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Mineur YS, Picciotto MR. How can I measure brain acetylcholine levels in vivo? Advantages and caveats of commonly used approaches. J Neurochem 2023; 167:3-15. [PMID: 37621094 PMCID: PMC10616967 DOI: 10.1111/jnc.15943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 08/26/2023]
Abstract
The neurotransmitter acetylcholine (ACh) plays a central role in the regulation of multiple cognitive and behavioral processes, including attention, learning, memory, motivation, anxiety, mood, appetite, and reward. As a result, understanding ACh dynamics in the brain is essential for elucidating the neural mechanisms underlying these processes. In vivo measurements of ACh in the brain have been challenging because of the low concentrations and rapid turnover of this neurotransmitter. Here, we review a number of techniques that have been developed to measure ACh levels in the brain in vivo. We follow this with a deeper focus on use of genetically encoded fluorescent sensors coupled with fiber photometry, an accessible technique that can be used to monitor neurotransmitter release with high temporal resolution and specificity. We conclude with a discussion of methods for analyzing fiber photometry data and their respective advantages and disadvantages. The development of genetically encoded fluorescent ACh sensors is revolutionizing the field of cholinergic signaling, allowing temporally precise measurement of ACh release in awake, behaving animals. Use of these sensors has already begun to contribute to a mechanistic understanding of cholinergic modulation of complex behaviors.
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Affiliation(s)
- Yann S. Mineur
- Department of Psychiatry, Yale University School of Medicine, 34 Park Street, 3 Floor Research, New Haven, CT 06508, USA
| | - Marina R. Picciotto
- Department of Psychiatry, Yale University School of Medicine, 34 Park Street, 3 Floor Research, New Haven, CT 06508, USA
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2
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Lima E, de Souza Neto JMR, Andrade SM. Effects of transcranial direct current stimulation on lower limb function, balance and quality of life after stroke: a systematic review and meta-analysis. Neurol Res 2023; 45:843-853. [PMID: 37183510 DOI: 10.1080/01616412.2023.2211457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/29/2023] [Indexed: 05/16/2023]
Abstract
OBJECTIVE This systematic review with meta-analysis aimed to evaluate the effectiveness of tDCS on lower limb function, balance and quality of life in stroke patients. METHODS The search included PubMed, CENTRAL, PEDro, Web of Science, SCOPUS, PsycINFO Ovid, CINAHL EBSCO, EMBASE, ScienceDirect, reference lists of relevant reviews, clinical trials registries and academic google, in June and July 2021. Randomized controlled trials were selected, which present the effect of tDCS on lower limb motor function recovery in stroke patients, comparing any type of active tDCS versus sham; parallel or crossover study design; adult patients; stimulation on the primary motor cortex; articles published in any language; without restriction of publication period. RESULTS Nineteen studies were included. The treatment with active tDCS did not improve motor function (Chi2 = 32,87, I2 = 76%, SMD = 0,36 e 95% CI -0,18-0,90). Subgroup analyzes showed a significant effect favorable to tDCS, in relation to motor function, in the acute and subacute post stroke phases. However, the quality of evidence for this outcome was very low. Regarding balance outcome, a meta-analysis showed a significant difference in favor of active tDCS, but the quality of the evidence was considered very low. As for the quality of life outcome, no statistically significant difference was found in favor of tDCS. DISCUSSION There is a lack of evidence in recommending the use of tDCS in isolation in the treatment of patients after stroke, aiming at improving motor function, balance and quality of life. However, it is possible that tDCS can be beneficial when associated with other therapies or interventions.
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Affiliation(s)
- Eloise Lima
- Aging and Neuroscience Laboratory, Federal University of Paraíba, João Pessoa, Brazil
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3
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Ayubcha C, Amanullah A, Patel KH, Teichner E, Gokhale S, Marquez-Valenzuela U, Werner TJ, Alavi A. Stroke and molecular imaging: a focus on FDG-PET. AMERICAN JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING 2023; 13:51-63. [PMID: 37214267 PMCID: PMC10193198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/23/2023] [Indexed: 05/24/2023]
Abstract
Stroke is the leading cause of disability worldwide, the second most common cause of dementia and the third leading cause of death. Though the etiology of stroke has been explored extensively, there remains open questions in the scientific and clinical study of stroke. Traditional imaging techniques, such as magnetic resonance imaging and computed tomography, have been applied extensively and remain mainstays in clinical practice. Nevertheless, positron emission tomography has proven to be a powerful molecular imaging tool in exploring the scientific aspects of neurological disease, and stroke remains an area of great interest. This review article examines the role of positron emission tomography in the study of stroke including its contributions to elaborating related pathophysiology and delving into possible clinical applications.
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Affiliation(s)
- Cyrus Ayubcha
- Harvard Medical SchoolBoston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public HealthBoston, MA, USA
| | - Aamir Amanullah
- Department of Radiology, Hospital of University of PennsylvaniaPhiladelphia, PA, USA
- Lewis Katz School of Medicine at Temple UniversityPhiladelphia, PA, USA
| | | | - Eric Teichner
- Department of Radiology, Hospital of University of PennsylvaniaPhiladelphia, PA, USA
- Thomas Jefferson UniversityPhiladelphia, PA, USA
| | - Saket Gokhale
- Department of Radiology, Hospital of University of PennsylvaniaPhiladelphia, PA, USA
- Thomas Jefferson UniversityPhiladelphia, PA, USA
| | | | - Thomas J Werner
- Department of Radiology, Hospital of University of PennsylvaniaPhiladelphia, PA, USA
| | - Abass Alavi
- Department of Radiology, Hospital of University of PennsylvaniaPhiladelphia, PA, USA
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Asadi B, Cuenca-Zaldivar JN, Nakhostin Ansari N, Ibáñez J, Herrero P, Calvo S. Brain Analysis with a Complex Network Approach in Stroke Patients Based on Electroencephalography: A Systematic Review and Meta-Analysis. Healthcare (Basel) 2023; 11:healthcare11050666. [PMID: 36900671 PMCID: PMC10000667 DOI: 10.3390/healthcare11050666] [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: 01/18/2023] [Revised: 02/18/2023] [Accepted: 02/22/2023] [Indexed: 02/26/2023] Open
Abstract
BACKGROUND AND PURPOSE Brain function can be networked, and these networks typically present drastic changes after having suffered a stroke. The objective of this systematic review was to compare EEG-related outcomes in adults with stroke and healthy individuals with a complex network approach. METHODS The literature search was performed in the electronic databases PubMed, Cochrane and ScienceDirect from their inception until October 2021. RESULTS Ten studies were selected, nine of which were cohort studies. Five of them were of good quality, whereas four were of fair quality. Six studies showed a low risk of bias, whereas the other three studies presented a moderate risk of bias. In the network analysis, different parameters such as the path length, cluster coefficient, small-world index, cohesion and functional connection were used. The effect size was small and not significant in favor of the group of healthy subjects (Hedges'g = 0.189 [-0.714, 1.093], Z = 0.582, p = 0.592). CONCLUSIONS The systematic review found that there are structural differences between the brain network of post-stroke patients and healthy individuals as well as similarities. However, there was no specific distribution network to allows us to differentiate them and, therefore, more specialized and integrated studies are needed.
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Affiliation(s)
- Borhan Asadi
- Department of Physiatry and Nursing, Faculty of Health Sciences, IIS Aragon, University of Zaragoza, C/Domingo Miral s/n, 50009 Zaragoza, Spain
| | - Juan Nicolás Cuenca-Zaldivar
- Grupo de Investigación en Fisioterapia y Dolor, Departamento de Enfermería y Fisioterapia, Facultad de Medicina y Ciencias de la Salud, Universidad de Alcalá, 28801 Alcalá de Henares, Spain
- Physical Therapy Unit, Primary Health Care Center “El Abajón”, 28231 Las Rozas de Madrid, Spain
- Research Group in Nursing and Health Care, Puerta de Hierro Health Research Institute—Segovia de Arana (IDIPHISA), 28222 Majadahonda, Spain
| | - Noureddin Nakhostin Ansari
- Research Center for War-Affected People, Tehran University of Medical Sciences, Tehran P.O. Box 14155-6559, Iran
- Department of Physiotherapy, School of Rehabilitation, Tehran University of Medical Sciences, Tehran P.O. Box 14155-6559, Iran
| | - Jaime Ibáñez
- BSICoS Group, IIS Aragón, Universidad de Zaragoza, 50018 Zaragoza, Spain
- Department of Bioengineering, Imperial College, London SW7 2AZ, UK
| | - Pablo Herrero
- Department of Physiatry and Nursing, Faculty of Health Sciences, IIS Aragon, University of Zaragoza, C/Domingo Miral s/n, 50009 Zaragoza, Spain
- Correspondence:
| | - Sandra Calvo
- Department of Physiatry and Nursing, Faculty of Health Sciences, IIS Aragon, University of Zaragoza, C/Domingo Miral s/n, 50009 Zaragoza, Spain
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Mitrović SZ, Konstantinović LM, Miler Jerković V, Dedijer-Dujović S, Djordjević OC. Extended Poststroke Rehabilitation Combined with Cerebrolysin Promotes Upper Limb Motor Recovery in Early Subacute Phase of Rehabilitation: A Randomized Clinical Study. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:medicina59020291. [PMID: 36837492 PMCID: PMC9958781 DOI: 10.3390/medicina59020291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/27/2023] [Accepted: 01/30/2023] [Indexed: 02/08/2023]
Abstract
Background and Objectives: The recovery of stroke patients with severe impairment is usually poor and limited and, unfortunately, under-investigated in clinical studies. In order to support neuroplasticity and modulate motor recovery, Cerebrolysin combined with rehabilitation treatment has proven effective in the acute stroke phase in moderate to severe motor impairment. The aim of this study was to determine the efficacy of extended poststroke rehabilitation combined with Cerebrolysin on upper limb motor recovery in subacute stroke patients with severe upper limb motor impairment. Materials and Methods: A randomized, double-blind, placebo-controlled study was conducted. Sixty patients at the early stage of severe sub-acute stroke who fulfilled all eligibility criteria were randomly assigned to the Cerebrolysin group or placebo group (𝑛 = 30 each). Both groups, after conducting three weeks of conventional rehabilitation treatment five days per week, continued to perform conventional rehabilitation treatment three times per week until 90 days of rehabilitation treatment. The primary outcome measure was the Action Research Arm Test (ARAT), and the secondary outcomes were the Fugl-Meyer Assessment-Upper Extremity (FMA-UE) motor score, Barthel index (BI), and the National Institutes of Health Stroke Scale (NIHSS). The outcome data were evaluated before, after three weeks of treatment, and on the 90th day of rehabilitation treatment, and compared within groups and between the two groups. There were no adverse events. Results: Both groups showed a significant improvement (p < 0.001) over time in BI, FMA-UE, ARAT, and NIHSS scores. Patients receiving Cerebrolysin showed more significant improvement in post-stroke upper limb motor impairment and functioning compared to the placebo group after only three weeks, and the trend was maintained after 90 days of follow up. Conclusion: Cerebrolysin delivered in the early subacute post-stroke phase added to extended conventional rehabilitation treatment is beneficial and improves motor functional recovery in patients with severe motor impairment, especially on the paretic upper extremity.
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Affiliation(s)
- Sindi Z. Mitrović
- Clinic for Rehabilitation “Dr. Miroslav Zotović”, Faculty of Medicine, University of Belgrade, Sokobanjska 13, 11000 Belgrade, Serbia
- Correspondence: (S.Z.M.); (L.M.K.)
| | - Ljubica M. Konstantinović
- Clinic for Rehabilitation “Dr. Miroslav Zotović”, Faculty of Medicine, University of Belgrade, Sokobanjska 13, 11000 Belgrade, Serbia
- Correspondence: (S.Z.M.); (L.M.K.)
| | - Vera Miler Jerković
- Innovation Center, School of Electrical Engineering, University of Belgrade, Bulevar Kralja Aleksandra 73, 11120 Belgrade, Serbia
| | - Suzana Dedijer-Dujović
- Clinic for Rehabilitation “Dr. Miroslav Zotović”, Faculty of Medicine, University of Belgrade, Sokobanjska 13, 11000 Belgrade, Serbia
| | - Olivera C. Djordjević
- Clinic for Rehabilitation “Dr. Miroslav Zotović”, Faculty of Medicine, University of Belgrade, Sokobanjska 13, 11000 Belgrade, Serbia
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Nasrallah FA, Mohamed AZ, Yap HK, Lai HS, Yeow CH, Lim JH. Effect of proprioceptive stimulation using a soft robotic glove on motor activation and brain connectivity in stroke survivors. J Neural Eng 2021; 18:066049. [PMID: 34933283 DOI: 10.1088/1741-2552/ac456c] [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] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Soft-robotic-assisted training may improve motor function during post-stroke recovery, but the underlying physiological changes are not clearly understood. We applied a single-session of intensive proprioceptive stimulation to stroke survivors using a soft robotic glove to delineate its short-term influence on brain functional activity and connectivity. APPROACH In this study, we utilized task-based and resting-state functional magnetic resonance imaging (fMRI) to characterize the changes in different brain networks following a soft robotic intervention. Nine stroke patients with hemiplegic upper limb engaged in resting-state and motor-task fMRI. The motor tasks comprised two conditions: active movement of fingers (active task) and glove-assisted active movement using a robotic glove (glove-assisted task), both with visual instruction. Each task was performed using bilateral hands simultaneously or the affected hand only. The same set of experiments was repeated following a 30-minute treatment of continuous passive motion (CPM) using a robotic glove. MAIN RESULTS On simultaneous bimanual movement, increased activation of supplementary motor area (SMA) and primary motor area (M1) were observed after CPM treatment compared to the pre-treatment condition, both in active and glove-assisted task. However, when performing the tasks solely using the affected hand, the phenomena of increased activity were not observed either in active or glove-assisted task. The comparison of the resting-state fMRI between before and after CPM showed the connectivity of the supramarginal gyrus and SMA was increased in the somatosensory network and salience network. SIGNIFICANCE This study demonstrates how passive motion exercise activates M1 and SMA in the post-stroke brain. The effective proprioceptive motor integration seen in bimanual exercise in contrast to the unilateral affected hand exercise suggests that the unaffected hemisphere might reconfigure connectivity to supplement damaged neural networks in the affected hemisphere. The somatosensory modulation rendered by the intense proprioceptive stimulation would affect the motor learning process in stroke survivors.
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Affiliation(s)
- Fatima A Nasrallah
- The University of Queensland Queensland Brain Institute, The University of Queensland, Brisbane, Saint Lucia, Queensland, 4072, AUSTRALIA
| | - Abdalla Z Mohamed
- The University of Queensland Queensland Brain Institute, The University of Queensland, Brisbane, Australia., Saint Lucia, Queensland, 4072, AUSTRALIA
| | - Hong Kai Yap
- Roceso Technologies, 83 Science Park Dr #04-01, Singapore, 118258, SINGAPORE
| | - Hwa Sen Lai
- National University of Singapore, Biomedical Engineering, Singapore, 119260, SINGAPORE
| | - Chen-Hua Yeow
- National University of Singapore, Biomedical Engineering, Singapore, 119260, SINGAPORE
| | - Jeong Hoon Lim
- School of Medicine, Medicine, National University of Singapore, NUHS Tower block level 10 1E, Kent Ridge Road, Singapore, Singapore, 119228, SINGAPORE
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7
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Upper and Lower Limb Motor Function Correlates with Ipsilesional Corticospinal Tract and Red Nucleus Structural Integrity in Chronic Stroke: A Cross-Sectional, ROI-Based MRI Study. Behav Neurol 2021; 2021:3010555. [PMID: 34804258 PMCID: PMC8601844 DOI: 10.1155/2021/3010555] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/27/2021] [Indexed: 12/31/2022] Open
Abstract
Background Structural integrity of the ipsilesional corticospinal tract (CST) is important for upper limb motor recovery after stroke. However, additional neuromechanisms associated with motor function poststroke are less well understood, especially regarding the lower limb. Objective To investigate the neural basis of upper/lower limb motor deficits poststroke by correlating measures of motor function with diffusion tensor imaging-derived indices of white matter integrity (fractional anisotropy (FA), mean diffusivity (MD)) in primary and secondary motor tracts/structures. Methods Forty-three individuals with chronic stroke (time poststroke, 64.4 ± 58.8 months) underwent a comprehensive motor assessment and MRI scanning. Correlation and multiple regression analyses were performed to examine relationships between FA/MD in a priori motor tracts/structures and motor function. Results FA in the ipsilesional CST and red nucleus (RN) was positively correlated with motor function of both the affected upper and lower limb (r = 0.36‐0.55, p ≤ 0.01), while only ipsilesional RN FA was associated with gait speed (r = 0.50). Ipsilesional CST FA explained 37.3% of the variance in grip strength (p < 0.001) and 31.5% of the variance in Arm Motricity Index (p = 0.004). Measures of MD were not predictors of motor performance. Conclusions Microstructural integrity of the ipsilesional CST is associated with both upper and lower limb motor function poststroke, but appears less important for gait speed. Integrity of the ipsilesional RN was also associated with motor performance, suggesting increased contributions from secondary motor areas may play a role in supporting chronic motor function and could become a target for interventions.
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8
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Szaflarski JP, Nenert R, Allendorfer JB, Martin AN, Amara AW, Griffis JC, Dietz A, Mark VW, Sung VW, Walker HC, Zhou X, Lindsell CJ. Intermittent Theta Burst Stimulation (iTBS) for Treatment of Chronic Post-Stroke Aphasia: Results of a Pilot Randomized, Double-Blind, Sham-Controlled Trial. Med Sci Monit 2021; 27:e931468. [PMID: 34183640 PMCID: PMC8254416 DOI: 10.12659/msm.931468] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Background Research indicates intermittent theta burst stimulation (iTBS) is a potential treatment of post-stroke aphasia. Material/Methods In this double-blind, sham-controlled trial (NCT 01512264) participants were randomized to receive 3 weeks of sham (G0), 1 week of iTBS/2 weeks of sham (G1), 2 weeks of iTBS/1 week of sham (G2), or 3 weeks of iTBS (G3). FMRI localized residual language function in the left hemisphere; iTBS was applied to the maximum fMRI activation in the residual language cortex in the left frontal lobe. FMRI and aphasia testing were conducted pre-treatment, at ≤1 week after completing treatment, and at 3 months follow-up. Results 27/36 participants completed the trial. We compared G0 to each of the individual treatment group and to all iTBS treatment groups combined (G1–3). In individual groups, participants gained (of moderate or large effect sizes; some significant at P<0.05) on the Boston Naming Test (BNT), the Semantic Fluency Test (SFT), and the Aphasia Quotient of the Western Aphasia Battery-Revised (WAB-R AQ). In G1–3, BNT, and SFT improved immediately after treatment, while the WAB-R AQ improved at 3 months. Compared to G0, the other groups showed greater fMRI activation in both hemispheres and non-significant increases in language lateralization to the left hemisphere. Changes in IFG connectivity were noted with iTBS, showing differences between time-points, with some of them correlating with the behavioral measures. Conclusions The results of this pilot trial support the hypothesis that iTBS applied to the ipsilesional hemisphere can improve aphasia and result in cortical plasticity.
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Affiliation(s)
- Jerzy P Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Rodolphe Nenert
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jane B Allendorfer
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.,Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amber N Martin
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amy W Amara
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.,Center for Exercise Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Joseph C Griffis
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Aimee Dietz
- Department of Communication Sciences and Disorders, University of Cincinnati, Cincinnati, OH, USA
| | - Victor W Mark
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Psychology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Victor W Sung
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Harrison C Walker
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Xiaohua Zhou
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, Birmingham, AL, USA
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Khan A, Chen C, Yuan K, Wang X, Mehra P, Liu Y, Tong KY. Changes in electroencephalography complexity and functional magnetic resonance imaging connectivity following robotic hand training in chronic stroke. Top Stroke Rehabil 2020; 28:276-288. [PMID: 32799771 DOI: 10.1080/10749357.2020.1803584] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Introduction: In recent years, robotic training has been utilized for recovery of motor control in patients with motor deficits. Along with clinical assessment, electrical patterns in the brain have emerged as a marker for studying changes in the brain associated with brain injury and rehabilitation. These changes mainly involve an imbalance between the two hemispheres. We aimed to study the effect of brain computer interface (BCI)-based robotic hand training on stroke subjects using clinical assessment, electroencephalographic (EEG) complexity analysis, and functional magnetic resonance imaging (fMRI) connectivity analysis. Method: Resting-state simultaneous EEG-fMRI was conducted on 14 stroke subjects before and after training who underwent 20 sessions robot hand training. Fractal dimension (FD) analysis was used to assess neuronal impairment and functional recovery using the EEG data, and fMRI connectivity analysis was performed to assess changes in the connectivity of brain networks. Results: FD results indicated a significant asymmetric difference between the ipsilesional and contralesional hemispheres before training, which was reduced after robotic hand training. Moreover, a positive correlation between interhemispheric asymmetry change for central brain region and change in Fugl Meyer Assessment (FMA) scores for upper limb was observed. Connectivity results showed a significant difference between pre-training interhemispheric connectivity and post-training interhemispheric connectivity. Moreover, the change in connectivity correlated with the change in FMA scores. Results also indicated a correlation between the increase in connectivity for motor regions and decrease in FD interhemispheric asymmetry for central brain region covering the motor area. Conclusion: In conclusion, robotic hand training significantly facilitated stroke motor recovery, and FD, along with connectivity analysis can detect neuroplasticity changes.
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Affiliation(s)
- Ahsan Khan
- Biomedical Engineering Department, The Chinese University of Hong Kong, Hong Kong, China
| | - Cheng Chen
- Biomedical Engineering Department, The Chinese University of Hong Kong, Hong Kong, China
| | - Kai Yuan
- Biomedical Engineering Department, The Chinese University of Hong Kong, Hong Kong, China
| | - Xin Wang
- Biomedical Engineering Department, The Chinese University of Hong Kong, Hong Kong, China
| | - Prabhav Mehra
- Biomedical Engineering Department, The Chinese University of Hong Kong, Hong Kong, China
| | - Yunmeng Liu
- Biomedical Engineering Department, The Chinese University of Hong Kong, Hong Kong, China
| | - Kai-Yu Tong
- Biomedical Engineering Department, The Chinese University of Hong Kong, Hong Kong, China.,Hong Kong Brain and Mind Institute, The Chinese University of Hong Kong, Hong Kong, China
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10
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Yang M, Yang Z, Yuan T, Feng W, Wang P. A Systemic Review of Functional Near-Infrared Spectroscopy for Stroke: Current Application and Future Directions. Front Neurol 2019; 10:58. [PMID: 30804877 PMCID: PMC6371039 DOI: 10.3389/fneur.2019.00058] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 01/16/2019] [Indexed: 02/05/2023] Open
Abstract
Background: Survivors of stroke often experience significant disability and impaired quality of life. The recovery of motor or cognitive function requires long periods. Neuroimaging could measure changes in the brain and monitor recovery process in order to offer timely treatment and assess the effects of therapy. A non-invasive neuroimaging technique near-infrared spectroscopy (NIRS) with its ambulatory, portable, low-cost nature without fixation of subjects has attracted extensive attention. Methods: We conducted a comprehensive literature review in order to review the use of NIRS in stroke or post-stroke patients in July 2018. NCBI Pubmed database, EMBASE database, Cochrane Library and ScienceDirect database were searched. Results: Overall, we reviewed 66 papers. NIRS has a wide range of application, including in monitoring upper limb, lower limb recovery, motor learning, cortical function recovery, cerebral hemodynamic changes, cerebral oxygenation, as well as in therapeutic method, clinical researches, and evaluation of the risk for stroke. Conclusions: This study provides a preliminary evidence of the application of NIRS in stroke patients as a monitoring, therapeutic, and research tool. Further studies could give more emphasize on the combination of NIRS with other techniques and its utility in the prevention of stroke.
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Affiliation(s)
- Muyue Yang
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai, China.,School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Zhen Yang
- Core Facility of West China Hospital, Sichuan University, Chengdu, China
| | - Tifei Yuan
- Shanghai Mental Health Centre, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Wuwei Feng
- Department of Neurology, Medical University of South Carolina, Charleston, SC, United States
| | - Pu Wang
- Department of Rehabilitation Medicine, Ruijin Hospital, Shanghai, China
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11
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Nenert R, Allendorfer JB, Martin AM, Banks C, Vannest J, Holland SK, Hart KW, Lindsell CJ, Szaflarski JP. Longitudinal fMRI study of language recovery after a left hemispheric ischemic stroke. Restor Neurol Neurosci 2018; 36:359-385. [PMID: 29782329 DOI: 10.3233/rnn-170767] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND Recovery from stroke-induced aphasia is typically protracted and involves complex functional reorganization. The relative contributions of the lesioned and non-lesioned hemispheres to this process have been examined in several cross-sectional studies but longitudinal studies involving several time-points and large numbers of subjects are scarce. OBJECTIVE The aim of this study was to address the gaps in the literature by longitudinally studying the evolution of post-stroke lateralization and localization of language-related fMRI activation in the first year after single left hemispheric ischemic stroke. METHOD Seventeen patients with stroke-induced aphasia were enrolled to undergo detailed behavioral testing and fMRI at 2, 6, 12, 26, and 52 weeks post-stroke. Matched for age, handedness and sex participants were also enrolled to visualize canonical language regions. RESULTS Behavioral results showed improvements over time for all but one of the behavioral scores (Semantic Fluency Test). FMRI results showed that the left temporal area participates in compensation for language deficits in the first year after stroke, that there is a correlation between behavioral improvement and the left cerebellar activation over time, and that there is a shift towards stronger frontal left-lateralization of the fMRI activation over the first year post-stroke. Temporary compensation observed in the initial phases of post-stroke recovery that involves the non-lesioned hemisphere may not be as important as previously postulated, since in this study the recovery was driven by activations in the left fronto-temporal regions. CONCLUSION Language recovery after left hemispheric ischemic stroke is likely driven by the previously involved in language and attention left hemispheric networks.
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Affiliation(s)
- Rodolphe Nenert
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Jane B Allendorfer
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Amber M Martin
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Christi Banks
- Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Jennifer Vannest
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Scott K Holland
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Kimberly W Hart
- Department of Emergency Medicine, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Christopher J Lindsell
- Department of Emergency Medicine, University of Cincinnati Academic Health Center, Cincinnati, OH, USA.,currently at Department of Biostatistics, Vanderbilt University, Department of Biostatistics, Nashville, TN, USA
| | - Jerzy P Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, USA.,Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
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12
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Tae WS, Ham BJ, Pyun SB, Kang SH, Kim BJ. Current Clinical Applications of Diffusion-Tensor Imaging in Neurological Disorders. J Clin Neurol 2018; 14:129-140. [PMID: 29504292 PMCID: PMC5897194 DOI: 10.3988/jcn.2018.14.2.129] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 11/02/2017] [Accepted: 11/02/2017] [Indexed: 12/11/2022] Open
Abstract
Diffusion-tensor imaging (DTI) is a noninvasive medical imaging tool used to investigate the structure of white matter. The signal contrast in DTI is generated by differences in the Brownian motion of the water molecules in brain tissue. Postprocessed DTI scalars can be used to evaluate changes in the brain tissue caused by disease, disease progression, and treatment responses, which has led to an enormous amount of interest in DTI in clinical research. This review article provides insights into DTI scalars and the biological background of DTI as a relatively new neuroimaging modality. Further, it summarizes the clinical role of DTI in various disease processes such as amyotrophic lateral sclerosis, multiple sclerosis, Parkinson's disease, Alzheimer's dementia, epilepsy, ischemic stroke, stroke with motor or language impairment, traumatic brain injury, spinal cord injury, and depression. Valuable DTI postprocessing tools for clinical research are also introduced.
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Affiliation(s)
- Woo Suk Tae
- Brain Convergence Research Center, Korea University, Seoul, Korea
| | - Byung Joo Ham
- Brain Convergence Research Center, Korea University, Seoul, Korea
- Department of Psychiatry, Korea University College of Medicine, Seoul, Korea
| | - Sung Bom Pyun
- Brain Convergence Research Center, Korea University, Seoul, Korea
- Department of Physical Medicine and Rehabilitation, Korea University College of Medicine, Seoul, Korea
| | - Shin Hyuk Kang
- Brain Convergence Research Center, Korea University, Seoul, Korea
- Department of Neurosurgery, Korea University College of Medicine, Seoul, Korea
| | - Byung Jo Kim
- Brain Convergence Research Center, Korea University, Seoul, Korea
- Department of Neurology, Korea University College of Medicine, Seoul, Korea.
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Zhang Y, Taub E, Salibi N, Uswatte G, Maudsley AA, Sheriff S, Womble B, Mark VW, Knight DC. Comparison of reproducibility of single voxel spectroscopy and whole-brain magnetic resonance spectroscopy imaging at 3T. NMR IN BIOMEDICINE 2018; 31:e3898. [PMID: 29436038 PMCID: PMC6291009 DOI: 10.1002/nbm.3898] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 12/11/2017] [Accepted: 12/26/2017] [Indexed: 05/09/2023]
Abstract
To date, single voxel spectroscopy (SVS) is the most commonly used MRS technique. SVS is relatively easy to use and provides automated and immediate access to the resulting spectra. However, it is also limited in spatial coverage. A new and very promising MRS technique allows for whole-brain MR spectroscopic imaging (WB-MRSI) with much improved spatial resolution. Establishing the reproducibility of data obtained using SVS and WB-MRSI is an important first step for using these techniques to evaluate longitudinal changes in metabolite concentration. The purpose of this study was to assess and directly compare the reproducibility of metabolite quantification at 3T using SVS and WB-MRSI in 'hand-knob' areas of motor cortices and hippocampi in healthy volunteers. Ten healthy adults were scanned using both SVS and WB-MRSI on three occasions one week apart. N-acetyl aspartate (NAA), creatine (Cr), choline (Cho) and myo-inositol (mI) were quantified using SVS and WB-MRSI with reference to both Cr and H2 O. The reproducibility of each technique was evaluated using the coefficient of variation (CV), and the correspondence between the two techniques was assessed using Pearson correlation analysis. The measured mean (range) intra-subject CVs for SVS were 5.90 (2.65-10.66)% for metabolites (i.e. NAA, Cho, mI) relative to Cr, and 8.46 (4.21-21.07)% for metabolites (NAA, Cr, Cho, mI) relative to H2 O. The mean (range) CVs for WB-MRSI were 7.56 (2.78-11.41)% for metabolites relative to Cr, and 7.79 (4.57-14.11)% for metabolites relative to H2 O. Significant positive correlations were observed between metabolites quantified using SVS and WB-MRSI techniques when the Cr but not H2 O reference was used. The results demonstrate that reproducibilities of SVS and WB-MRSI are similar for quantifying the four major metabolites (NAA, Cr, Cho, mI); both SVS and WB-MRSI exhibited good reproducibility. Our findings add reference information for choosing the appropriate 1 H-MRS technique in future studies.
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Affiliation(s)
- Yue Zhang
- Department of Psychology, University of Alabama at Birmingham, AL, USA
| | - Edward Taub
- Department of Psychology, University of Alabama at Birmingham, AL, USA
| | | | - Gitendra Uswatte
- Department of Psychology, University of Alabama at Birmingham, AL, USA
- Department of Physical Therapy, University of Alabama at Birmingham, AL, USA
| | | | | | - Brent Womble
- Department of Psychology, University of Alabama at Birmingham, AL, USA
| | - Victor W Mark
- Department of Psychology, University of Alabama at Birmingham, AL, USA
- Department of Physical Medicine and Rehabilitation, University of Alabama at Birmingham, AL, USA
- Department of Neurology, University of Alabama at Birmingham, AL, USA
| | - David C Knight
- Department of Psychology, University of Alabama at Birmingham, AL, USA
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Shuster LI. Considerations for the Use of Neuroimaging Technologies for Predicting Recovery of Speech and Language in Aphasia. AMERICAN JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2018; 27:291-305. [PMID: 29497745 DOI: 10.1044/2018_ajslp-16-0180] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 01/16/2018] [Indexed: 06/08/2023]
Abstract
PURPOSE The number of research articles aimed at identifying neuroimaging biomarkers for predicting recovery from aphasia continues to grow. Although the clinical use of these biomarkers to determine prognosis has been proposed, there has been little discussion of how this would be accomplished. This is an important issue because the best translational science occurs when translation is considered early in the research process. The purpose of this clinical focus article is to present a framework to guide the discussion of how neuroimaging biomarkers for recovery from aphasia could be implemented clinically. METHOD The genomics literature reveals that implementing genetic testing in the real-world poses both opportunities and challenges. There is much similarity between these opportunities and challenges and those related to implementing neuroimaging testing to predict recovery in aphasia. Therefore, the Center for Disease Control's model list of questions aimed at guiding the review of genetic testing has been adapted to guide the discussion of using neuroimaging biomarkers as predictors of recovery in aphasia. CONCLUSION The adapted model list presented here is a first and useful step toward initiating a discussion of how neuroimaging biomarkers of recovery could be employed clinically to provide improved quality of care for individuals with aphasia.
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Affiliation(s)
- Linda I Shuster
- Department of Speech, Language, and Hearing Sciences, Western Michigan University, Kalamazoo
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Zhang CY, Chen Y, Chen S, Kong XC, Liu Y, You CQ, Wan C, Bondzie PA, Su H, Zhang C, He FF. Evaluation of Mental Disorders Using Proton Magnetic Resonance Spectroscopy in Dialysis and Predialysis Patients. Kidney Blood Press Res 2017; 42:686-696. [PMID: 29145203 DOI: 10.1159/000484023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 08/25/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Psychological complications are prevalent in patients with chronic kidney disease (CKD). This study aimed to investigate mental disorders in stage 4-5 CKD patients, to detect metabolite concentrations in the brain by proton magnetic resonance spectroscopy (1H-MRS) and to compare the effects of different dialysis therapies on mental disorders in end-stage renal disease (ESRD). METHODS The sample population was made up of predialysis (13), hemodialysis (HD) (13), and peritoneal dialysis (PD) patients (12). We collected the baseline data of patients' age, sex, hemoglobin (Hb) and parathyroid hormone(PTH) levels. The predialysis patients served as the control group. The psychological status of the three groups was assessed using three psychological scales. 1H-MRS was used to evaluate the relative metabolite concentrations in the bilateral amygdala, hippocampus and unilateral anterior cingulated cortex (ACC). RESULTS The psychological status was better in HD patients than in predialysis and PD patients. 1H-MRS alterations were predominantly found in the ACC. Choline-containing compounds relative to creatine (Cho/Cr), myo-inositol relative to creatine (MI/Cr) and glutamate and glutamine relative to creatine (Glx/Cr) in the ACC were higher in HD patients. 1H-MRS results were correlated with the baseline data and the scores of psychological scales. CONCLUSIONS CKD patients showed different types of mental disorders as well as metabolite disturbances in the brain. The metabolite concentrations correlated with the psychological status which was better in HD than in predialytic and PD patients.
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Affiliation(s)
- Chun-Yun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ying Chen
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shan Chen
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiang-Chuang Kong
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuan Liu
- Department of Radiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chao-Qun You
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Cheng Wan
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Philip A Bondzie
- Department of Pathology and Laboratory Medicine, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Hua Su
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Chun Zhang
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fang-Fang He
- Department of Nephrology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Chiarelli AM, Zappasodi F, Di Pompeo F, Merla A. Simultaneous functional near-infrared spectroscopy and electroencephalography for monitoring of human brain activity and oxygenation: a review. NEUROPHOTONICS 2017; 4:041411. [PMID: 28840162 PMCID: PMC5566595 DOI: 10.1117/1.nph.4.4.041411] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/24/2017] [Indexed: 05/24/2023]
Abstract
Multimodal monitoring has become particularly common in the study of human brain function. In this context, combined, synchronous measurements of functional near-infrared spectroscopy (fNIRS) and electroencephalography (EEG) are getting increased interest. Because of the absence of electro-optical interference, it is quite simple to integrate these two noninvasive recording procedures of brain activity. fNIRS and EEG are both scalp-located procedures. fNIRS estimates brain hemodynamic fluctuations relying on spectroscopic measurements, whereas EEG captures the macroscopic temporal dynamics of brain electrical activity through passive voltages evaluations. The "orthogonal" neurophysiological information provided by the two technologies and the increasing interest in the neurovascular coupling phenomenon further encourage their integration. This review provides, together with an introduction regarding the principles and future directions of the two technologies, an evaluation of major clinical and nonclinical applications of this flexible, low-cost combination of neuroimaging modalities. fNIRS-EEG systems exploit the ability of the two technologies to be conducted in an environment or experimental setting and/or on subjects that are generally not suited for other neuroimaging modalities, such as functional magnetic resonance imaging, positron emission tomography, and magnetoencephalography. fNIRS-EEG brain monitoring settles itself as a useful multimodal tool for brain electrical and hemodynamic activity investigation.
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Affiliation(s)
- Antonio M. Chiarelli
- University of Illinois at Urbana Champaign, Beckman Institute, Urbana, Illinois, United States
| | - Filippo Zappasodi
- Università G. d’Annunzio, Department of Neuroscience, Imaging and Clinical Science, Chieti, Italy
- Università G. d’Annunzio, Institute for Advanced Biomedical Technologies, Chieti, Italy
| | - Francesco Di Pompeo
- Università G. d’Annunzio, Department of Neuroscience, Imaging and Clinical Science, Chieti, Italy
- Università G. d’Annunzio, Institute for Advanced Biomedical Technologies, Chieti, Italy
| | - Arcangelo Merla
- Università G. d’Annunzio, Department of Neuroscience, Imaging and Clinical Science, Chieti, Italy
- Università G. d’Annunzio, Institute for Advanced Biomedical Technologies, Chieti, Italy
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Heiss WD. Contribution of Neuro-Imaging for Prediction of Functional Recovery after Ischemic Stroke. Cerebrovasc Dis 2017; 44:266-276. [PMID: 28869961 DOI: 10.1159/000479594] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 07/18/2017] [Indexed: 12/23/2022] Open
Abstract
Prediction measures of recovery and outcome after stroke perform with only modest levels of accuracy if based only on clinical data. Prediction scores can be improved by including morphologic imaging data, where size, location, and development of the ischemic lesion is best documented by magnetic resonance imaging. In addition to the primary lesion, the involvement of fiber tracts contributes to prognosis, and consequently the use of diffusion tensor imaging (DTI) to assess primary and secondary pathways improves the prediction of outcome and of therapeutic effects. The recovery of ischemic tissue and the progression of damage are dependent on the quality of blood supply. Therefore, the status of the supplying arteries and of the collateral flow is not only crucial for determining eligibility for acute interventions, but also has an impact on the potential to integrate areas surrounding the lesion that are not typically part of a functional network into the recovery process. The changes in these functional networks after a localized lesion are assessed by functional imaging methods, which additionally show altered pathways and activated secondary centers related to residual functions and demonstrate changes in activation patterns within these networks with improved performance. These strategies in some instances record activation in secondary centers of a network, for example, also in homolog contralateral areas, which might be inhibitory to the recovery of primary centers. Such findings might have therapeutic consequences, for example, image-guided inhibitory stimulation of these areas. In the future, a combination of morphological imaging including DTI of fiber tracts and activation studies during specific tasks might yield the best information on residual function, reserve capacity, and prospects for recovery after ischemic stroke.
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Aranyi C, Opposits G, Nagy M, Berényi E, Vér C, Csiba L, Katona P, Spisák T, Emri M. Population-Level Correction of Systematic Motion Artifacts in fMRI in Patients with Ischemic Stroke. J Neuroimaging 2016; 27:397-408. [DOI: 10.1111/jon.12408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 10/17/2016] [Indexed: 01/22/2023] Open
Affiliation(s)
- Csaba Aranyi
- Department of Medical Imaging; University of Debrecen; Hungary
| | - Gábor Opposits
- Department of Medical Imaging; University of Debrecen; Hungary
| | - Marianna Nagy
- Department of Medical Imaging; University of Debrecen; Hungary
| | - Ervin Berényi
- Department of Medical Imaging; University of Debrecen; Hungary
| | - Csilla Vér
- Department of Neurology; University of Debrecen; Hungary
| | - László Csiba
- Department of Neurology; University of Debrecen; Hungary
| | - Péter Katona
- Department of Diagnostic Radiology; Kenézy Gyula County Hospital; Debrecen Hungary
| | - Tamás Spisák
- Preclinical Imaging and Biomarker Center; Gedeon Richter Plc.; Budapest Hungary
| | - Miklós Emri
- Department of Medical Imaging; University of Debrecen; Hungary
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Hatem SM, Saussez G, Della Faille M, Prist V, Zhang X, Dispa D, Bleyenheuft Y. Rehabilitation of Motor Function after Stroke: A Multiple Systematic Review Focused on Techniques to Stimulate Upper Extremity Recovery. Front Hum Neurosci 2016; 10:442. [PMID: 27679565 PMCID: PMC5020059 DOI: 10.3389/fnhum.2016.00442] [Citation(s) in RCA: 395] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Accepted: 08/18/2016] [Indexed: 12/27/2022] Open
Abstract
Stroke is one of the leading causes for disability worldwide. Motor function deficits due to stroke affect the patients' mobility, their limitation in daily life activities, their participation in society and their odds of returning to professional activities. All of these factors contribute to a low overall quality of life. Rehabilitation training is the most effective way to reduce motor impairments in stroke patients. This multiple systematic review focuses both on standard treatment methods and on innovating rehabilitation techniques used to promote upper extremity motor function in stroke patients. A total number of 5712 publications on stroke rehabilitation was systematically reviewed for relevance and quality with regards to upper extremity motor outcome. This procedure yielded 270 publications corresponding to the inclusion criteria of the systematic review. Recent technology-based interventions in stroke rehabilitation including non-invasive brain stimulation, robot-assisted training, and virtual reality immersion are addressed. Finally, a decisional tree based on evidence from the literature and characteristics of stroke patients is proposed. At present, the stroke rehabilitation field faces the challenge to tailor evidence-based treatment strategies to the needs of the individual stroke patient. Interventions can be combined in order to achieve the maximal motor function recovery for each patient. Though the efficacy of some interventions may be under debate, motor skill learning, and some new technological approaches give promising outcome prognosis in stroke motor rehabilitation.
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Affiliation(s)
- Samar M Hatem
- Physical and Rehabilitation Medicine, Brugmann University HospitalBrussels, Belgium; Systems and Cognitive Neuroscience, Institute of Neuroscience, Université Catholique de LouvainBrussels, Belgium; Faculty of Medicine and Pharmacy, Faculty of Physical Education and Physiotherapy, Vrije Universiteit BrusselBrussels, Belgium
| | - Geoffroy Saussez
- Systems and Cognitive Neuroscience, Institute of Neuroscience, Université Catholique de Louvain Brussels, Belgium
| | - Margaux Della Faille
- Systems and Cognitive Neuroscience, Institute of Neuroscience, Université Catholique de Louvain Brussels, Belgium
| | - Vincent Prist
- Physical and Rehabilitation Medicine, Centre Hospitalier de l'Ardenne Libramont, Belgium
| | - Xue Zhang
- Movement Control and Neuroplasticity Research Group, Motor Control Laboratory, Department of Kinesiology, Katholieke Universiteit Leuven Leuven, Belgium
| | - Delphine Dispa
- Systems and Cognitive Neuroscience, Institute of Neuroscience, Université Catholique de LouvainBrussels, Belgium; Physical Medicine and Rehabilitation, Cliniques Universitaires Saint-Luc, Université Catholique de LouvainBrussels, Belgium
| | - Yannick Bleyenheuft
- Systems and Cognitive Neuroscience, Institute of Neuroscience, Université Catholique de Louvain Brussels, Belgium
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Abnormal EEG Complexity and Functional Connectivity of Brain in Patients with Acute Thalamic Ischemic Stroke. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2016; 2016:2582478. [PMID: 27403202 PMCID: PMC4923597 DOI: 10.1155/2016/2582478] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 03/26/2016] [Accepted: 04/10/2016] [Indexed: 11/28/2022]
Abstract
Ischemic thalamus stroke has become a serious cardiovascular and cerebral disease in recent years. To date the existing researches mostly concentrated on the power spectral density (PSD) in several frequency bands. In this paper, we investigated the nonlinear features of EEG and brain functional connectivity in patients with acute thalamic ischemic stroke and healthy subjects. Electroencephalography (EEG) in resting condition with eyes closed was recorded for 12 stroke patients and 11 healthy subjects as control group. Lempel-Ziv complexity (LZC), Sample Entropy (SampEn), and brain network using partial directed coherence (PDC) were calculated for feature extraction. Results showed that patients had increased mean LZC and SampEn than the controls, which implied the stroke group has higher EEG complexity. For the brain network, the stroke group displayed a trend of weaker cortical connectivity, which suggests a functional impairment of information transmission in cortical connections in stroke patients. These findings suggest that nonlinear analysis and brain network could provide essential information for better understanding the brain dysfunction in the stroke and assisting monitoring or prognostication of stroke evolution.
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Julkunen P, Määttä S, Säisänen L, Kallioniemi E, Könönen M, Jäkälä P, Vanninen R, Vaalto S. Functional and structural cortical characteristics after restricted focal motor cortical infarction evaluated at chronic stage - Indications from a preliminary study. Clin Neurophysiol 2016; 127:2775-2784. [PMID: 27417053 DOI: 10.1016/j.clinph.2016.05.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 05/04/2016] [Accepted: 05/10/2016] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To assess the inter-hemispheric differences in neuronal function and structure of the motor cortex in a small group of chronic stroke patients having suffered a restricted ischemic lesion affecting hand motor representation. GABAergic intracortical inhibition, known to be affected by stroke lesion, was also investigated. METHODS Eight patients exhibiting little or no motor impairment were studied using transcranial magnetic stimulation (TMS) and diffusion weighted imaging (DWI) >15months from diagnosis. Resting motor threshold (MT) for 50μV and 2mV motor evoked potentials, and short-interval intracortical inhibition (SICI) were measured from hand muscles. Apparent diffusion coefficients (ADCs) were analyzed from the DWI for the primary motor cortex (M1), the supplementary motor area (SMA) and thalamus for reflecting changes in neuronal organization. RESULTS The MTs did not differ between the affected (AH) and unaffected hemisphere (UH) in 50μV responses, while the MTs for 2mV responses were higher (p=0.018) in AH. SICI was weakened in AH (p=0.008). ADCs were higher in the affected M1 compared to the unaffected M1 (p=0.018) while there were no inter-hemispheric differences in SMA or thalamus. CONCLUSIONS Inter-hemispheric asymmetry and neuronal organization demonstrated abnormalities in the M1. However, no confident inference can be made whether the observed alterations in neurophysiological and imaging measures have causal role for motor rehabilitation in these patients. SIGNIFICANCE Neurophysiological changes persist and are detectable using TMS years after stroke even though clinical symptoms have normalized.
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Affiliation(s)
- Petro Julkunen
- Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Applied Physics, University of Eastern Finland, Kuopio, Finland.
| | - Sara Määttä
- Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Clinical Neurophysiology, Institute of Clinical Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Laura Säisänen
- Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Clinical Neurophysiology, Institute of Clinical Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Elisa Kallioniemi
- Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Mervi Könönen
- Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland; Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland
| | - Pekka Jäkälä
- Department of Neurology, Kuopio University Hospital, Kuopio, Finland; Department of Neurology, Institute of Clinical Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Ritva Vanninen
- Department of Clinical Radiology, Kuopio University Hospital, Kuopio, Finland; Department of Clinical Radiology, Institute of Clinical Medicine, Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland
| | - Selja Vaalto
- Department of Clinical Neurophysiology, Helsinki University Hospital, Helsinki, Finland; Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland
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Effects of vagus nerve stimulation on cognitive functioning in rats with cerebral ischemia reperfusion. J Transl Med 2016; 14:101. [PMID: 27118204 PMCID: PMC4847184 DOI: 10.1186/s12967-016-0858-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 04/10/2016] [Indexed: 11/28/2022] Open
Abstract
Background Vagus nerve stimulation (VNS) has become the most common non-pharmacological treatment for intractable drug-resistant epilepsy. However, the contribution of VNS to neurological rehabilitation following stroke has not been thoroughly examined. Therefore, we investigated the specific role of acute VNS in the recovery of cognitive functioning and the possible mechanisms involved using a cerebral ischemia/reperfusion (I/R) injury model in rats. Methods The I/R-related injury was modeled using occlusion and reperfusion of the middle cerebral artery (MCAO/R) in Sprague–Dawley rats. VNS was concurrently applied to the vagus nerve using a stimulation intensity of 1 mA at a fixed frequency of 20 Hz with a 0.4-ms bipolar pulse width. The stimulation duration and inter-train interval were both 3 s. Next, Morris water maze and shuttle-box behavioral experiments were conducted to assess the effects of VNS on the recovery of learning, memory, and inhibitory avoidance following I/R injury. Intracerebroventricular injection of N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine hydrochloride (DSP-4), a selective neurotoxin for noradrenergic neurons, was used to evaluate the role of norepinephrine (NE) as a mediator of therapeutic effects of VNS on cognitive recovery. Results Compared with the MCAO/R group, the VNS+MCAO/R group had improved spatial memory as indicated by swimming path lengths and escape latencies in the Morris water maze, and fear memory, as indicated by the avoidance conditioned response rate, mean shock duration, and avoidance time in shuttle-box behavior experiments. Compared with the VNS+MCAO/R group, the DSP-4+VNS+MCAO/R group, which had reduced NE levels in cortical and hippocampal brain regions, showed a reversal of the VNS-induced benefits on spatial and fear memory performance. Conclusions VNS improves spatial and fear memory in a rat model of MCAO/R injury. However, a reduction in NE from the administration of DSP-4 blocks these protective effects, suggesting that NE may contribute to the influence exhibited by VNS on memory performance in rats with cerebral I/R-related injury.
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Cerebral Glucose Metabolism and Sedation in Brain-injured Patients: A Microdialysis Study. J Neurosurg Anesthesiol 2016; 27:187-93. [PMID: 25144502 DOI: 10.1097/ana.0000000000000107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND Disturbed brain metabolism is a signature of primary damage and/or precipitates secondary injury processes after severe brain injury. Sedatives and analgesics target electrophysiological functioning and are as such well-known modulators of brain energy metabolism. Still unclear, however, is how sedatives impact glucose metabolism and whether they differentially influence brain metabolism in normally active, healthy brain and critically impaired, injured brain. We therefore examined and compared the effects of anesthetic drugs under both critical (<1 mmol/L) and noncritical (>1 mmol/L) extracellular brain glucose levels. METHODS We performed an explorative, retrospective analysis of anesthetic drug administration and brain glucose concentrations, obtained by bedside microdialysis, in 19 brain-injured patients. RESULT Our investigations revealed an inverse linear correlation between brain glucose and both the concentration of extracellular glutamate (Pearson r=-0.58, P=0.01) and the lactate/glucose ratio (Pearson r=-0.55, P=0.01). For noncritical brain glucose levels, we observed a positive linear correlation between midazolam dose and brain glucose (P<0.05). For critical brain glucose levels, extracellular brain glucose was unaffected by any type of sedative. CONCLUSIONS These findings suggest that the use of anesthetic drugs may be of limited value in attempts to influence brain glucose metabolism in injured brain tissue.
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Paggiaro A, Birbaumer N, Cavinato M, Turco C, Formaggio E, Del Felice A, Masiero S, Piccione F. Magnetoencephalography in Stroke Recovery and Rehabilitation. Front Neurol 2016; 7:35. [PMID: 27065338 PMCID: PMC4815903 DOI: 10.3389/fneur.2016.00035] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Accepted: 03/04/2016] [Indexed: 01/01/2023] Open
Abstract
Magnetoencephalography (MEG) is a non-invasive neurophysiological technique used to study the cerebral cortex. Currently, MEG is mainly used clinically to localize epileptic foci and eloquent brain areas in order to avoid damage during neurosurgery. MEG might, however, also be of help in monitoring stroke recovery and rehabilitation. This review focuses on experimental use of MEG in neurorehabilitation. MEG has been employed to detect early modifications in neuroplasticity and connectivity, but there is insufficient evidence as to whether these methods are sensitive enough to be used as a clinical diagnostic test. MEG has also been exploited to derive the relationship between brain activity and movement kinematics for a motor-based brain–computer interface. In the current body of experimental research, MEG appears to be a powerful tool in neurorehabilitation, but it is necessary to produce new data to confirm its clinical utility.
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Affiliation(s)
- Andrea Paggiaro
- Laboratory of Neurophysiology and Magnetoencephalography, Department of Neurophysiology, Institute of Care and Research, S.Camillo Hospital Foundation , Venice , Italy
| | - Niels Birbaumer
- Laboratory of Neurophysiology and Magnetoencephalography, Department of Neurophysiology, Institute of Care and Research, S.Camillo Hospital Foundation, Venice, Italy; Institute of Medical Psychology and Behavioral Neurobiology, University of Tübingen, Tübingen, Germany
| | - Marianna Cavinato
- Laboratory of Neurophysiology and Magnetoencephalography, Department of Neurophysiology, Institute of Care and Research, S.Camillo Hospital Foundation , Venice , Italy
| | - Cristina Turco
- Laboratory of Neurophysiology and Magnetoencephalography, Department of Neurophysiology, Institute of Care and Research, S.Camillo Hospital Foundation , Venice , Italy
| | - Emanuela Formaggio
- Laboratory of Neurophysiology and Magnetoencephalography, Department of Neurophysiology, Institute of Care and Research, S.Camillo Hospital Foundation , Venice , Italy
| | - Alessandra Del Felice
- Section of Rehabilitation, Department of Neuroscience, University of Padova , Padova , Italy
| | - Stefano Masiero
- Section of Rehabilitation, Department of Neuroscience, University of Padova , Padova , Italy
| | - Francesco Piccione
- Laboratory of Neurophysiology and Magnetoencephalography, Department of Neurophysiology, Institute of Care and Research, S.Camillo Hospital Foundation , Venice , Italy
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Dipietro L, Poizner H, Krebs HI. Spatiotemporal dynamics of online motor correction processing revealed by high-density electroencephalography. J Cogn Neurosci 2014; 26:1966-80. [PMID: 24564462 PMCID: PMC4692805 DOI: 10.1162/jocn_a_00593] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The ability to control online motor corrections is key to dealing with unexpected changes arising in the environment with which we interact. How the CNS controls online motor corrections is poorly understood, but evidence has accumulated in favor of a submovement-based model in which apparently continuous movement is segmented into distinct submovements. Although most studies have focused on submovements' kinematic features, direct links with the underlying neural dynamics have not been extensively explored. This study sought to identify an electroencephalographic signature of submovements. We elicited kinematic submovements using a double-step displacement paradigm. Participants moved their wrist toward a target whose direction could shift mid-movement with a 50% probability. Movement kinematics and cortical activity were concurrently recorded with a low-friction robotic device and high-density electroencephalography. Analysis of spatiotemporal dynamics of brain activation and its correlation with movement kinematics showed that the production of each kinematic submovement was accompanied by (1) stereotyped topographic scalp maps and (2) frontoparietal ERPs time-locked to submovements. Positive ERP peaks from frontocentral areas contralateral to the moving wrist preceded kinematic submovement peaks by 220-250 msec and were followed by positive ERP peaks from contralateral parietal areas (140-250 msec latency, 0-80 msec before submovement peaks). Moreover, individual subject variability in the latency of frontoparietal ERP components following the target shift significantly predicted variability in the latency of the corrective submovement. Our results are in concordance with evidence for the intermittent nature of continuous movement and elucidate the timing and role of frontoparietal activations in the generation and control of corrective submovements.
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Heiss WD, Kidwell CS. Imaging for prediction of functional outcome and assessment of recovery in ischemic stroke. Stroke 2014; 45:1195-201. [PMID: 24595589 DOI: 10.1161/strokeaha.113.003611] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Wolf-Dieter Heiss
- From the Max Planck Institute for Neurological Research, Cologne, Germany (W.-D.H.); and Departments of Neurology and Medical Imaging, University of Arizona, Tucson (C.S.K.)
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Beaulieu LD, Massé-Alarie H, Brouwer B, Schneider C. Brain control of volitional ankle tasks in people with chronic stroke and in healthy individuals. J Neurol Sci 2013; 338:148-55. [PMID: 24433928 DOI: 10.1016/j.jns.2013.12.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 12/04/2013] [Accepted: 12/23/2013] [Indexed: 11/28/2022]
Abstract
This study explored the relationships between motor cortical control of ankle dorsiflexors and clinical impairments of volitional ankle dorsiflexion in people with chronic stroke. Eighteen persons with stroke and 14 controls were evaluated. Clinical tools were used to assess ankle dorsiflexion amplitude and isometric strength. Transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) tested the functional integrity of cortical circuits controlling the tibialis anterior (TA). All clinical scores and most TMS outcomes were impaired in people with chronic stroke. The lower clinical scores were related to the reduction of the strength of corticospinal projections onto spinal motoneurons. Concurrent TMS and clinical testing in chronic stroke provided original data demonstrating relationships between the integrity of cortical and corticospinal components of TA motor control and volitional ankle tasks. Our study proposes that volitional ankle mobilization in chronic stroke may be explained by the residual abnormal M1 circuits which may be responsive for rehabilitation intervention. This should be confirmed in longitudinal studies with larger samples to determine whether TMS outcomes associated with lower limb muscles are predictive of clinical changes or vice versa.
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Affiliation(s)
- L D Beaulieu
- Axe neurosciences du Centre de recherche du CHU de Québec, Québec, QC, Canada
| | - H Massé-Alarie
- Axe neurosciences du Centre de recherche du CHU de Québec, Québec, QC, Canada
| | - B Brouwer
- School of Rehabilitation Therapy, Faculty of Health Sciences, Queen's University, ONT, Canada
| | - C Schneider
- Axe neurosciences du Centre de recherche du CHU de Québec, Québec, QC, Canada; Department of Rehabilitation, Faculty of Medicine, Université Laval, Québec, QC, Canada.
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Shah PP, Szaflarski JP, Allendorfer J, Hamilton RH. Induction of neuroplasticity and recovery in post-stroke aphasia by non-invasive brain stimulation. Front Hum Neurosci 2013; 7:888. [PMID: 24399952 PMCID: PMC3870921 DOI: 10.3389/fnhum.2013.00888] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 12/05/2013] [Indexed: 11/13/2022] Open
Abstract
Stroke victims tend to prioritize speaking, writing, and walking as the three most important rehabilitation goals. Of note is that two of these goals involve communication. This underscores the significance of developing successful approaches to aphasia treatment for the several hundred thousand new aphasia patients each year and over 1 million stroke survivors with chronic aphasia in the U.S. alone. After several years of growth as a research tool, non-invasive brain stimulation (NBS) is gradually entering the arena of clinical aphasiology. In this review, we first examine the current state of knowledge of post-stroke language recovery including the contributions from the dominant and non-dominant hemispheres. Next, we briefly discuss the methods and the physiologic basis of the use of inhibitory and excitatory repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) as research tools in patients who experience post-stroke aphasia. Finally, we provide a critical review of the most influential evidence behind the potential use of these two brain stimulation methods as clinical rehabilitative tools.
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Affiliation(s)
- Priyanka P Shah
- Department of Neurology, University of Pennsylvania Philadelphia, PA, USA ; Laboratory for Cognition and Neural Stimulation, Center for Cognitive Neuroscience, University of Pennsylvania Philadelphia, PA, USA
| | - Jerzy P Szaflarski
- Department of Neurology, University of Alabama at Birmingham Birmingham, AL, USA
| | - Jane Allendorfer
- Department of Neurology, University of Alabama at Birmingham Birmingham, AL, USA
| | - Roy H Hamilton
- Department of Neurology, University of Pennsylvania Philadelphia, PA, USA ; Laboratory for Cognition and Neural Stimulation, Center for Cognitive Neuroscience, University of Pennsylvania Philadelphia, PA, USA
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Talukdar T, Moore JH, Diamond SG. Continuous correction of differential path length factor in near-infrared spectroscopy. JOURNAL OF BIOMEDICAL OPTICS 2013; 18:56001. [PMID: 23640027 PMCID: PMC4023650 DOI: 10.1117/1.jbo.18.5.056001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In continuous-wave near-infrared spectroscopy (CW-NIRS), changes in the concentration of oxyhemoglobin and deoxyhemoglobin can be calculated by solving a set of linear equations from the modified Beer-Lambert Law. Cross-talk error in the calculated hemodynamics can arise from inaccurate knowledge of the wavelength-dependent differential path length factor (DPF). We apply the extended Kalman filter (EKF) with a dynamical systems model to calculate relative concentration changes in oxy- and deoxyhemoglobin while simultaneously estimating relative changes in DPF. Results from simulated and experimental CW-NIRS data are compared with results from a weighted least squares (WLSQ) method. The EKF method was found to effectively correct for artificially introduced errors in DPF and to reduce the cross-talk error in simulation. With experimental CW-NIRS data, the hemodynamic estimates from EKF differ significantly from the WLSQ (p < 0.001). The cross-correlations among residuals at different wavelengths were found to be significantly reduced by the EKF method compared to WLSQ in three physiologically relevant spectral bands 0.04 to 0.15 Hz, 0.15 to 0.4 Hz and 0.4 to 2.0 Hz (p < 0.001). This observed reduction in residual cross-correlation is consistent with reduced cross-talk error in the hemodynamic estimates from the proposed EKF method.
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Affiliation(s)
- Tanveer Talukdar
- Thayer School of Engineering at Dartmouth, Hanover, NH 03755, USA.
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Tarapore PE, Findlay AM, Lahue SC, Lee H, Honma SM, Mizuiri D, Luks TL, Manley GT, Nagarajan SS, Mukherjee P. Resting state magnetoencephalography functional connectivity in traumatic brain injury. J Neurosurg 2013; 118:1306-16. [PMID: 23600939 DOI: 10.3171/2013.3.jns12398] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Traumatic brain injury (TBI) is one of the leading causes of morbidity worldwide. One mechanism by which blunt head trauma may disrupt normal cognition and behavior is through alteration of functional connectivity between brain regions. In this pilot study, the authors applied a rapid automated resting state magnetoencephalography (MEG) imaging technique suitable for routine clinical use to test the hypothesis that there is decreased functional connectivity in patients with TBI compared with matched controls, even in cases of mild TBI. Furthermore, they posit that these abnormal reductions in MEG functional connectivity can be detected even in TBI patients without specific evidence of traumatic lesions on 3-T MR images. Finally, they hypothesize that the reductions of functional connectivity can improve over time across serial MEG scans during recovery from TBI. METHODS Magnetoencephalography maps of functional connectivity in the alpha (8- to 12-Hz) band from 21 patients who sustained a TBI were compared with those from 18 age- and sex-matched controls. Regions of altered functional connectivity in each patient were detected in automated fashion through atlas-based registration to the control database. The extent of reduced functional connectivity in the patient group was tested for correlations with clinical characteristics of the injury as well as with findings on 3-T MRI. Finally, the authors compared initial connectivity maps with 2-year follow-up functional connectivity in a subgroup of 5 patients with TBI. RESULTS Fourteen male and 7 female patients (17-53 years old, median 29 years) were enrolled. By Glasgow Coma Scale (GCS) criteria, 11 patients had mild, 1 had moderate, and 3 had severe TBI, and 6 had no GCS score recorded. On 3-T MRI, 16 patients had abnormal findings attributable to the trauma and 5 had findings in the normal range. As a group, the patients with TBI had significantly lower functional connectivity than controls (p < 0.01). Three of the 5 patients with normal findings on 3-T MRI showed regions of abnormally reduced MEG functional connectivity. No significant correlations were seen between extent of functional disconnection and injury severity or posttraumatic symptoms (p > 0.05). In the subgroup undergoing 2-year follow-up, the second MEG scan demonstrated a significantly lower percentage of voxels with decreased connectivity (p < 0.05) than the initial MEG scan. CONCLUSIONS A rapid automated resting-state MEG imaging technique demonstrates abnormally decreased functional connectivity that may persist for years after TBI, including cases classified as "mild" by GCS criteria. Disrupted MEG connectivity can be detected even in some patients with normal findings on 3-T MRI. Analysis of follow-up MEG scans in a subgroup of patients shows that, over time, the abnormally reduced connectivity can improve, suggesting neuroplasticity during the recovery from TBI. Resting state MEG deserves further investigation as a prognostic and predictive biomarker for TBI.
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Affiliation(s)
- Phiroz E Tarapore
- Department of Neurological Surgery, University of California, San Francisco, California 94107-0946, USA
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Szaflarski JP, Allendorfer JB, Banks C, Vannest J, Holland SK. Recovered vs. not-recovered from post-stroke aphasia: the contributions from the dominant and non-dominant hemispheres. Restor Neurol Neurosci 2013; 31:347-60. [PMID: 23482065 PMCID: PMC3701454 DOI: 10.3233/rnn-120267] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Several adult studies have documented the importance of the peri-stroke areas to aphasia recovery. But, studies examining the differences in patterns of cortical participation in language comprehension in patients who have (LMCA-R) or have not recovered (LMCA-NR) from left middle cerebral artery infarction have not been performed up to date. METHODS In this study, we compare cortical correlates of language comprehension using fMRI and semantic decision/tone decision task in 9 LMCA-R and 18 LMCA-NR patients matched at the time of stroke for age and handedness. We examine the cortical correlates of language performance by correlating intra- and extra-scanner measures of linguistic performance with fMRI activation and stroke volumes. RESULTS Our analyses show that LMCA-R at least 1 year after stroke show a return to typical fMRI language activation patterns and that there is a compensatory reorganization of language function in LMCA-NR patients with shifts to the right hemispheric brain regions. Further, with increasing strength of the left-hemispheric fMRI signal shift there are associated improvements in performance as tested with standardized linguistic measures. A negative correlation between the size of the stroke and performance on some of the linguistic tests is also observed. CONCLUSIONS This right-hemispheric shift as a mechanism of post-stroke recovery in adults appears to be an ineffective mode of language function recovery with increasing right-hemispheric shift associated with lower language performance. Thus, normalization of the post-stroke language activation patterns is needed for better language performance while shifts of the activation patterns to the non-dominant (right) hemisphere and/or large stroke size are associated with decreased linguistic abilities after stroke.
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Affiliation(s)
- Jerzy P. Szaflarski
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
- Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Jane B. Allendorfer
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Christi Banks
- Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, OH, USA
| | - Jennifer Vannest
- Department of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
- Pediatric Neuroimaging Research Consortium, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
| | - Scott K. Holland
- Department of Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
- Department of Radiology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
- Pediatric Neuroimaging Research Consortium, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
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Transcranial magnetic stimulation for the prediction and enhancement of rehabilitation treatment effects. J Neurol Phys Ther 2012; 36:87-93. [PMID: 22592064 DOI: 10.1097/npt.0b013e3182564d26] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In this update on rehabilitation technology, transcranial magnetic stimulation (TMS), a technique that allows noninvasive stimulation of the brain, is examined. The background and basic principles of TMS are reviewed, and its usefulness as a tool to inform and possibly augment the rehabilitation process is discussed. The three main paradigms by which TMS is applied-physiological measurement, disruption/virtual lesion studies, and modulation of cortical excitability-are discussed relative to the types of scientific information each paradigm can provide and their potential clinical usefulness in the future. One of the more exciting prospects is that, when combined with rehabilitation training, TMS modulation of cortical excitability could potentially enhance the effects of rehabilitation and lead to greater levels of recovery than are currently attainable with rehabilitation alone. It is concluded that current studies must focus on the mechanisms of recovery based on the specific structures and processes affected by the disorder and the neural effects of specific rehabilitation interventions in order for the potential of TMS-augmented rehabilitation to be realized.
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Sztriha LK, O'Gorman RL, Modo M, Barker GJ, Williams SCR, Kalra L. Monitoring brain repair in stroke using advanced magnetic resonance imaging. Stroke 2012; 43:3124-31. [PMID: 23010674 DOI: 10.1161/strokeaha.111.649244] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Laszlo K Sztriha
- Department of clinical Neuroscience, Institute of Psychiatry, King's College London, Denmark Hill, SE5 8AF, London, UK.
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Allendorfer JB, Storrs JM, Szaflarski JP. Changes in white matter integrity follow excitatory rTMS treatment of post-stroke aphasia. Restor Neurol Neurosci 2012; 30:103-13. [PMID: 22233802 DOI: 10.3233/rnn-2011-0627] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE In this study, we examine whether an excitatory repetitive transcranial magnetic stimulation (rTMS) protocol called intermittent theta burst stimulation (iTBS) applied to the affected left hemisphere leads to changes in white matter fractional anisotropy (FA). METHODS Diffusion tensor imaging (DTI) data were collected in 8 aphasic stroke patients before and after 10 daily iTBS treatments. Alignment of structural and DTI data and derivation of diffusion index maps were performed using Analysis of Functional NeuroImages software followed by Tract-Based Spatial Statistics using FMRIB Software Library. Paired t-tests were performed to compare pre- to post-rTMS changes in FA. RESULTS There were significant (p < 0.001) left-hemispheric FA increases near the inferior and superior frontal gyri and anterior corpus callosum. FA also increased in the right midbrain and bilaterally near temporal, parietal and posterior cingulate regions. FA decreased bilaterally near the fusiform gyrus and in left cerebellum. CONCLUSIONS Overall, left-hemispheric regions that showed increased FA corresponded to areas previously shown to have increases in fMRI language activation after iTBS. The increased white matter integrity near the stimulation sites may reflect improvements in cortical function mediated by excitatory rTMS through its ability to facilitate synaptic connections.
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Affiliation(s)
- Jane B Allendorfer
- Department of Neurology, University of Cincinnati Academic Health Center, Cincinnati, OH, USA.
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Maladaptive plasticity for motor recovery after stroke: mechanisms and approaches. Neural Plast 2012; 2012:359728. [PMID: 22792492 PMCID: PMC3391905 DOI: 10.1155/2012/359728] [Citation(s) in RCA: 135] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Revised: 05/01/2012] [Accepted: 05/27/2012] [Indexed: 01/12/2023] Open
Abstract
Many studies in human and animal models have shown that neural plasticity compensates for the loss of motor function after stroke. However, neural plasticity concerning compensatory movement, activated ipsilateral motor projections and competitive interaction after stroke contributes to maladaptive plasticity, which negatively affects motor recovery. Compensatory movement on the less-affected side helps to perform self-sustaining activity but also creates an inappropriate movement pattern and ultimately limits the normal motor pattern. The activated ipsilateral motor projections after stroke are unable to sufficiently support the disruption of the corticospinal motor projections and induce the abnormal movement linked to poor motor ability. The competitive interaction between both hemispheres induces abnormal interhemispheric inhibition that weakens motor function in stroke patients. Moreover, widespread disinhibition increases the risk of competitive interaction between the hand and the proximal arm, which results in an incomplete motor recovery. To minimize this maladaptive plasticity, rehabilitation programs should be selected according to the motor impairment of stroke patients. Noninvasive brain stimulation might also be useful for correcting maladaptive plasticity after stroke. Here, we review the underlying mechanisms of maladaptive plasticity after stroke and propose rehabilitation approaches for appropriate cortical reorganization.
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Gwin JT, Ferris DP. An EEG-based study of discrete isometric and isotonic human lower limb muscle contractions. J Neuroeng Rehabil 2012; 9:35. [PMID: 22682644 PMCID: PMC3476535 DOI: 10.1186/1743-0003-9-35] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 06/09/2012] [Indexed: 11/28/2022] Open
Abstract
Background Electroencephalography (EEG) combined with independent component analysis enables functional neuroimaging in dynamic environments including during human locomotion. This type of functional neuroimaging could be a powerful tool for neurological rehabilitation. It could enable clinicians to monitor changes in motor control related cortical dynamics associated with a therapeutic intervention, and it could facilitate noninvasive electrocortical control of devices for assisting limb movement to stimulate activity dependent plasticity. Understanding the relationship between electrocortical dynamics and muscle activity will be helpful for incorporating EEG-based functional neuroimaging into clinical practice. The goal of this study was to use independent component analysis of high-density EEG to test whether we could relate electrocortical dynamics to lower limb muscle activation in a constrained motor task. A secondary goal was to assess the trial-by-trial consistency of the electrocortical dynamics by decoding the type of muscle action. Methods We recorded 264-channel EEG while 8 neurologically intact subjects performed isometric and isotonic, knee and ankle exercises at two different effort levels. Adaptive mixture independent component analysis (AMICA) parsed EEG into models of underlying source signals. We generated spectrograms for all electrocortical source signals and used a naïve Bayesian classifier to decode exercise type from trial-by-trial time-frequency data. Results AMICA captured different electrocortical source distributions for ankle and knee tasks. The fit of single-trial EEG to these models distinguished knee from ankle tasks with 80% accuracy. Electrocortical spectral modulations in the supplementary motor area were significantly different for isometric and isotonic tasks (p < 0.05). Isometric contractions elicited an event related desynchronization (ERD) in the α-band (8–12 Hz) and β-band (12–30 Hz) at joint torque onset and offset. Isotonic contractions elicited a sustained α- and β-band ERD throughout the trial. Classifiers based on supplementary motor area sources achieved a 4-way classification accuracy of 69% while classifiers based on electrocortical sources in multiple brain regions achieved a 4-way classification accuracy of 87%. Conclusions Independent component analysis of EEG reveals unique spatial and spectro-temporal electrocortical properties for different lower limb motor tasks. Using a broad distribution of electrocortical signals may improve classification of human lower limb movements from single-trial EEG.
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Affiliation(s)
- Joseph T Gwin
- Human Neuromechanics Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI, USA.
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Dieler AC, Tupak SV, Fallgatter AJ. Functional near-infrared spectroscopy for the assessment of speech related tasks. BRAIN AND LANGUAGE 2012; 121:90-109. [PMID: 21507475 DOI: 10.1016/j.bandl.2011.03.005] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Revised: 12/21/2010] [Accepted: 03/21/2011] [Indexed: 05/15/2023]
Abstract
Over the past years functional near-infrared spectroscopy (fNIRS) has substantially contributed to the understanding of language and its neural correlates. In contrast to other imaging techniques, fNIRS is well suited to study language function in healthy and psychiatric populations due to its cheap and easy application in a quiet and natural measurement setting. Its relative insensitivity for motion artifacts allows the use of overt speech tasks and the investigation of verbal conversation. The present review focuses on the numerous contributions of fNIRS to the field of language, its development, and related psychiatric disorders but also on its limitations and chances for the future.
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Affiliation(s)
- A C Dieler
- Department of Psychiatry, Psychosomatics, and Psychotherapy, University Wuerzburg, Germany
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Levy H, Ringuette D, Levi O. Rapid monitoring of cerebral ischemia dynamics using laser-based optical imaging of blood oxygenation and flow. BIOMEDICAL OPTICS EXPRESS 2012; 3:777-91. [PMID: 22574265 PMCID: PMC3345806 DOI: 10.1364/boe.3.000777] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2012] [Revised: 02/10/2012] [Accepted: 03/25/2012] [Indexed: 05/17/2023]
Abstract
Imaging blood flow or oxygenation changes using optical techniques is useful for monitoring cortical activity in healthy subjects as well as in diseased states such as stroke or epilepsy. However, in order to gain a better understanding of hemodynamics in conscious, freely moving animals, these techniques must be implemented in a small scale, portable design that is adaptable to a wearable format. We demonstrate a novel system which combines the two techniques of laser speckle contrast imaging and intrinsic optical signal imaging simultaneously, using compact laser sources, to monitor induced cortical ischemia in a full field format with high temporal acquisition rates. We further demonstrate the advantages of using combined measurements of speckle contrast and oxygenation to establish absolute flow velocities, as well as to statistically distinguish between veins and arteries. We accomplish this system using coherence reduction techniques applied to Vertical Cavity Surface Emitting Lasers (VCSELs) operating at 680, 795 and 850 nm. This system uses minimal optical components and can easily be adapted into a portable format for continuous monitoring of cortical hemodynamics.
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Affiliation(s)
- Hart Levy
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario, M5S 3G9,Canada
- The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
| | - Dene Ringuette
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario, M5S 3G9,Canada
| | - Ofer Levi
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario, M5S 3G9,Canada
- The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, M5S 3G4, Canada
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Caverzasi E, Pichiecchio A, Poloni GU, Calligaro A, Pasin M, Palesi F, Castellazzi G, Pasquini M, Biondi M, Barale F, Bastianello S. Magnetic resonance spectroscopy in the evaluation of treatment efficacy in unipolar major depressive disorder: a review of the literature. FUNCTIONAL NEUROLOGY 2012; 27:13-22. [PMID: 22687162 PMCID: PMC3812759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
More and more neuroimaging studies are using in vivo proton magnetic resonance spectroscopy (1H-MRS) to explore correlates of response to therapy in major depressive disorder (MDD). Their aim is to further understanding of the effects of neurotransmitter changes in areas involved in MDD and the mechanisms underlying a good treatment response. We set out to summarise the literature from the past fifteen years on biochemical correlates of treatment response in MDD patients, reflected in pre- and post-therapy changes in 1H-MRS measurements. Our literature search identified fifteen articles reporting 1H-MRS studies in MDD treatment; no study used 1P-MRS. Despite the wide diversity of 1H-MRS methods applied, brain regions studied, and metabolite changes found, there emerged strong evidence of a correlation between changes in neurometabolite concentrations, in particular glutamate, N-acetylaspartate and choline, and a good treatment response to pharmacotherapy or antidepressant stimulation techniques.
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Cherney LR, Patterson JP, Raymer AM. Intensity of Aphasia Therapy: Evidence and Efficacy. Curr Neurol Neurosci Rep 2011; 11:560-9. [DOI: 10.1007/s11910-011-0227-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Fractional anisotropy and mean diffusivity in the corpus callosum of patients with multiple sclerosis: the effect of physiotherapy. Neuroradiology 2011; 53:917-26. [PMID: 21556863 DOI: 10.1007/s00234-011-0879-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Accepted: 04/20/2011] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Modulation of neurodegeneration by physical activity is an active topic in contemporary research. The purpose of this study was to investigate changes in the brain's microstructure in multiple sclerosis (MS) after facilitation physiotherapy. METHODS Eleven patients with MS were examined using motor and neuropsychological testing and multimodal MRI at the beginning of the study, with second baseline measurement after 1 month without any therapy, and after a 2-month period of facilitation physiotherapy. Eleven healthy controls were examined at the beginning of the study and after 1 month. Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ (ax)), and radial diffusivity (λ (rad)) were calculated for the whole corpus callosum (CC) in the midsagittal slice of T1W 3D MPRAGE spatially normalized images. Data were analyzed using linear mixed-effect models, paired, and two-sample tests. RESULTS At the baseline, patients with MS showed significantly lower values in FA (p < 0.001), and significantly higher values in MD (p < 0.001), λ (ax) (p = 0.003), and λ (rad) (p < 0.001) compared to control subjects. The FA, MD, λ (ax), and λ (rad) did not change between the first and second baseline examinations in either group. Differences 2 months after initiating facilitation physiotherapy were in FA, MD, and in λ (rad) significantly higher than differences in healthy controls (p < 0.001 for FA, p = 0.02 for MD, and p = 0.002 for λ (rad)). In MS patients, FA in the CC significantly increased (p < 0.001), MD and λ (rad) significantly decreased (p = 0.014 and p = 0.002), and thus approached the values in healthy controls. CONCLUSION The results of the study show that facilitation physiotherapy influences brain microstructure measured by DTI.
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Meinzer M, Harnish S, Conway T, Crosson B. Recent developments in functional and structural imaging of aphasia recovery after stroke. APHASIOLOGY 2011; 25:271-290. [PMID: 21532927 PMCID: PMC3083028 DOI: 10.1080/02687038.2010.530672] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
BACKGROUND: Functional and structural neuroimaging techniques can increase our knowledge about the neural processes underlying recovery from post-stroke language impairments (aphasia). AIMS: In the present review we highlight recent developments in neuroimaging research of aphasia recovery. MAIN CONTRIBUTION: We review (a) cross-sectional findings in aphasia with regard to local brain functions and functional connectivity, (b) structural and functional imaging findings using longitudinal (intervention) paradigms, (c) new adjunct treatments that are guided by functional imaging techniques (e.g., electrical brain stimulation) and (d) studies related to the prognosis of language recovery and treatment responsiveness after stroke. CONCLUSIONS: More recent developments in data acquisition and analysis foster better understanding and more realistic modelling of the neural substrates of language recovery after stroke. Moreover, the combination of different neuroimaging protocols can provide converging evidence for neuroplastic brain remodelling during spontaneous and treatment-induced recovery. Researchers are also beginning to use sophisticated imaging analyses to improve accuracy of prognosis, which may eventually improve patient care by allowing for more efficient treatment planning. Brain stimulation techniques offer a new and exciting way to improve the recovery potential after stroke.
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Affiliation(s)
- Marcus Meinzer
- Department of Neurology, Center for Stroke Research Berlin & Cluster of Excellence NeuroCure, Charite, Universitätsmedizin Berlin, Berlin, Germany
- Department of Clinical & Health Psychology, University of Florida, Gainesville, FL, USA
| | - Stacy Harnish
- Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, FL, USA
- Department of Neurology, University of Florida, Gainesville, FL, USA
| | - Tim Conway
- Department of Clinical & Health Psychology, University of Florida, Gainesville, FL, USA
- Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, FL, USA
| | - Bruce Crosson
- Department of Clinical & Health Psychology, University of Florida, Gainesville, FL, USA
- Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, FL, USA
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Abstract
PURPOSE To determine if simple, robust spectacle mounted devices are feasible for the replacement of the mirror boxes currently used in the rehabilitation of patients suffering from phantom limb pain, complex regional pain syndrome and stroke. METHODS Four devices, using three different optical systems were produced: plane mirror, astronomical telescope using cylindrical lenses and two reflecting prism systems. RESULT The illusory effect of the devices was similar to that of the mirror box. CONCLUSIONS Any of the systems would be suitable to replace the mirror box, but the reflecting prism system is the easiest to set up.
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Spalice A, Nicita F, Papetti L, Ursitti F, Di Biasi C, Parisi P, Ruggieri M, Iannetti P. Usefulness of diffusion tensor imaging and fiber tractography in neurological and neurosurgical pediatric diseases. Childs Nerv Syst 2010; 26:995-1002. [PMID: 20552206 DOI: 10.1007/s00381-010-1192-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2010] [Accepted: 05/23/2010] [Indexed: 12/01/2022]
Abstract
INTRODUCTION Diffusion tensor imaging (DTI) with fiber tractography (FT) is a recently introduced imaging technique that is unique in providing detailed imaging of white matter (WM) tracts and connectivity between different regions of the brain not easily appreciated with other imaging methods. DISCUSSION DTI has been used in recent years to investigate several disease conditions involving WM, including brain malformations, cerebral ischemia, multiple sclerosis, neurocutaneous syndromes, and brain tumors. CONCLUSION In this paper, we focus our attention on the main applications of DTI-FT in the field of pediatric neurology, adding our personal experience.
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Affiliation(s)
- Alberto Spalice
- Department of Pediatrics, Child Neurology Division, Sapienza University of Rome, Viale Regina Elena 324, 00161 Rome, Italy
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Blood pressure treatment in acute ischemic stroke: a review of studies and recommendations. Curr Opin Neurol 2010; 23:46-52. [PMID: 20038827 DOI: 10.1097/wco.0b013e3283355694] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Elevated blood pressure (BP) is frequent in patients with acute ischemic stroke. Pathophysiological data support its usefulness to maintain adequate perfusion of the ischemic penumba. This review article aims to summarize the available evidence from clinical studies that examined the prognostic role of BP during the acute phase of ischemic stroke and intervention studies that assessed the efficacy of active BP alteration. RECENT FINDINGS We found 34 observational studies (33,470 patients), with results being inconsistent among the studies; most studies reported a negative association between increased levels of BP and clinical outcome, whereas a few studies showed clinical improvement with higher BP levels, clinical deterioration with decreased BP, or no association at all. Similarly, the conclusions drawn by the 18 intervention studies included in this review (1637 patients) were also heterogeneous. Very recent clinical data suggest a possible beneficial effect of early treatment with some antihypertensives on late clinical outcome. SUMMARY Observational and interventional studies of management of acute poststroke hypertension yield conflicting results. We discuss different explanations that may account for this and discuss the current guidelines and pathophysiological considerations for the management of acute poststroke hypertension.
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Crosson B, Ford A, McGregor KM, Meinzer M, Cheshkov S, Li X, Walker-Batson D, Briggs RW. Functional imaging and related techniques: an introduction for rehabilitation researchers. JOURNAL OF REHABILITATION RESEARCH AND DEVELOPMENT 2010; 47:vii-xxxiv. [PMID: 20593321 PMCID: PMC3225087 DOI: 10.1682/jrrd.2010.02.0017] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Functional neuroimaging and related neuroimaging techniques are becoming important tools for rehabilitation research. Functional neuroimaging techniques can be used to determine the effects of brain injury or disease on brain systems related to cognition and behavior and to determine how rehabilitation changes brain systems. These techniques include: functional magnetic resonance imaging (fMRI), positron emission tomography (PET), electroencephalography (EEG), magnetoencephalography (MEG), near infrared spectroscopy (NIRS), and transcranial magnetic stimulation (TMS). Related diffusion weighted magnetic resonance imaging techniques (DWI), including diffusion tensor imaging (DTI) and high angular resolution diffusion imaging (HARDI), can quantify white matter integrity. With the proliferation of these imaging techniques in rehabilitation research, it is critical that rehabilitation researchers, as well as consumers of rehabilitation research, become familiar with neuroimaging techniques, what they can offer, and their strengths and weaknesses The purpose to this review is to provide such an introduction to these neuroimaging techniques.
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Affiliation(s)
- Bruce Crosson
- VA RR&D Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, Florida
- Department of Clinical & Health Psychology, University of Florida, Gainesville, Florida
| | - Anastasia Ford
- Department of Psychology, University of Florida, Gainesville, Florida
| | - Keith M. McGregor
- VA RR&D Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Gainesville, Florida
- Department of Psychology, University of Florida, Gainesville, Florida
| | - Marcus Meinzer
- Department of Clinical & Health Psychology, University of Florida, Gainesville, Florida
| | - Sergey Cheshkov
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Xiufeng Li
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | | | - Richard W. Briggs
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
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Lakhan SE, Kirchgessner A, Hofer M. Inflammatory mechanisms in ischemic stroke: therapeutic approaches. J Transl Med 2009; 7:97. [PMID: 19919699 PMCID: PMC2780998 DOI: 10.1186/1479-5876-7-97] [Citation(s) in RCA: 792] [Impact Index Per Article: 52.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 11/17/2009] [Indexed: 01/01/2023] Open
Abstract
Acute ischemic stroke is the third leading cause of death in industrialized countries and the most frequent cause of permanent disability in adults worldwide. Despite advances in the understanding of the pathophysiology of cerebral ischemia, therapeutic options remain limited. Only recombinant tissue-plasminogen activator (rt-PA) for thrombolysis is currently approved for use in the treatment of this devastating disease. However, its use is limited by its short therapeutic window (three hours), complications derived essentially from the risk of hemorrhage, and the potential damage from reperfusion/ischemic injury. Two important pathophysiological mechanisms involved during ischemic stroke are oxidative stress and inflammation. Brain tissue is not well equipped with antioxidant defenses, so reactive oxygen species and other free radicals/oxidants, released by inflammatory cells, threaten tissue viability in the vicinity of the ischemic core. This review will discuss the molecular aspects of oxidative stress and inflammation in ischemic stroke and potential therapeutic strategies that target neuroinflammation and the innate immune system. Currently, little is known about endogenous counterregulatory immune mechanisms. However, recent studies showing that regulatory T cells are major cerebroprotective immunomodulators after stroke suggest that targeting the endogenous adaptive immune response may offer novel promising neuroprotectant therapies.
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Affiliation(s)
- Shaheen E Lakhan
- Global Neuroscience Initiative Foundation, Los Angeles, CA, USA.
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Rosendal F, Frandsen J, Chakravarty MM, Bjarkam CR, Pedersen M, Sangill R, Sørensen JC. New surgical technique reduces the susceptibility artefact at air-tissue interfaces on in vivo cerebral MRI in the Göttingen minipig. Brain Res Bull 2009; 80:403-7. [PMID: 19712728 DOI: 10.1016/j.brainresbull.2009.08.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2009] [Revised: 07/31/2009] [Accepted: 08/17/2009] [Indexed: 10/20/2022]
Abstract
Advanced and exclusive software solutions are offered to reduce susceptibility artefacts on MRI echo-planar sequences. We present a straightforward surgical technique to reduce the cortical distortion and signal loss that normally occur using diffusion tensor imaging (DTI) of the Göttingen minipig brain. Pronounced pneumatisation of the minipig cranium causes considerable susceptibility artefacts at the air/tissue interface around the frontal sinuses. Five Göttingen minipigs had burr holes drilled through the outer lamina of the skull bilaterally at the level of bregma. The underlying frontal sinuses were filled with a suspension of an MRI-compatible alginate. DTI was obtained before and after placing the medium in the sinus, quantifying the change using mutual information and Wilcoxon's rank-sum test. Fibertracking algorithms were applied to visualize the effect of treatment. We showed that the susceptibility artefacts were reduced at the air, bone and brain interfaces and that major cortical fiberbundles could be reliably visualized. This study demonstrated that DTI fibertracking of cortical bundles in experimental animals with extensive skull pneumatisation is feasible even when advanced software is unavailable.
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Affiliation(s)
- Frederikke Rosendal
- Center for Experimental Neuroscience (CENSE), Department of Neurosurgery, University Hospital of Aarhus, DK-8000 Aarhus C, Denmark.
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Braun C, Demarchi G, Papadelis C. Cortical Reorganization after Damage to the Central Nervous System. Neuroophthalmology 2009. [DOI: 10.1080/01658100902825521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Abstract
During the last decades, transcranial magnetic stimulation (TMS) has been used as a noninvasive method to investigate motor cortical reorganization and neuroplasticity in humans after stroke. An increasing number of studies in the field of motor control have used TMS to gain an understanding of the different aspects of stroke cortical physiology and motor recovery. This review addresses the effects of corticospinal tract (CST) lesions in humans and nonhuman primates on the functional organization of the motor system. We review information on the physiological mechanisms by which the CST contributes to normal motor control and to central nervous system reorganization following stroke when the CST is injured as measured using TMS. Insight into these physiological mechanisms has led to the development of scientifically sound interventional proposals in the field of neurorehabilitation.
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Affiliation(s)
- Monica A Perez
- Department of Physical Medicine and Rehabilitation, Center for the Neural Basis of Cognition, University of Pittsburgh, Pennsylvania, USA
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