tACS failed to modulate the SRPE effect in declarative learning and did not affect memory performance. Bayesian statistics supported evidence for an absence of effect. Our study confirms a role of RPE in declarative learning, but also calls for standardized procedures in transcranial electrical stimulation.
Collapse
Affiliation(s)
- Kate Ergo
- Department of Experimental Psychology, Ghent University, Ghent, Belgium
| | - Esther De Loof
- Department of Experimental Psychology, Ghent University, Ghent, Belgium
| | - Gillian Debra
- Department of Experimental Psychology, Ghent University, Ghent, Belgium
| | | | - Tom Verguts
- Department of Experimental Psychology, Ghent University, Ghent, Belgium
| |
Collapse
|
87
|
The Modulation of Cognitive Performance with Transcranial Alternating Current Stimulation: A Systematic Review of Frequency-Specific Effects. Brain Sci 2020; 10:brainsci10120932. [PMID: 33276533 PMCID: PMC7761592 DOI: 10.3390/brainsci10120932] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/20/2020] [Accepted: 11/29/2020] [Indexed: 12/21/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that allows the manipulation of intrinsic brain oscillations. Numerous studies have applied tACS in the laboratory to enhance cognitive performance. With this systematic review, we aim to provide an overview of frequency-specific tACS effects on a range of cognitive functions in healthy adults. This may help to transfer stimulation protocols to real-world applications. We conducted a systematic literature search on PubMed and Cochrane databases and considered tACS studies in healthy adults (age > 18 years) that focused on cognitive performance. The search yielded n = 109 studies, of which n = 57 met the inclusion criteria. The results indicate that theta-tACS was beneficial for several cognitive functions, including working memory, executive functions, and declarative memory. Gamma-tACS enhanced performance in both auditory and visual perception but it did not change performance in tasks of executive functions. For attention, the results were less consistent but point to an improvement in performance with alpha- or gamma-tACS. We discuss these findings and point to important considerations that would precede a transfer to real-world applications.
Collapse
|
88
|
Romanella SM, Sprugnoli G, Ruffini G, Seyedmadani K, Rossi S, Santarnecchi E. Noninvasive Brain Stimulation & Space Exploration: Opportunities and Challenges. Neurosci Biobehav Rev 2020; 119:294-319. [PMID: 32937115 PMCID: PMC8361862 DOI: 10.1016/j.neubiorev.2020.09.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/22/2020] [Accepted: 09/03/2020] [Indexed: 01/11/2023]
Abstract
As NASA prepares for longer space missions aiming for the Moon and Mars, astronauts' health and performance are becoming a central concern due to the threats associated with galactic cosmic radiation, unnatural gravity fields, and life in extreme environments. In space, the human brain undergoes functional and structural changes related to fluid shift and changes in intracranial pressure. Behavioral abnormalities, such as cognitive deficits, sleep disruption, and visuomotor difficulties, as well as psychological effects, are also an issue. We discuss opportunities and challenges of noninvasive brain stimulation (NiBS) methods - including transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES) - to support space exploration in several ways. NiBS includes safe and portable techniques already applied in a wide range of cognitive and motor domains, as well as therapeutically. NiBS could be used to enhance in-flight performance, supporting astronauts during pre-flight Earth-based training, as well as to identify biomarkers of post-flight brain changes for optimization of rehabilitation/compensatory strategies. We review these NiBS techniques and their effects on brain physiology, psychology, and cognition.
Collapse
Affiliation(s)
- S M Romanella
- Siena Brain Investigation & Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy
| | - G Sprugnoli
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Radiology Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - G Ruffini
- Neuroelectrics Corporation, Cambridge, MA, USA
| | - K Seyedmadani
- University Space Research Association NASA Johnson Space Center, Houston, TX, USA; Ann and H.J. Smead Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA
| | - S Rossi
- Siena Brain Investigation & Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - E Santarnecchi
- Siena Brain Investigation & Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
89
|
A direct comparison of the electrophysiological effects of transcranial direct and alternating current stimulation in healthy subjects. Brain Res 2020; 1747:147065. [DOI: 10.1016/j.brainres.2020.147065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 08/10/2020] [Accepted: 08/14/2020] [Indexed: 12/21/2022]
|
90
|
Haller N, Senner F, Brunoni AR, Padberg F, Palm U. Gamma transcranial alternating current stimulation improves mood and cognition in patients with major depression. J Psychiatr Res 2020; 130:31-34. [PMID: 32771678 DOI: 10.1016/j.jpsychires.2020.07.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 06/05/2020] [Accepted: 07/10/2020] [Indexed: 11/16/2022]
Abstract
Major depression is one of the most common psychiatric disorders with a high rate of treatment resistance where new treatment options are urgently warranted. One of these new options are non-invasive brain stimulation techniques like transcranial magnetic or electric stimulation. One of the latter is transcranial Alternating Current Stimulation (tACS) in various frequencies. Here, we report a case series of six patients suffering from major depression treated with tACS in gamma (40 Hz) frequency. Patients were randomized to two groups, receiving either two 10-min stimulations (group 1) or a 20-min stimulation or per day (group 2) over ten days. Hamilton Depression Rating Scale and Beck Depression Inventory decreased during treatment in both study groups by 85% and 78% (group 1), or 62% and 24% respectively (group 2). Results also showed an improvement in cognitive functions assessed by word fluency and n-back test. It is hypothesized that gamma tACS could help to synchronize disturbed frequency bands in frontal and prefrontal cortex areas and thus restore dysbalanced neural connectivity in psychiatric disorders.
Collapse
Affiliation(s)
- Nikolas Haller
- Dept. of Psychiatry and Psychotherapy, Klinikum der Universität München, Munich, Germany
| | - Fanny Senner
- Dept. of Psychiatry and Psychotherapy, Klinikum der Universität München, Munich, Germany; Institute of Psychiatric Phenomics and Genomics (IPPG), Klinikum der Universität München, Munich, Germany
| | - Andre R Brunoni
- Department and Institute of Psychiatry, Laboratory of Neurosciences (LIM-27), University of Sao Paulo, Brazil
| | - Frank Padberg
- Dept. of Psychiatry and Psychotherapy, Klinikum der Universität München, Munich, Germany
| | - Ulrich Palm
- Dept. of Psychiatry and Psychotherapy, Klinikum der Universität München, Munich, Germany; Medical Park Chiemseeblick, Bernau, Felden, Germany.
| |
Collapse
|
91
|
Giller F, Bensmann W, Mückschel M, Stock AK, Beste C. Evidence for a causal role of superior frontal cortex theta oscillations during the processing of joint subliminal and conscious conflicts. Cortex 2020; 132:15-28. [DOI: 10.1016/j.cortex.2020.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/21/2020] [Accepted: 08/10/2020] [Indexed: 01/02/2023]
|
92
|
Madrid J, Benninger DH. Non-invasive brain stimulation for Parkinson's disease: Clinical evidence, latest concepts and future goals: A systematic review. J Neurosci Methods 2020; 347:108957. [PMID: 33017643 DOI: 10.1016/j.jneumeth.2020.108957] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 08/27/2020] [Accepted: 09/18/2020] [Indexed: 12/16/2022]
Abstract
Parkinson's disease (PD) is becoming a major public-health issue in an aging population. Available approaches to treat advanced PD still have limitations; new therapies are needed. The non-invasive brain stimulation (NIBS) may offer a complementary approach to treat advanced PD by personalized stimulation. Although NIBS is not as effective as the gold-standard levodopa, recent randomized controlled trials show promising outcomes in the treatment of PD symptoms. Nevertheless, only a few NIBS-stimulation paradigms have shown to improve PD's symptoms. Current clinical recommendations based on the level of evidence are reported in Table 1 through Table 3. Furthermore, novel technological advances hold promise and may soon enable the non-invasive stimulation of deeper brain structures for longer periods.
Collapse
Affiliation(s)
- Julian Madrid
- Service of Neurology, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland.
| | - David H Benninger
- Service of Neurology, Department of Clinical Neurosciences, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland.
| |
Collapse
|
93
|
Fusco G, Fusaro M, Aglioti SM. Midfrontal-occipital Ɵ-tACS modulates cognitive conflicts related to bodily stimuli. Soc Cogn Affect Neurosci 2020; 17:91-100. [PMID: 33448297 PMCID: PMC8824600 DOI: 10.1093/scan/nsaa125] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/21/2020] [Accepted: 09/08/2020] [Indexed: 02/02/2023] Open
Abstract
Neurophysiological studies show that during tasks tapping cognitive control (like the flanker task), midfrontal theta (MFθ) oscillations are associated with conflict and error processing and neural top-down modulation of perceptual processing. What remains unknown is whether perceptual encoding of category-specific stimuli (e.g. body vs letters) used in flanker-like tasks is modulated by theta oscillations. To explore this issue, we delivered transcranial Alternating Current Stimulation (tACS) in the theta frequency band (6 Hz) over the medial frontal cortex (MFC) and the extra-striate body area (EBA), whereas healthy participants performed two variants of the classical flanker task, one with stimuli representing human hands (i.e. hand-flanker) and the other with stimuli representing coloured letters (i.e. letter-flanker). More specifically, we aimed at investigating whether θ-tACS involving a body-related area may modulate the long-range communication between neuronal populations underlying conflict monitoring and visuo-perceptual encoding of hand stimuli without affecting the conflict driven by letter stimuli. Results showed faster correct response times during θ-tACS in the hand-flanker compared with γ-tACS (40 Hz) and sham. Importantly, such an effect did not emerge in the letter-flanker. Our findings show that theta oscillations over midfrontal-occipital areas modulate bodily specific, stimulus content-driven aspects of cognitive control.
Collapse
Affiliation(s)
- Gabriele Fusco
- Correspondence should be addressed to Dr Gabriele Fusco, Department of Psychology, via dei Marsi 78, 00185, Roma, Italy. E-mail:
| | - Martina Fusaro
- Department of Psychology, Sapienza University of Rome and CLNS@SAPIENZA, Istituto Italiano di Tecnologia, Rome, Italy
- Social Neuroscience Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Salvatore Maria Aglioti
- Department of Psychology, Sapienza University of Rome and CLNS@SAPIENZA, Istituto Italiano di Tecnologia, Rome, Italy
- Social Neuroscience Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy
| |
Collapse
|
94
|
Zarubin G, Gundlach C, Nikulin V, Villringer A, Bogdan M. Transient Amplitude Modulation of Alpha-Band Oscillations by Short-Time Intermittent Closed-Loop tACS. Front Hum Neurosci 2020; 14:366. [PMID: 33100993 PMCID: PMC7500443 DOI: 10.3389/fnhum.2020.00366] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 08/10/2020] [Indexed: 12/15/2022] Open
Abstract
Non-invasive brain stimulation (NIBS) techniques such as transcranial alternating current stimulation (tACS) have recently become extensively utilized due to their potential to modulate ongoing neuronal oscillatory activity and consequently to induce cortical plasticity relevant for various cognitive functions. However, the neurophysiological basis for stimulation effects as well as their inter-individual differences is not yet understood. In the present study, we used a closed-loop electroencephalography-tACS(EEG-tACS) protocol to examine the modulation of alpha oscillations generated in occipito-parietal areas. In particular, we investigated the effects of a repeated short-time intermittent stimulation protocol (1 s in every trial) applied over the visual cortex (Cz and Oz) and adjusted according to the phase and frequency of visual alpha oscillations on the amplitude of these oscillations. Based on previous findings, we expected higher increases in alpha amplitudes for tACS applied in-phase with ongoing oscillations as compared to an application in anti-phase and this modulation to be present in low-alpha amplitude states of the visual system (eyes opened, EO) but not high (eyes closed, EC). Contrary to our expectations, we found a transient suppression of alpha power in inter-individually derived spatially specific parieto-occipital components obtained via the estimation of spatial filters by using the common spatial patterns approach. The amplitude modulation was independent of the phase relationship between the tACS signal and alpha oscillations, and the state of the visual system manipulated via closed- and open-eye conditions. It was also absent in conventionally analyzed single-channel and multi-channel data from an average parieto-occipital region. The fact that the tACS modulation of oscillations was phase-independent suggests that mechanisms driving the effects of tACS may not be explained by entrainment alone, but rather require neuroplastic changes or transient disruption of neural oscillations. Our study also supports the notion that the response to tACS is subject-specific, where the modulatory effects are shaped by the interplay between the stimulation and different alpha generators. This favors stimulation protocols as well as analysis regimes exploiting inter-individual differences, such as spatial filters to reveal otherwise hidden stimulation effects and, thereby, comprehensively induce and study the effects and underlying mechanisms of tACS.
Collapse
Affiliation(s)
- Georgy Zarubin
- Technical Informatics Department, Leipzig University, Leipzig, Germany
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Christopher Gundlach
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Institute of Psychology, University of Leipzig, Leipzig, Germany
| | - Vadim Nikulin
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Centre for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
- Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité Universitätsmedizin Berlin, Berlin, Germany
- Department of Cognitive Neurology, University Hospital Leipzig, Leipzig, Germany
- Mind Brain Body Institute at the Berlin School of Mind and Brain, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Martin Bogdan
- Technical Informatics Department, Leipzig University, Leipzig, Germany
| |
Collapse
|
95
|
Harada T, Hara M, Matsushita K, Kawakami K, Kawakami K, Anan M, Sugata H. Off-line effects of alpha-frequency transcranial alternating current stimulation on a visuomotor learning task. Brain Behav 2020; 10:e01754. [PMID: 33460319 PMCID: PMC7507357 DOI: 10.1002/brb3.1754] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 05/25/2020] [Accepted: 06/28/2020] [Indexed: 12/21/2022] Open
Abstract
INTRODUCTION It has been suggested that transcranial alternating current stimulation (tACS) at both alpha and beta frequencies promotes motor function as well as motor learning. However, limited information exists on the aftereffects of tACS on motor learning and neurophysiological profiles such as entrainment and neural plasticity in parallel. Therefore, in the present study, we examined the effect of tACS on motor learning and neurophysiological profiles using an off-line tACS condition. METHODS Thirty-three healthy participants were randomly assigned to 10 Hz, 20 Hz, or the sham group. Participants performed visuomotor learning tasks consisting of a baseline task (preadaptation task) and training task (adaptation task) to reach a target with a lever-type controller. Electroencephalography was recorded from eight locations during the learning tasks. tACS was performed between the preadaptation task and adaptation task over the left primary motor cortex for 10 min at 1 mA. RESULTS As a result, 10 Hz tACS was shown to be effective for initial angular error correction in the visuomotor learning tasks. However, there were no significant differences in neural oscillatory activities among the three groups. CONCLUSION These results suggest that initial motor learning can be facilitated even when 10 Hz tACS is applied under off-line conditions. However, neurophysiological aftereffects were recently demonstrated to be induced by tACS at individual alpha frequencies rather than fixed alpha tACS, which suggests that the neurophysiological aftereffects by fixed frequency stimulation in the present study may have been insufficient to generate changes in oscillatory neural activity.
Collapse
Affiliation(s)
- Taiki Harada
- Department of Rehabilitation, Oita University Hospital, Oita, Japan
| | - Masayuki Hara
- Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | | | - Kenji Kawakami
- Faculty of Welfare and Health Science, Oita University, Oita, Japan
| | - Keisuke Kawakami
- Faculty of Welfare and Health Science, Oita University, Oita, Japan
| | - Masaya Anan
- Faculty of Welfare and Health Science, Oita University, Oita, Japan
| | - Hisato Sugata
- Faculty of Welfare and Health Science, Oita University, Oita, Japan
| |
Collapse
|
96
|
Ozawa M, Davis P, Ni J, Maguire J, Papouin T, Reijmers L. Experience-dependent resonance in amygdalo-cortical circuits supports fear memory retrieval following extinction. Nat Commun 2020; 11:4358. [PMID: 32868768 PMCID: PMC7459312 DOI: 10.1038/s41467-020-18199-w] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 08/06/2020] [Indexed: 11/08/2022] Open
Abstract
Learned fear and safety are associated with distinct oscillatory states in the basolateral amygdala (BLA) and medial prefrontal cortex (mPFC). To determine if and how these network states support the retrieval of competing memories, we mimicked endogenous oscillatory activity through optogenetic stimulation of parvalbumin-expressing interneurons in mice during retrieval of contextual fear and extinction memories. We found that exogenously induced 4 Hz and 8 Hz oscillatory activity in the BLA exerts bi-directional control over conditioned freezing behavior in an experience- and context-specific manner, and that these oscillations have an experience-dependent ability to recruit distinct functional neuronal ensembles. At the network level we demonstrate, via simultaneous manipulation of BLA and mPFC, that experience-dependent 4 Hz resonance across BLA-mPFC circuitry supports post-extinction fear memory retrieval. Our findings reveal that post-extinction fear memory retrieval is supported by local and interregional experience-dependent resonance, and suggest novel approaches for interrogation and therapeutic manipulation of acquired fear circuitry.
Collapse
Affiliation(s)
- Minagi Ozawa
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA, USA
| | - Patrick Davis
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
- Graduate Program in Neuroscience, Graduate School of Biomedical Sciences, Tufts University, Boston, MA, USA
- Medical Scientist Training Program, Graduate School of Biomedical Sciences, Tufts University, Boston, MA, USA
- Boston Combined Residency Program (Child Neurology), Boston Children's Hospital, Boston, MA, USA
| | - Jianguang Ni
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
| | - Jamie Maguire
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
| | - Thomas Papouin
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA
- Department of Neuroscience, Washington University in St. Louis, School of Medicine, St. Louis, MO, USA
| | - Leon Reijmers
- Department of Neuroscience, School of Medicine, Tufts University, Boston, MA, USA.
| |
Collapse
|
97
|
Romanella SM, Roe D, Paciorek R, Cappon D, Ruffini G, Menardi A, Rossi A, Rossi S, Santarnecchi E. Sleep, Noninvasive Brain Stimulation, and the Aging Brain: Challenges and Opportunities. Ageing Res Rev 2020; 61:101067. [PMID: 32380212 PMCID: PMC8363192 DOI: 10.1016/j.arr.2020.101067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/26/2020] [Accepted: 04/04/2020] [Indexed: 02/06/2023]
Abstract
As we age, sleep patterns undergo severe modifications of their micro and macrostructure, with an overall lighter and more fragmented sleep structure. In general, interventions targeting sleep represent an excellent opportunity not only to maintain life quality in the healthy aging population, but also to enhance cognitive performance and, when pathology arises, to potentially prevent/slow down conversion from e.g. Mild Cognitive Impairment (MCI) to Alzheimer's Disease (AD). Sleep abnormalities are, in fact, one of the earliest recognizable biomarkers of dementia, being also partially responsible for a cascade of cortical events that worsen dementia pathophysiology, including impaired clearance systems leading to build-up of extracellular amyloid-β (Aβ) peptide and intracellular hyperphosphorylated tau proteins. In this context, Noninvasive Brain Stimulation (NiBS) techniques, such as transcranial electrical stimulation (tES) and transcranial magnetic stimulation (TMS), may help investigate the neural substrates of sleep, identify sleep-related pathology biomarkers, and ultimately help patients and healthy elderly individuals to restore sleep quality and cognitive performance. However, brain stimulation applications during sleep have so far not been fully investigated in healthy elderly cohorts, nor tested in AD patients or other related dementias. The manuscript discusses the role of sleep in normal and pathological aging, reviewing available evidence of NiBS applications during both wakefulness and sleep in healthy elderly individuals as well as in MCI/AD patients. Rationale and details for potential future brain stimulation studies targeting sleep alterations in the aging brain are discussed, including enhancement of cognitive performance, overall quality of life as well as protein clearance.
Collapse
Affiliation(s)
- Sara M Romanella
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy
| | - Daniel Roe
- Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Rachel Paciorek
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Davide Cappon
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | | | - Arianna Menardi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Padova Neuroscience Center, Department of Neuroscience, University of Padova, Padova, Italy
| | - Alessandro Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Simone Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy; Siena Robotics and Systems Lab (SIRS-Lab), Engineering and Mathematics Department, University of Siena, Siena, Italy
| | - Emiliano Santarnecchi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
98
|
Klein C, Barron AB. How experimental neuroscientists can fix the hard problem of consciousness. Neurosci Conscious 2020; 2020:niaa009. [PMID: 32695476 PMCID: PMC7362610 DOI: 10.1093/nc/niaa009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 03/30/2020] [Accepted: 04/04/2020] [Indexed: 01/06/2023] Open
Abstract
For the materialist, the hard problem is fundamentally an explanatory problem. Solving it requires explaining why the relationship between brain and experience is the way it is and not some other way. We use the tools of the interventionist theory of explanation to show how a systematic experimental project could help move beyond the hard problem. Key to this project is the development of second-order interventions and invariant generalizations. Such interventions played a crucial scientific role in untangling other scientific mysteries, and we suggest that the same will be true of consciousness. We further suggest that the capacity for safe and reliable self-intervention will play a key role in overcoming both the hard and meta-problems of consciousness. Finally, we evaluate current strategies for intervention, with an eye to how they might be improved.
Collapse
Affiliation(s)
- Colin Klein
- School of Philosophy, The Australian National University, Canberra, ACT 0200, Australia
| | - Andrew B Barron
- Department of Biological Sciences, Macquarie University, North Ryde, NSW 2109, Australia
| |
Collapse
|
99
|
Erkens J, Schulte M, Vormann M, Herrmann CS. Lacking Effects of Envelope Transcranial Alternating Current Stimulation Indicate the Need to Revise Envelope Transcranial Alternating Current Stimulation Methods. Neurosci Insights 2020; 15:2633105520936623. [PMID: 32685924 PMCID: PMC7343360 DOI: 10.1177/2633105520936623] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/28/2020] [Indexed: 12/13/2022] Open
Abstract
In recent years, several studies have reported beneficial effects of transcranial alternating current stimulation (tACS) in experiments regarding sound and speech perception. A new development in this field is envelope-tACS: The goal of this method is to improve cortical entrainment to the speech signal by stimulating with a waveform based on the speech envelope. One challenge of this stimulation method is timing; the electrical stimulation needs to be phase-aligned with the naturally occurring cortical entrainment to the auditory stimuli. Due to individual differences in anatomy and processing speed, the optimal time-lag between presentation of sound and applying envelope-tACS varies between participants. To better investigate the effects of envelope-tACS, we performed a speech comprehension task with a larger amount of time-lags than previous experiments, as well as an equal amount of sham conditions. No significant difference between optimal stimulation time-lag condition and best sham condition was found. Further investigation of the data revealed a significant difference between the positive and negative half-cycles of the stimulation conditions but not for sham. However, we also found a significant learning effect over the course of the experiment which was of comparable size to the effects of envelope-tACS found in previous auditory tACS studies. In this article, we discuss possible explanations for why our findings did not match up with those of previous studies and the issues that come with researching and developing envelope-tACS.
Collapse
Affiliation(s)
- Jules Erkens
- Experimental Psychology Lab, Department of Psychology, Cluster of Excellence 'Hearing4All', European Medical School, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| | | | | | - Christoph S Herrmann
- Experimental Psychology Lab, Department of Psychology, Cluster of Excellence 'Hearing4All', European Medical School, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany.,Research Center Neurosensory Science, Carl von Ossietzky University of Oldenburg, Oldenburg, Germany
| |
Collapse
|
100
|
Haller N, Hasan A, Padberg F, Brunelin J, da Costa Lane Valiengo L, Palm U. Gamma transcranial alternating current stimulation in patients with negative symptoms in schizophrenia: A case series. Neurophysiol Clin 2020; 50:301-304. [PMID: 32631667 DOI: 10.1016/j.neucli.2020.06.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 06/09/2020] [Accepted: 06/09/2020] [Indexed: 10/23/2022] Open
Abstract
Non-invasive transcranial brain stimulation therapies, such as transcranial direct current stimulation, have been found to improve negative symptoms in schizophrenia. Another new technique is transcranial alternating current stimulation (tACS). Here we report a series of three patient treated with twice-daily 10min prefrontal 40Hz tACS stimulation over ten days. Patients showed an improvement in the Positive and Negative Syndrome Scale, Scale for the Assessment of Negative Symptoms, and subjective well-being. Furthermore, there was an improvement in the Trail Making Test and word fluency. ytACS merits further investigation in the treatment of schizophrenia symptoms.
Collapse
Affiliation(s)
- Nikolas Haller
- Department. of Psychiatry and Psychotherapy, Klinikum der Universität München, Munich, Germany
| | - Alkomiet Hasan
- Department. of Psychiatry and Psychotherapy, Klinikum der Universität München, Munich, Germany; Klinik für Psychiatrie, Psychotherapie und Psychosomatik der Universität Augsburg, Bezirkskrankenhaus Augsburg, Medizinische Fakultät, Universität Augsburg, Augsburg, Germany
| | - Frank Padberg
- Department. of Psychiatry and Psychotherapy, Klinikum der Universität München, Munich, Germany
| | - Jerome Brunelin
- CH de le Vinatier, INSERM U 1028, CNRS UMR 5292, PSYR2 Team, Centre de recherche en neuroscience de Lyon, Université de Lyon, France
| | - Leandro da Costa Lane Valiengo
- Laboratory of Neurosciences (LIM-27), Department and Institute of Psychiatry, Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBioN), Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Ulrich Palm
- Department. of Psychiatry and Psychotherapy, Klinikum der Universität München, Munich, Germany; Medical Park Chiemseeblick, 25, Rasthausstr, 83233 Bernau-Felden, Germany.
| |
Collapse
|