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Páleník J. What does it mean for consciousness to be multidimensional? A narrative review. Front Psychol 2024; 15:1430262. [PMID: 38966739 PMCID: PMC11222411 DOI: 10.3389/fpsyg.2024.1430262] [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: 05/09/2024] [Accepted: 06/10/2024] [Indexed: 07/06/2024] Open
Abstract
A recent development in the psychological and neuroscientific study of consciousness has been the tendency to conceptualize consciousness as a multidimensional phenomenon. This narrative review elucidates the notion of dimensionality of consciousness and outlines the key concepts and disagreements on this topic through the viewpoints of several theoretical proposals. The reviewed literature is critically evaluated, and the main issues to be resolved by future theoretical and empirical work are identified: the problems of dimension selection and dimension aggregation, as well as some ethical considerations. This narrative review is seemingly the first to comprehensively overview this specific aspect of consciousness science.
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Affiliation(s)
- Julie Páleník
- First Department of Neurology, St. Anne’s University Hospital and Medical Faculty of Masaryk University, Brno, Czechia
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Cardone P, Alnagger N, Annen J, Bicego A, Gosseries O, Martial C. Psychedelics and disorders of consciousness: the current landscape and the path forward. Neurosci Conscious 2024; 2024:niae025. [PMID: 38881630 PMCID: PMC11179162 DOI: 10.1093/nc/niae025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 02/16/2024] [Accepted: 05/20/2024] [Indexed: 06/18/2024] Open
Abstract
Modern medicine has been shaken by the surge of psychedelic science that proposes a new approach to mitigate mental disorders, such as depression and post-traumatic stress disorder. Clinical trials to investigate whether psychedelic substances can treat psychiatric conditions are now underway, yet less discussion gravitates around their use in neurological disorders due to brain injury. One suggested implementation of brain-complexity enhancing psychedelics is to treat people with post-comatose disorders of consciousness (DoC). In this article, we discuss the rationale of this endeavour, examining possible outcomes of such experiments by postulating the existence of an optimal level of complexity. We consider the possible counterintuitive effects of both psychedelics and DoC on the functional connectivity of the default mode network and its possible impact on selfhood. We also elaborate on the role of computational modelling in providing complementary information to experimental studies, both contributing to our understanding of the treatment mechanisms and providing a path towards personalized medicine. Finally, we update the discourse surrounding the ethical considerations, encompassing clinical and scientific values.
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Affiliation(s)
- Paolo Cardone
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
| | - Naji Alnagger
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
| | - Jitka Annen
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Department of Data Analysis, University of Ghent, Henri Dunantlaan 1, Ghent 9000, Belgium
| | - Aminata Bicego
- Sensation and Perception Research Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
| | - Olivia Gosseries
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Sensation and Perception Research Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
| | - Charlotte Martial
- Coma Science Group, GIGA-Consciousness, University of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
- Centre du Cerveau2, University Hospital of Liège, Avenue de l'hôpital 11, Liège 4000, Belgium
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Seifi A, Hassannezhad S, Mosaddeghi-Heris R, Haji Kamanaj Olia A, Adib A, Hafeez S, Barthol C. Consciousness Recovery in Traumatic Brain Injury: A Systematic Review Comparing Modafinil and Amantadine. Clin Neuropharmacol 2023; 46:229-238. [PMID: 37962310 DOI: 10.1097/wnf.0000000000000577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
OBJECTIVES Acute traumatic brain injury is one of the most common causes of death and disability. Reduction in the level of consciousness is a significant complication that can impact morbidity. Glasgow Coma Scale (GCS) is the most widely used method of assessing the level of consciousness. Neurostimulants such as amantadine and modafinil are common pharmacologic agents that increase GCS in patients with brain trauma. This study aimed to compare the effectiveness of these 2 drugs. METHODS This systematic review obtained articles from Google Scholar, PubMed, Scopus, Embase, and MEDLINE databases. Extensive searches were conducted separately by 4 individuals in 3 stages. Ultimately, 16 clinical trials, cohort studies, case reports, and case series articles were obtained after reading the title, abstract, and full text and considering the exclusion criteria. The data of the final article were entered into the analysis table. This study was registered with PROSPERO (registration number CRD42022334409) and conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS Amantadine seems to be associated with a higher overall response rate. In contrast, modafinil is associated with the most remarkable change in GCS score during treatment. However, the number of clinical trials with high quality and sample size has not been satisfactory to compare the effectiveness of these 2 drugs and their potential side effects. CONCLUSIONS The authors recommend additional double-blind clinical trials are needed to be conducted with a larger sample size, comparing amantadine with modafinil to delineate the efficacy and adverse effects, both short and long term.
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Affiliation(s)
- Ali Seifi
- Department of Neurosurgery, UT Health, San Antonio, TX
| | - Sina Hassannezhad
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Mosaddeghi-Heris
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Ali Adib
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz, Iran
| | - Shaheryar Hafeez
- Division of Neuro Critical Care, Department of Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA
| | - Colleen Barthol
- Department of Pharmacotherapy and Pharmacy Services, University Health System of San Antonio, San Antonio, TX
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Huang Z. Temporospatial Nestedness in Consciousness: An Updated Perspective on the Temporospatial Theory of Consciousness. ENTROPY (BASEL, SWITZERLAND) 2023; 25:1074. [PMID: 37510023 PMCID: PMC10378228 DOI: 10.3390/e25071074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 06/20/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023]
Abstract
Time and space are fundamental elements that permeate the fabric of nature, and their significance in relation to neural activity and consciousness remains a compelling yet unexplored area of research. The Temporospatial Theory of Consciousness (TTC) provides a framework that links time, space, neural activity, and consciousness, shedding light on the intricate relationships among these dimensions. In this review, I revisit the fundamental concepts and mechanisms proposed by the TTC, with a particular focus on the central concept of temporospatial nestedness. I propose an extension of temporospatial nestedness by incorporating the nested relationship between the temporal circuit and functional geometry of the brain. To further unravel the complexities of temporospatial nestedness, future research directions should emphasize the characterization of functional geometry and the temporal circuit across multiple spatial and temporal scales. Investigating the links between these scales will yield a more comprehensive understanding of how spatial organization and temporal dynamics contribute to conscious states. This integrative approach holds the potential to uncover novel insights into the neural basis of consciousness and reshape our understanding of the world-brain dynamic.
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Affiliation(s)
- Zirui Huang
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA;
- Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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Neveu A, Degos V, Barberousse A. Epistemological challenges for neural correlates of consciousness: A defense of medical research on consciousness. Presse Med 2023; 52:104183. [PMID: 37839773 DOI: 10.1016/j.lpm.2023.104183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/06/2023] [Accepted: 10/09/2023] [Indexed: 10/17/2023] Open
Abstract
Recent work in the field of consciousness science has predominantly focused on the search for neural correlates of consciousness (NCC). However, despite significant technological advances in recent decades, defining NCC remains an ambitious goal in consciousness research. The main difficulty stems from an epistemological challenge known as the "Problem of coordination", which hinders or at least slows down the experimental process inherent to the study of consciousness. Fundamental research has mainly focused on a content-based conception of consciousness, often referred to as a "local" conception of consciousness. This approach suffers from the Problem of coordination and its consequences. However, an alternative, more reliable approach could be considered, namely, the global or "state-based" approach, which is grounded in clinical research on consciousness disorders.
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Affiliation(s)
- Armance Neveu
- Sciences, Normes, Démocratie, Sorbonne-Université, Paris, France.
| | - Vincent Degos
- Hôpital Pitié-Salpêtrière, APHP Sorbonne Université, Département d'Anesthésie Réanimation, Paris, France
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Ort A, Smallridge JW, Sarasso S, Casarotto S, von Rotz R, Casanova A, Seifritz E, Preller KH, Tononi G, Vollenweider FX. TMS-EEG and resting-state EEG applied to altered states of consciousness: oscillations, complexity, and phenomenology. iScience 2023; 26:106589. [PMID: 37138774 PMCID: PMC10149373 DOI: 10.1016/j.isci.2023.106589] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 12/22/2022] [Accepted: 04/03/2023] [Indexed: 05/05/2023] Open
Abstract
Exploring the neurobiology of the profound changes in consciousness induced by classical psychedelic drugs may require novel neuroimaging methods. Serotonergic psychedelic drugs such as psilocybin produce states of increased sensory-emotional awareness and arousal, accompanied by increased spontaneous electroencephalographic (EEG) signal diversity. By directly stimulating cortical tissue, the altered dynamics and propagation of the evoked EEG activity can reveal drug-induced changes in the overall brain state. We combine Transcranial Magnetic Stimulation (TMS) and EEG to reveal that psilocybin produces a state of increased chaotic brain activity which is not a result of altered complexity in the underlying causal interactions between brain regions. We also map the regional effects of psilocybin on TMS-evoked activity and identify changes in frontal brain structures that may be associated with the phenomenology of psychedelic experiences.
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Affiliation(s)
- Andres Ort
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
- Corresponding author
| | - John W. Smallridge
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
- Corresponding author
| | - Simone Sarasso
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
| | - Silvia Casarotto
- Department of Biomedical and Clinical Sciences, University of Milan, Milan, Italy
- IRCCS Fondazione Don Carlo Gnocchi Milano, Milan, Italy
| | - Robin von Rotz
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Andrea Casanova
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Erich Seifritz
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Katrin H. Preller
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin, Madison, WI, USA
| | - Franz X. Vollenweider
- Neurophenomenology of Consciousness Lab, Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zurich, Zurich, Switzerland
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Yamaki T, Hatakeyama N, Murayama T, Funakura M, Hara T, Onodera S, Ito D, Yakufujiang M, Odaki M, Oka N, Kobayashi S. Prediction of voluntary movements of the upper extremities by resting state-brain regional glucose metabolism in patients with chronic severe brain injury: A pilot study. Hum Brain Mapp 2023; 44:3158-3167. [PMID: 36929226 PMCID: PMC10171500 DOI: 10.1002/hbm.26270] [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: 12/15/2022] [Accepted: 02/24/2023] [Indexed: 03/18/2023] Open
Abstract
Confirmation of the exact voluntary movements of patients with disorder of consciousness following severe traumatic brain injury (TBI) is difficult because of the associated communication disturbances. In this pilot study, we investigated whether regional brain glucose metabolism assessed by 18 F-fluorodeoxyglucose positron emission tomography (FDG-PET) at rest could predict voluntary movement in severe TBI patients, particularly those with sufficient upper limb capacity to use communication devices. We visually and verbally instructed patients to clasp or open their hands. After video capture, three independent rehabilitation therapists determined whether the patients' movements were voluntary or involuntary. The results were compared with the standardized uptake value in the primary motor cortex, referring to the Penfield's homunculus, by resting state by FDG-PET imaged 1 year prior. Results showed that glucose uptake in the left (p = 0.0015) and right (p = 0.0121) proximal limb of the primary motor cortex, based on Penfield's homunculus on cerebral cartography, may reflect contralateral voluntary movement. Receiver operating characteristic curve analysis showed that a mean cutoff standardized uptake value of 5.47 ± 0.08 provided the best sensitivity and specificity for differentiating between voluntary and involuntary movements in each area. FDG-PET may be a useful and robust biomarker for predicting long-term recovery of motor function in severe TBI patients with disorders of consciousness.
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Affiliation(s)
- Tomohiro Yamaki
- Division of Neurosurgery, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan.,Division of Radiology, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Naoya Hatakeyama
- Division of Rehabilitation, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Takemi Murayama
- Division of Rehabilitation, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Mika Funakura
- Division of Rehabilitation, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Takuya Hara
- Division of Rehabilitation, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Shinji Onodera
- Division of Radiology, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Daisuke Ito
- Division of Neurosurgery, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Maidinamu Yakufujiang
- Division of Neurosurgery, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Masaru Odaki
- Division of Neurosurgery, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Nobuo Oka
- Division of Neurosurgery, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan.,Division of Radiology, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
| | - Shigeki Kobayashi
- Division of Neurosurgery, Rehabilitation Center for Traumatic Apallics Chiba, National Agency for Automotive Safety and Victims' Aid, 3-30-1 Isobe, Mihama-ku, Chiba, 261-0012, Japan
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Huang Z, Mashour GA, Hudetz AG. Functional geometry of the cortex encodes dimensions of consciousness. Nat Commun 2023; 14:72. [PMID: 36604428 PMCID: PMC9814511 DOI: 10.1038/s41467-022-35764-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 12/27/2022] [Indexed: 01/06/2023] Open
Abstract
Consciousness is a multidimensional phenomenon, but key dimensions such as awareness and wakefulness have been described conceptually rather than neurobiologically. We hypothesize that dimensions of consciousness are encoded in multiple neurofunctional dimensions of the brain. We analyze cortical gradients, which are continua of the brain's overarching functional geometry, to characterize these neurofunctional dimensions. We demonstrate that disruptions of human consciousness - due to pharmacological, neuropathological, or psychiatric causes - are associated with a degradation of one or more of the major cortical gradients depending on the state. Network-specific reconfigurations within the multidimensional cortical gradient space are associated with behavioral unresponsiveness of various etiologies, and these spatial reconfigurations correlate with a temporal disruption of structured transitions of dynamic brain states. In this work, we therefore provide a unifying neurofunctional framework for multiple dimensions of human consciousness in both health and disease.
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Affiliation(s)
- Zirui Huang
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA. .,Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.
| | - George A Mashour
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.,Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, 48109, USA.,Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA
| | - Anthony G Hudetz
- Department of Anesthesiology, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.,Center for Consciousness Science, University of Michigan Medical School, Ann Arbor, MI, 48109, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, 48109, USA
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Xu C, Wu W, Zheng X, Liang Q, Huang X, Zhong H, Xiao Q, Lan Y, Bai Y, Xie Q. Repetitive transcranial magnetic stimulation over the posterior parietal cortex improves functional recovery in nonresponsive patients: A crossover, randomized, double-blind, sham-controlled study. Front Neurol 2023; 14:1059789. [PMID: 36873436 PMCID: PMC9978157 DOI: 10.3389/fneur.2023.1059789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 01/18/2023] [Indexed: 02/19/2023] Open
Abstract
Background Recent studies have shown that patients with disorders of consciousness (DoC) can benefit from repetitive transcranial magnetic stimulation (rTMS) therapy. The posterior parietal cortex (PPC) is becoming increasingly important in neuroscience research and clinical treatment for DoC as it plays a crucial role in the formation of human consciousness. However, the effect of rTMS on the PPC in improving consciousness recovery remains to be studied. Method We conducted a crossover, randomized, double-blind, sham-controlled clinical study to assess the efficacy and safety of 10 Hz rTMS over the left PPC in unresponsive patients. Twenty patients with unresponsive wakefulness syndrome were recruited. The participants were randomly divided into two groups: one group received active rTMS treatment for 10 consecutive days (n = 10) and the other group received sham treatment for the same period (n = 10). After a 10-day washout period, the groups crossed over and received the opposite treatment. The rTMS protocol involved the delivery of 2000 pulses/day at a frequency of 10 Hz, targeting the left PPC (P3 electrode sites) at 90% of the resting motor threshold. The primary outcome measure was the JFK Coma Recovery Scele-Revised (CRS-R), and evaluations were conducted blindly. EEG power spectrum assessments were also conducted simultaneously before and after each stage of the intervention. Result rTMS-active treatment resulted in a significant improvement in the CRS-R total score (F = 8.443, p = 0.009) and the relative alpha power (F = 11.166, p = 0.004) compared to sham treatment. Furthermore, 8 out of 20 patients classified as rTMS responders showed improvement and evolved to a minimally conscious state (MCS) as a result of active rTMS. The relative alpha power also significantly improved in responders (F = 26.372, p = 0.002) but not in non-responders (F = 0.704, p = 0.421). No adverse effects related to rTMS were reported in the study. Conclusions This study suggests that 10 Hz rTMS over the left PPC can significantly improve functional recovery in unresponsive patients with DoC, with no reported side effects. Clinical trial registration www.ClinicalTrials.gov, identifier: NCT05187000.
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Affiliation(s)
- Chengwei Xu
- Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Wanchun Wu
- Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Xiaochun Zheng
- Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Qimei Liang
- Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Xiyan Huang
- Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Haili Zhong
- Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Qiuyi Xiao
- Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Yue Lan
- Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China
| | - Yang Bai
- Department of Rehabilitation Medicine, The First Affiliated Hospital of Nanchang University, Nanchang, China.,School of Basic Medical Sciences, Hangzhou Normal University, Hangzhou, China
| | - Qiuyou Xie
- Department of Rehabilitation Medicine, Joint Research Centre for Disorders of Consciousness, Zhujiang Hospital of Southern Medical University, Guangzhou, China
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10
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Sevenius Nilsen A, Juel BE, Thürer B, Aamodt A, Storm JF. Are we really unconscious in “unconscious” states? Common assumptions revisited. Front Hum Neurosci 2022; 16:987051. [PMID: 36277049 PMCID: PMC9581328 DOI: 10.3389/fnhum.2022.987051] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 09/08/2022] [Indexed: 12/05/2022] Open
Abstract
In the field of consciousness science, there is a tradition to categorize certain states such as slow-wave non-REM sleep and deep general anesthesia as “unconscious”. While this categorization seems reasonable at first glance, careful investigations have revealed that it is not so simple. Given that (1) behavioral signs of (un-)consciousness can be unreliable, (2) subjective reports of (un-)consciousness can be unreliable, and, (3) states presumed to be unconscious are not always devoid of reported experience, there are reasons to reexamine our traditional assumptions about “states of unconsciousness”. While these issues are not novel, and may be partly semantic, they have implications both for scientific progress and clinical practice. We suggest that focusing on approaches that provide a more pragmatic and nuanced characterization of different experimental conditions may promote clarity in the field going forward, and help us build stronger foundations for future studies.
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Affiliation(s)
- Andre Sevenius Nilsen
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
- *Correspondence: Andre Sevenius Nilsen,
| | - Bjørn E. Juel
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
- School of Medicine and Public Health, Wisconsin Institute for Sleep and Consciousness, University of Wisconsin-Madison, Madison, WI, United States
- Bjørn E. Juel,
| | - Benjamin Thürer
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
| | - Arnfinn Aamodt
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
| | - Johan F. Storm
- Department of Physiology, Institute of Basic Medicine, University of Oslo, Oslo, Norway
- Johan F. Storm,
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