1
|
Seusing N, Strauss S, Fleischmann R, Nafz C, Groppa S, Muthuraman M, Ding H, Byblow WD, Lotze M, Grothe M. The excitability of ipsilateral motor evoked potentials is not task-specific and spatially distinct from the contralateral motor hotspot. Exp Brain Res 2024; 242:1851-1859. [PMID: 38842754 PMCID: PMC11252234 DOI: 10.1007/s00221-024-06851-6] [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: 02/04/2023] [Accepted: 05/10/2024] [Indexed: 06/07/2024]
Abstract
OBJECTIVE The role of ipsilateral descending motor pathways in voluntary movement of humans is still a matter of debate, with partly contradictory results. The aim of our study therefore was to examine the excitability of ipsilateral motor evoked potentials (iMEPs) regarding site and the specificity for unilateral and bilateral elbow flexion extension tasks. METHODS MR-navigated transcranial magnetic stimulation mapping of the dominant hemisphere was performed in twenty healthy participants during tonic unilateral (iBB), bilateral homologous (bBB) or bilateral antagonistic elbow flexion-extension (iBB-cAE), the map center of gravity (CoG) and iMEP area from BB were obtained. RESULTS The map CoG of the ipsilateral BB was located more anterior-laterally than the hotspot of the contralateral BB within the primary motor cortex, with a significant difference in CoG in iBB and iBB-cAE, but not bBB compared to the hotspot for the contralateral BB (each p < 0.05). However, different tasks had no effect on the size of the iMEPs. CONCLUSION Our data demonstrated that excitability of ipsilateral and contralateral MEP differ spatially in a task-specific manner suggesting the involvement of different motor networks within the motor cortex.
Collapse
Affiliation(s)
- Nelly Seusing
- Department of Neurology, University Medicine of Greifswald, Greifswald, Germany
| | - Sebastian Strauss
- Department of Neurology, University Medicine of Greifswald, Greifswald, Germany
| | - Robert Fleischmann
- Department of Neurology, University Medicine of Greifswald, Greifswald, Germany
| | - Christina Nafz
- Department of Neurology, University Medicine of Greifswald, Greifswald, Germany
| | - Sergiu Groppa
- Imaging and Neurostimulation, Department of Neurology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Muthuraman Muthuraman
- Imaging and Neurostimulation, Department of Neurology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Neural Engineering with Signal Analytics and Artificial Intelligence (NESA-AI), Department of Neurology, University Medicine of Würzburg, Würzburg, Germany
| | - Hao Ding
- Imaging and Neurostimulation, Department of Neurology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
- Neural Engineering with Signal Analytics and Artificial Intelligence (NESA-AI), Department of Neurology, University Medicine of Würzburg, Würzburg, Germany
| | - Winston D Byblow
- Movement Neuroscience Laboratory, Department of Exercise Sciences, The University of Auckland, Auckland, New Zealand
- Centre for Brain Research, University of Auckland, Auckland, New Zealand
| | - Martin Lotze
- Functional Imaging Unit, Center for Diagnostic Radiology, University Medicine Greifswald, Greifswald, Germany
| | - Matthias Grothe
- Department of Neurology, University Medicine of Greifswald, Greifswald, Germany.
| |
Collapse
|
2
|
Chen Y, Jiang Y, Zhang Z, Li Z, Zhu C. Transcranial magnetic stimulation mapping of the motor cortex: comparison of five estimation algorithms. Front Neurosci 2023; 17:1301075. [PMID: 38130697 PMCID: PMC10733534 DOI: 10.3389/fnins.2023.1301075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 11/21/2023] [Indexed: 12/23/2023] Open
Abstract
Background There are currently five different kinds of transcranial magnetic stimulation (TMS) motor mapping algorithms available, from ordinary point-based algorithms to advanced field-based algorithms. However, there have been only a limited number of comparison studies conducted, and they have not yet examined all of the currently available algorithms. This deficiency impedes the judicious selection of algorithms for application in both clinical and basic neuroscience, and hinders the potential promotion of a potential superior algorithm. Considering the influence of algorithm complexity, further investigation is needed to examine the differences between fMRI peaks and TMS cortical hotspots that were identified previously. Methods Twelve healthy participants underwent TMS motor mapping and a finger-tapping task during fMRI. The motor cortex TMS mapping results were estimated by five algorithms, and fMRI activation results were obtained. For each algorithm, the prediction error was defined as the distance between the measured scalp hotspot and optimized coil position, which was determined by the maximum electric field strength in the estimated motor cortex. Additionally, the study identified the minimum number of stimuli required for stable mapping. Finally, the location difference between the TMS mapping cortical hotspot and the fMRI activation peak was analyzed. Results The projection yielded the lowest prediction error (5.27 ± 4.24 mm) among the point-based algorithms and the association algorithm yielded the lowest (6.66 ± 3.48 mm) among field-based estimation algorithms. The projection algorithm required fewer stimuli, possibly resulting from its suitability for the grid-based mapping data collection method. The TMS cortical hotspots from all algorithms consistently deviated from the fMRI activation peak (20.52 ± 8.46 mm for five algorithms). Conclusion The association algorithm might be a superior choice for clinical applications and basic neuroscience research, due to its lower prediction error and higher estimation sensitivity in the deep cortical structure, especially for the sulcus. It also has potential applicability in various other TMS domains, including language area mapping and more. Otherwise, our results provide further evidence that TMS motor mapping intrinsically differs from fMRI motor mapping.
Collapse
Affiliation(s)
- Yuanyuan Chen
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Yihan Jiang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
- Center for the Cognitive Science of Language, Beijing Language and Culture University, Beijing, China
| | - Zong Zhang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
| | - Zheng Li
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
- Center for Cognition and Neuroergonomics, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University Zhuhai, Zhuhai, China
| | - Chaozhe Zhu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China
- IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China
- Center for Collaboration and Innovation in Brain and Learning Sciences, Beijing Normal University, Beijing, China
| |
Collapse
|
3
|
Albishi AM. Why do different motor cortical areas activate the same muscles? Brain Struct Funct 2023; 228:2017-2024. [PMID: 37709903 DOI: 10.1007/s00429-023-02703-1] [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: 03/28/2023] [Accepted: 08/27/2023] [Indexed: 09/16/2023]
Abstract
The cortex contains multiple motor areas, including the primary motor cortex (M1) and supplementary motor area (SMA). Many muscles are represented in both the M1 and SMA, but the reason for this dual representation remains unclear. Previous work has shown that the M1 and SMA representations of a specific human muscle can be differentiated according to their functional connectivity with different brain areas located outside of the motor cortex. It is our perspective that this differential functional connectivity may be the neural substrate that allows an individual muscle to be accessed by distinct neural processes, such as those implementing volitional vs. postural task control. Here, we review existing human and animal literature suggesting how muscles are represented in the M1 and SMA and how these brain regions have distinct functions. We also discuss potential studies to further elucidate the distinct roles of the SMA and M1 in normal and dysfunctional motor control.
Collapse
Affiliation(s)
- Alaa M Albishi
- Department of Rehabilitation Sciences-Physical Therapy Division, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
| |
Collapse
|
4
|
Iannotti GR, Nadin I, Ivanova V, Tourdot Q, Lascano AM, Momjian S, Schaller KL, Lovblad KO, Grouiller F. Specificity of Quantitative Functional Brain Mapping with Arterial Spin-Labeling for Preoperative Assessment. AJNR Am J Neuroradiol 2023; 44:1302-1308. [PMID: 37857448 PMCID: PMC10631521 DOI: 10.3174/ajnr.a8006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/28/2023] [Indexed: 10/21/2023]
Abstract
BACKGROUND AND PURPOSE Arterial spin-labeling is a noninvasive MR imaging technique allowing direct and quantitative measurement of brain perfusion. Arterial spin-labeling is well-established in clinics for investigating the overall cerebral perfusion, but it is still occasionally employed during tasks. The typical contrast for functional MR imaging is blood oxygen level-dependent (BOLD) imaging, whose specificity could be biased in neurologic patients due to altered neurovascular coupling. This work aimed to validate the use of functional ASL as a noninvasive tool for presurgical functional brain mapping. This is achieved by comparing the spatial accuracy of functional ASL with transcranial magnetic stimulation as the criterion standard. MATERIALS AND METHODS Twenty-eight healthy participants executed a motor task and received a somatosensory stimulation, while BOLD imaging and arterial spin-labeling were acquired simultaneously. Transcranial magnetic stimulation was subsequently used to define hand somatotopy. RESULTS Functional ASL was found more adjacent to transcranial magnetic stimulation than BOLD imaging, with a significant shift along the inferior-to-superior direction. With respect to BOLD imaging, functional ASL was localized significantly more laterally, anteriorly, and inferiorly during motor tasks and pneumatic stimulation. CONCLUSIONS Our results confirm the specificity of functional ASL in targeting the regional neuronal excitability. Functional ASL could be considered as a valid supplementary technique to BOLD imaging for presurgical mapping when spatial accuracy is crucial for delineating eloquent cortex.
Collapse
Affiliation(s)
- Giannina R Iannotti
- From the Division of Neuroradiology, Diagnostic Department (G.R.I., K.O.L.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Isaure Nadin
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Vladimira Ivanova
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Quentin Tourdot
- Faculty of Pharmacy (Q.T.), University of Montpellier, Montpellier, France
| | - Agustina M Lascano
- Division of Neurology (A.M.L.), Department of Clinical Neuroscience, Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Shahan Momjian
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Karl L Schaller
- Department of Neurosurgery (G.R.I., I.N., V.I., S.M., K.L.S.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Karl O Lovblad
- From the Division of Neuroradiology, Diagnostic Department (G.R.I., K.O.L.), Geneva University Hospitals and University of Geneva, Geneva, Switzerland
| | - Frederic Grouiller
- Swiss Centre for Affective Sciences (F.G.), University of Geneva, Geneva, Switzerland
- Center for Biomedical Imaging (F.G.), MRI University of Geneva Cognitive and Affective Neuroimaging Section, Geneva, Switzerland
- Laboratory of Neurology and Imaging of Cognition (F.G.), Department of Basic Neurosciences, University of Geneva, Geneva, Switzerland
| |
Collapse
|
5
|
Kim H, Kim J, Lee G, Lee J, Kim YH. Task-Related Hemodynamic Changes Induced by High-Definition Transcranial Direct Current Stimulation in Chronic Stroke Patients: An Uncontrolled Pilot fNIRS Study. Brain Sci 2022; 12:453. [PMID: 35447985 PMCID: PMC9028267 DOI: 10.3390/brainsci12040453] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/22/2022] [Accepted: 03/23/2022] [Indexed: 02/01/2023] Open
Abstract
High-definition transcranial direct current stimulation (HD-tDCS) has recently been proposed as a tDCS approach that can be used on a specific cortical region without causing undesirable stimulation effects. In this uncontrolled pilot study, the cortical hemodynamic changes caused by HD-tDCS applied over the ipsilesional motor cortical area were investigated in 26 stroke patients. HD-tDCS using one anodal and four cathodal electrodes at 1 mA was administered for 20 min to C3 or C4 in four daily sessions. Cortical activation was measured as changes in oxyhemoglobin (oxyHb) concentration, as found using a functional near-infrared spectroscopy (fNIRS) system during the finger tapping task (FTT) with the affected hand before and after HD-tDCS. Motor-evoked potential and upper extremity functions were also measured before (T0) and after the intervention (T1). A group statistical parametric mapping analysis showed that the oxyHb concentration increased during the FTT in both the affected and unaffected hemispheres before HD-tDCS. After HD-tDCS, the oxyHb concentration increased only in the affected hemisphere. In a time series analysis, the mean and integral oxyHb concentration during the FTT showed a noticeable decrease in the channel closest to the hand motor hotspot (hMHS) in the affected hemisphere after HD-tDCS compared with before HD-tDCS, in accordance with an improvement in the function of the affected upper extremity. These results suggest that HD-tDCS might be helpful to rebalance interhemispheric cortical activity and to reduce the hemodynamic burden on the affected hemisphere during hand motor tasks. Noticeable changes in the area adjacent to the affected hMHS may imply that personalized HD-tDCS electrode placement is needed to match each patient's individual hMHS location.
Collapse
Affiliation(s)
- Heegoo Kim
- Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea; (H.K.); (J.K.); (G.L.)
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06355, Korea
| | - Jinuk Kim
- Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea; (H.K.); (J.K.); (G.L.)
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06355, Korea
| | - Gihyoun Lee
- Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea; (H.K.); (J.K.); (G.L.)
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06355, Korea
| | - Jungsoo Lee
- Department of Medical IT Convergence Engineering, Kumoh National Institute of Technology, Gumi 39253, Korea
| | - Yun-Hee Kim
- Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea; (H.K.); (J.K.); (G.L.)
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06355, Korea
- Department of Medical Device Management & Research, Department of Digital Health, SAIHST, Sungkyunkwan University, Seoul 06355, Korea
| |
Collapse
|
6
|
Davies JL. Using transcranial magnetic stimulation to map the cortical representation of lower-limb muscles. Clin Neurophysiol Pract 2020; 5:87-99. [PMID: 32455179 PMCID: PMC7235616 DOI: 10.1016/j.cnp.2020.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/30/2020] [Accepted: 04/18/2020] [Indexed: 01/25/2023] Open
Abstract
Objective To evaluate the extent to which transcranial magnetic stimulation (TMS) can identify discrete cortical representation of lower-limb muscles in healthy individuals. Methods Motor evoked potentials were recorded from resting vastus medialis, rectus femoris, vastus lateralis, medial and lateral hamstring, and medial and lateral gastrocnemius muscles on the right leg of 16 young healthy adults using bipolar surface electrodes. TMS was delivered through a 110-mm double-cone coil at 63 sites over the left hemisphere. Location and size of cortical representation and number of discrete peaks were quantified. Results Within the quadriceps group there was a main effect of muscle on anterior-posterior centre of gravity (p = 0.010), but the magnitude of the difference was small. There was also a main effect of muscle on medial-lateral hotspot (p = 0.027) and map volume (p = 0.047), but no post-hoc tests were significant. The topography of each lower-limb muscle was complex and variable across individuals. Conclusions TMS delivered with a 110-mm double-cone coil could not reliably identify discrete cortical representations of resting lower-limb muscles when responses were measured using bipolar surface electromyography. Significance The characteristics of the cortical representation provide a basis against which to evaluate cortical reorganisation in clinical populations.
Collapse
Affiliation(s)
- Jennifer L Davies
- School of Healthcare Sciences, Cardiff University, United Kingdom.,Biomechanics and Bioengineering Research Centre Versus Arthritis, Cardiff University, United Kingdom.,Cardiff University Brain Research Imaging Centre, Cardiff University, United Kingdom
| |
Collapse
|
7
|
Nakagawa K, Takemi M, Nakanishi T, Sasaki A, Nakazawa K. Cortical reorganization of lower-limb motor representations in an elite archery athlete with congenital amputation of both arms. NEUROIMAGE-CLINICAL 2019; 25:102144. [PMID: 31958685 PMCID: PMC6970184 DOI: 10.1016/j.nicl.2019.102144] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 12/13/2019] [Accepted: 12/21/2019] [Indexed: 02/07/2023]
Abstract
We investigated cortical reorganization in an amputated archer who used his feet. Lower-limb motor representations were examined using fMRI and TMS mapping. M1 areas innervating lower-limb muscles were larger in the amputated athlete. The toe and knee representations were expanded towards the lateral part of the M1. Paralympic athletes have a unique and dynamic M1 plasticity.
Despite their disabilities, top Paralympic athletes have better motor skills than able-bodied athletes. However, the neural underpinnings of these better motor skills remain unclear. We investigated the reorganization of the primary motor cortex (M1) in a Paralympic athlete with congenital amputation of both arms who holds the world record for the farthest accurate shot in archery (Amputee Archer: AA). We recorded brain activity during contraction of right toe, ankle, knee, and hip joint muscles in the AA and 12 able-bodied control subjects using functional magnetic resonance imaging. The results revealed that M1 activation was more widespread in the AA compared with control subjects during all tasks, and shifted towards the lateral part of the M1 during contraction of toe and knee muscles. We also conducted a motor mapping experiment using navigated transcranial magnetic stimulation. The M1 area receiving stimulation elicited motor-evoked potentials from the toe, lower-leg, and thigh muscles, which were larger in the AA compared with 12 control subjects. Furthermore, the AA's motor maps were shifted towards the lateral side of M1. These results suggest an expansion of lower-limb M1 representation towards the lateral side of M1, including the trunk and upper-limb representations, and an expansion of the area of corticomotor neurons innervating the lower limb muscles in the AA. This unique M1 reorganization could underpin the AA's excellent archery performance in the absence of upper limbs. The current results suggest that Paralympic athletes may exhibit extreme M1 plasticity, which could arise through a combination of rigorous long-term motor training and compensatory M1 reorganization for missing body parts.
Collapse
Affiliation(s)
- Kento Nakagawa
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan; The Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan; Faculty of Sport Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama, 359-1192, Japan
| | - Mitsuaki Takemi
- Division of Physical and Health Education, Graduate School of Education, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan; Japan Science and Technology Agency, PRESTO, 4-1-8 Honmachi, Kawaguchi, Saitama, 332-0012, Japan
| | - Tomoya Nakanishi
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan; The Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan
| | - Atsushi Sasaki
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan; The Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan
| | - Kimitaka Nakazawa
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
| |
Collapse
|
8
|
Wang J, Meng HJ, Ji GJ, Jing Y, Wang HX, Deng XP, Feng ZJ, Zhao N, Zang YF, Zhang J. Finger Tapping Task Activation vs. TMS Hotspot: Different Locations and Networks. Brain Topogr 2019; 33:123-134. [PMID: 31691912 PMCID: PMC6943404 DOI: 10.1007/s10548-019-00741-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 10/22/2019] [Indexed: 12/15/2022]
Abstract
Both functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) have been used to non-invasively localize the human motor functional area. These locations can be clinically used as stimulation target of TMS treatment. However, it has been reported that the finger tapping fMRI activation and TMS hotspot were not well-overlapped. The aim of the current study was to measure the distance between the finger tapping fMRI activation and the TMS hotspot, and more importantly, to compare the network difference by using resting-state fMRI. Thirty healthy participants underwent resting-state fMRI, task fMRI, and then TMS hotspot localization. We found significant difference of locations between finger tapping fMRI activation and TMS hotspot. Specifically, the finger tapping fMRI activation was more lateral than the TMS hotspot in the premotor area. The fMRI activation peak and TMS hotspot were taken as seeds for resting-state functional connectivity analyses. Compared with TMS hotspot, finger tapping fMRI activation peak showed more intensive functional connectivity with, e.g., the bilateral premotor, insula, putamen, and right globus pallidus. The findings more intensive networks of finger tapping activation than TMS hotspot suggest that TMS treatment targeting on the fMRI activation area might result in more remote effects and would be more helpful for TMS treatment on movement disorders.
Collapse
Affiliation(s)
- Jue Wang
- School of Psychology, Shanghai University of Sport, Shanghai, 200438, China
| | - Hai-Jiang Meng
- School of Psychology, Shanghai University of Sport, Shanghai, 200438, China
| | - Gong-Jun Ji
- Department of Medical Psychology, Chaohu Clinical Medical College, Anhui Medical University, Hefei, 230032, China.,Collaborative Innovation Centre of Neuropsychiatric Disorder and Mental Health, Hefei, 230032, Anhui, China
| | - Ying Jing
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Hong-Xiao Wang
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Xin-Ping Deng
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Zi-Jian Feng
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Na Zhao
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China.,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China.,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China
| | - Yu-Feng Zang
- Institutes of Psychological Sciences, Hangzhou Normal University, Hangzhou, 311121, China. .,Zhejiang Key Laboratory for Research in Assessment of Cognitive Impairments, Hangzhou, 311121, China. .,Center for Cognition and Brain Disorders and the Affiliated Hospital, Hangzhou Normal University, Hangzhou, 310015, China.
| | - Jian Zhang
- School of Psychology, Shanghai University of Sport, Shanghai, 200438, China.
| |
Collapse
|
9
|
Hamidian S, Vachha B, Jenabi M, Karimi S, Young RJ, Holodny AI, Peck KK. Resting-State Functional Magnetic Resonance Imaging and Probabilistic Diffusion Tensor Imaging Demonstrate That the Greatest Functional and Structural Connectivity in the Hand Motor Homunculus Occurs in the Area of the Thumb. Brain Connect 2019; 8:371-379. [PMID: 29987948 DOI: 10.1089/brain.2018.0589] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The primary hand motor region is classically believed to be in the "hand knob" area in the precentral gyrus (PCG). However, hand motor task-based activation is often localized outside this area. The purpose of this study is to investigate the structural and functional connectivity driven by different seed locations corresponding to the little, index, and thumb in the PCG using probabilistic diffusion tractography (PDT) and resting-state functional magnetic resonance imaging (rfMRI). Twelve healthy subjects had three regions of interest (ROIs) placed in the left PCG: lateral to the hand knob (thumb area), within the hand knob (index finger area), and medial to the hand knob (little finger area). Connectivity maps were generated using PDT and rfMRI. Individual and group level analyses were performed. Results show that the greatest hand motor connectivity between both hemispheres was obtained using the ROI positioned just lateral to the hand knob in the PCG (the thumb area). The number of connected voxels in the PCG between the two hemispheres was greatest in the lateral-most ROI (the thumb area): 279 compared with 13 for the medial-most ROI and 9 for the central hand knob ROI. Similarly, the highest white matter connectivity between the two hemispheres resulted from the ROI placed in the lateral portion of PCG (p < 0.003). The maximal functional and structural connectivity of the hand motor area between hemispheres occurs in the thumb area, located laterally at the "hand knob." Thus, this location appears maximal for rfMRI and PDT seeding of the motor area.
Collapse
Affiliation(s)
- Shaminta Hamidian
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Behroze Vachha
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Mehrnaz Jenabi
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Sasan Karimi
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Robert J Young
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Andrei I Holodny
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York
| | - Kyung K Peck
- 1 Department of Radiology, Memorial Sloan-Kettering Cancer Center , New York, New York.,2 Department of Medical Physics, Memorial Sloan-Kettering Cancer Center , New York, New York
| |
Collapse
|
10
|
Pitkänen M, Yazawa S, Airaksinen K, Lioumis P, Nurminen J, Pekkonen E, Mäkelä JP. Localization of Sensorimotor Cortex Using Navigated Transcranial Magnetic Stimulation and Magnetoencephalography. Brain Topogr 2019; 32:873-881. [PMID: 31093863 PMCID: PMC6707977 DOI: 10.1007/s10548-019-00716-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 05/06/2019] [Indexed: 12/17/2022]
Abstract
The mapping of the sensorimotor cortex gives information about the cortical motor and sensory functions. Typical mapping methods are navigated transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG). The differences between these mapping methods are, however, not fully known. TMS center of gravities (CoGs), MEG somatosensory evoked fields (SEFs), corticomuscular coherence (CMC), and corticokinematic coherence (CKC) were mapped in ten healthy adults. TMS mapping was performed for first dorsal interosseous (FDI) and extensor carpi radialis (ECR) muscles. SEFs were induced by tactile stimulation of the index finger. CMC and CKC were determined as the coherence between MEG signals and the electromyography or accelerometer signals, respectively, during voluntary muscle activity. CMC was mapped during the activation of FDI and ECR muscles separately, whereas CKC was measured during the waving of the index finger at a rate of 3–4 Hz. The maximum CMC was found at beta frequency range, whereas maximum CKC was found at the movement frequency. The mean Euclidean distances between different localizations were within 20 mm. The smallest distance was found between TMS FDI and TMS ECR CoGs and longest between CMC FDI and CMC ECR sites. TMS-inferred localizations (CoGs) were less variable across participants than MEG-inferred localizations (CMC, CKC). On average, SEF locations were 8 mm lateral to the TMS CoGs (p < 0.01). No differences between hemispheres were found. Based on the results, TMS appears to be more viable than MEG in locating motor cortical areas.
Collapse
Affiliation(s)
- Minna Pitkänen
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland. .,Department of Clinical Neurophysiology, Kuopio University Hospital, Kuopio, Finland. .,A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, P. O. Box 1627, 70211, Kuopio, Finland.
| | - Shogo Yazawa
- Department of Systems Neuroscience, Sapporo Medical University, Sapporo, Japan
| | - Katja Airaksinen
- BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.,Department of Neurology, Helsinki University Hospital, Helsinki, Finland.,Department of Clinical Neurosciences (Neurology), University of Helsinki, Helsinki, Finland
| | - Pantelis Lioumis
- Department of Neuroscience and Biomedical Engineering, Aalto University School of Science, Espoo, Finland.,BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Jussi Nurminen
- BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Eero Pekkonen
- Department of Neurology, Helsinki University Hospital, Helsinki, Finland.,Department of Clinical Neurosciences (Neurology), University of Helsinki, Helsinki, Finland
| | - Jyrki P Mäkelä
- BioMag Laboratory, HUS Medical Imaging Center, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| |
Collapse
|
11
|
Meincke J, Hewitt M, Reischl M, Rupp R, Schmidt-Samoa C, Liebetanz D. Cortical representation of auricular muscles in humans: A robot-controlled TMS mapping and fMRI study. PLoS One 2018; 13:e0201277. [PMID: 30052653 PMCID: PMC6065161 DOI: 10.1371/journal.pone.0201277] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 07/12/2018] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Most humans have the ability to activate the auricular muscles. Although (intentional) control suggests an involvement of higher cortical centers underlying posterior auricular muscle (PAM) activation, the cortical representation of the auricular muscles is still unknown. METHODS With the purpose of identifying a possible cortical representation area we performed automated robotic and image-guided transcranial magnetic stimulation (TMS) mapping (n = 8) and functional magnetic resonance imaging (fMRI) (n = 13). For topographical comparison, a similar experimental protocol was applied for the first dorsal interosseus muscle (FDI) of the hand. RESULTS The calculated centers of gravity (COGs) of both muscles were located on the precentral gyrus with the PAM COGs located more laterally compared to the FDI. The distance between the mean PAM and mean FDI COG was 26.3 mm. The TMS mapping results were confirmed by fMRI, which showed a dominance of cortical activation within the precentral gyrus during the corresponding motor tasks. The correspondence of TMS and fMRI results was high. CONCLUSION The involvement of the primary motor cortex in PAM activation might point to an evolved function of the auricular muscles in humans and/or the ability of intentional (and selective) muscle activation.
Collapse
Affiliation(s)
- Jonna Meincke
- Clinic of Clinical Neurophysiology, Georg August University of Göttingen,
University Medical Center, Göttingen, Germany
| | - Manuel Hewitt
- Clinic of Clinical Neurophysiology, Georg August University of Göttingen,
University Medical Center, Göttingen, Germany
| | - Markus Reischl
- Institute for Applied Computer Science, Karlsruhe Institute of
Technology, Eggenstein-Leopoldshafen, Germany
| | - Rüdiger Rupp
- Spinal Cord Injury Center, Heidelberg University Hospital, Heidelberg,
Germany
| | - Carsten Schmidt-Samoa
- Department of Cognitive Neurology, Georg August University of Göttingen,
University Medical Center, Göttingen, Germany
| | - David Liebetanz
- Clinic of Clinical Neurophysiology, Georg August University of Göttingen,
University Medical Center, Göttingen, Germany
| |
Collapse
|
12
|
Novikov PA, Nazarova MA, Nikulin VV. TMSmap - Software for Quantitative Analysis of TMS Mapping Results. Front Hum Neurosci 2018; 12:239. [PMID: 30038562 PMCID: PMC6046372 DOI: 10.3389/fnhum.2018.00239] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 05/24/2018] [Indexed: 12/13/2022] Open
Abstract
The use of the MRI-navigation system ensures accurate targeting of TMS. This, in turn, results in TMS motor mapping becoming a routinely used procedure in neuroscience and neurosurgery. However, currently, there is no standardized methodology for assessment of TMS motor-mapping results. Therefore, we developed TMSmap—free standalone graphical interface software for the quantitative analysis of the TMS motor mapping results (http://tmsmap.ru/). In addition to the estimation of standard parameters (such as the size of cortical muscle representation and the center of gravity location), it allows estimation of the volume of cortical representations, excitability profile of the cortical surface map, and the overlap between cortical representations. The input data for the software includes the coordinates of the coil position (or electric field maximum) and the corresponding response in each stimulation point. TMSmap has been developed for versatile assessment and comparison of TMS maps relating to different experimental interventions including, but not limited to longitudinal, pharmacological and clinical studies (e.g., stroke recovery). To illustrate the use of TMSmap we provide examples of the actual TMS motor-mapping analysis of two healthy subjects and one chronic stroke patient.
Collapse
Affiliation(s)
- Pavel A Novikov
- Centre for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia
| | - Maria A Nazarova
- Centre for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia
| | - Vadim V Nikulin
- Centre for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of Economics, Moscow, Russia.,Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.,Neurophysics Group, Department of Neurology, Campus Benjamin Franklin, Charité-Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
13
|
Neva JL, Gallina A, Peters S, Garland SJ, Boyd LA. Differentiation of motor evoked potentials elicited from multiple forearm muscles: An investigation with high-density surface electromyography. Brain Res 2017; 1676:91-99. [PMID: 28935187 DOI: 10.1016/j.brainres.2017.09.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 09/07/2017] [Accepted: 09/13/2017] [Indexed: 11/25/2022]
Abstract
Transcranial magnetic stimulation (TMS) is a non-invasive method to measure corticospinal excitability of the primary motor cortex. However, motor evoked potentials (MEPs) elicited by TMS in a target muscle are variable; inconsistent MEPs may be due to overlapping cortical muscle representations and/or volume conduction from neighbouring muscles. The source of variable muscle responses may not be apparent using conventional bipolar electromyography (EMG), particularly over areas with several distinct neighbouring muscles (e.g. the forearm). High-density surface EMG (HDsEMG) may provide a useful means to investigate the underlying variability in amplitude and spatial distribution of MEPs. Here, we investigated the spatial distribution of MEPs in the forearm extensors using HDsEMG. HDsEMG consisted of a 16×5 grid of surface electrodes placed on the right (dominant) dorsal forearm over the extensor carpi radialis (ECR), ulnaris (ECU) and extensor digitorum communis finger extensors (EDC). MEP amplitude and distribution were recorded from 100 to 170% of resting (RMT) and active motor threshold (AMT). The distribution of MEPs was correlated to the activity recorded during selective, isometric contractions of the ECR, ECU, middle (EDC-D3) and ring (EDC-D4) finger extensors to determine the spatial distribution of MEPs in the forearm extensors. Although ECR was the hotspot, resting MEP spatial distribution was primarily correlated to that of EDC-D4 and ECU. With background ECR activation, the spatial distribution of MEPs correlated strongly with ECR. Further, while holding a background ECR contraction, EDC-D4 and ECU MEPs increased with greater stimulation intensity. Our results suggest that HDsEMG provides a useful way to differentiate which wrist extensor muscles are activated by TMS.
Collapse
Affiliation(s)
- J L Neva
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
| | - A Gallina
- Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - S Peters
- Graduate Program in Rehabilitation Sciences, Faculty of Medicine, University of British Columbia, Vancouver, Canada
| | - S J Garland
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada; Faculty of Health Sciences, University of Western Ontario, London, Ontario, Canada N6A 5B9
| | - L A Boyd
- Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
14
|
Fricke C, Gentner R, Rumpf JJ, Weise D, Saur D, Classen J. Differential spatial representation of precision and power grasps in the human motor system. Neuroimage 2017; 158:58-69. [DOI: 10.1016/j.neuroimage.2017.06.080] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 10/19/2022] Open
|
15
|
Smith JA, Albishi A, Babikian S, Asavasopon S, Fisher BE, Kutch JJ. The motor cortical representation of a muscle is not homogeneous in brain connectivity. Exp Brain Res 2017. [PMID: 28631147 DOI: 10.1007/s00221-017-5011-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Functional connectivity patterns of the motor cortical representational area of single muscles have not been extensively mapped in humans, particularly for the axial musculature. Functional connectivity may provide a neural substrate for adaptation of muscle activity in axial muscles that have both voluntary and postural functions. The purpose of this study was to combine brain stimulation and neuroimaging to both map the cortical representation of the external oblique (EO) in primary motor cortex (M1) and supplementary motor area (SMA), and to establish the resting-state functional connectivity associated with this representation. Motor-evoked potentials were elicited from the EO muscle in stimulation locations encompassing M1 and SMA. The coordinates of locations with the largest motor-evoked potentials were confirmed with task-based fMRI imaging during EO activation. The M1 and SMA components of the EO representation demonstrated significantly different resting-state functional connectivity with other brain regions: the SMA representation of the EO muscle was significantly more connected to the putamen and cerebellum, and the M1 representation of the EO muscle was significantly more connected to somatosensory cortex and the superior parietal lobule. This study confirms the representation of a human axial muscle in M1 and SMA, and demonstrates for the first time that different parts of the cortical representation of a human axial muscle have resting-state functional connectivity with distinct brain regions. Future studies can use the brain regions of interest we have identified here to test the association between resting-state functional connectivity and control of the axial muscles.
Collapse
Affiliation(s)
- Jo Armour Smith
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
- Department of Physical Therapy, Chapman University, Irvine, CA, USA
| | - Alaa Albishi
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
- Department of Rehabilitation Sciences-Physical Therapy Division, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Sarine Babikian
- Department of Mechanical Engineering, University of Southern California, Los Angeles, CA, USA
| | - Skulpan Asavasopon
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
- Department of Physical Therapy, Loma Linda University, Loma Linda, CA, USA
| | - Beth E Fisher
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA
- Department of Neurology, University of Southern California, Los Angeles, CA, USA
| | - Jason J Kutch
- Division of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA.
| |
Collapse
|
16
|
Sankarasubramanian V, Machado AG, Conforto AB, Potter-Baker KA, Cunningham DA, Varnerin NM, Wang X, Sakaie K, Plow EB. Inhibition versus facilitation of contralesional motor cortices in stroke: Deriving a model to tailor brain stimulation. Clin Neurophysiol 2017; 128:892-902. [PMID: 28402865 DOI: 10.1016/j.clinph.2017.03.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 03/08/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The standard approach to brain stimulation in stroke is based on the premise that ipsilesional M1 (iM1) is important for motor function of the paretic upper limb, while contralesional cortices compete with iM1. Therefore, the approach typically advocates facilitating iM1 and/or inhibiting contralesional M1 (cM1). But, this approach fails to elicit much improvement in severely affected patients, who on account of extensive damage to ipsilesional pathways, cannot rely on iM1. These patients are believed to instead rely on the undamaged cortices, especially the contralesional dorsal premotor cortex (cPMd), for support of function of the paretic limb. Here, we tested for the first time whether facilitation of cPMd could improve paretic limb function in severely affected patients, and if a cut-off could be identified to separate responders to cPMd from responders to the standard approach to stimulation. METHODS In a randomized, sham-controlled crossover study, fifteen patients received the standard approach of stimulation involving inhibition of cM1 and a new approach involving facilitation of cPMd using repetitive transcranial magnetic stimulation (rTMS). Patients also received rTMS to control areas. At baseline, impairment [Upper Extremity Fugl-Meyer (UEFMPROXIMAL, max=36)] and damage to pathways [fractional anisotropy (FA)] was measured. We measured changes in time to perform proximal paretic limb reaching, and neurophysiology using TMS. RESULTS Facilitation of cPMd generated more improvement in severely affected patients, who had experienced greater damage and impairment than a cut-off value of FA (0.5) and UEFMPROXIMAL (26-28). The standard approach instead generated more improvement in mildly affected patients. Responders to cPMd showed alleviation of interhemispheric competition imposed on iM1, while responders to the standard approach showed gains in ipsilesional excitability in association with improvement. CONCLUSIONS A preliminary cut-off level of severity separated responders for standard approach vs. facilitation of cPMd. SIGNIFICANCE Cut-offs identified here could help select candidates for tailored stimulation in future studies so patients in all ranges of severity could potentially achieve maximum benefit in function of the paretic upper limb.
Collapse
Affiliation(s)
| | - Andre G Machado
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Adriana B Conforto
- Neurology Clinical Division, Neurology Department, Hospital das Clinicas, São Paulo University, 05508-090 São Paulo, SP, Brazil; Hospital Israelita Albert Einstein, 05652-900 São Paulo, SP, Brazil
| | - Kelsey A Potter-Baker
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - David A Cunningham
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - Nicole M Varnerin
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Xiaofeng Wang
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Ken Sakaie
- Department of Diagnostic Radiology, Imaging Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Ela B Plow
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA; Department of Physical Medicine and Rehabilitation, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA.
| |
Collapse
|
17
|
Elliott JM, Owen M, Bishop MD, Sparks C, Tsao H, Walton DM, Weber KA, Wideman TH. Measuring Pain for Patients Seeking Physical Therapy: Can Functional Magnetic Resonance Imaging (fMRI) Help? Phys Ther 2017; 97:145-155. [PMID: 27470977 DOI: 10.2522/ptj.20160089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/19/2016] [Indexed: 11/17/2022]
Abstract
In the multidisciplinary fields of pain medicine and rehabilitation, advancing techniques such as functional magnetic resonance imaging (fMRI) are used to enhance our understanding of the pain experience. Given that such measures, in some circles, are expected to help us understand the brain in pain, future research in pain measurement is undeniably rich with possibility. However, pain remains intensely personal and represents a multifaceted experience, unique to each individual; no single measure in isolation, fMRI included, can prove or quantify its magnitude beyond the patient self-report. Physical therapists should be aware of cutting-edge advances in measuring the patient's pain experience, and they should work closely with professionals in other disciplines (eg, magnetic resonance physicists, biomedical engineers, radiologists, psychologists) to guide the exploration and development of multimodal pain measurement and management on a patient-by-patient basis. The primary purpose of this perspective article is to provide a brief overview of fMRI and inform physical therapist clinicians of the pros and cons when utilized as a measure of the patient's perception of pain. A secondary purpose is to describe current known factors that influence the quality of fMRI data and its analyses, as well as the potential for future clinical applications relevant to physical therapist practice. Lastly, the interested reader is introduced and referred to existing guidelines and recommendations for reporting fMRI research.
Collapse
|
18
|
MRI Biomarkers for Hand-Motor Outcome Prediction and Therapy Monitoring following Stroke. Neural Plast 2016; 2016:9265621. [PMID: 27747108 PMCID: PMC5056270 DOI: 10.1155/2016/9265621] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/23/2016] [Indexed: 01/01/2023] Open
Abstract
Several biomarkers have been identified which enable a considerable prediction of hand-motor outcome after cerebral damage already in the subacute stage after stroke. We here review the value of MRI biomarkers in the evaluation of corticospinal integrity and functional recruitment of motor resources. Many of the functional imaging parameters are not feasible early after stroke or for patients with high impairment and low compliance. Whereas functional connectivity parameters have demonstrated varying results on their predictive value for hand-motor outcome, corticospinal integrity evaluation using structural imaging showed robust and high predictive power for patients with different levels of impairment. Although this is indicative of an overall higher value of structural imaging for prediction, we suggest that this variation be explained by structure and function relationships. To gain more insight into the recovering brain, not only one biomarker is needed. We rather argue for a combination of different measures in an algorithm to classify fine-graded subgroups of patients. Approaches to determining biomarkers have to take into account the established markers to provide further information on certain subgroups. Assessing the best therapy approaches for individual patients will become more feasible as these subgroups become specified in more detail. This procedure will help to considerably save resources and optimize neurorehabilitative therapy.
Collapse
|
19
|
Ahdab R, Ayache SS, Brugières P, Farhat WH, Lefaucheur JP. The Hand Motor Hotspot is not Always Located in the Hand Knob: A Neuronavigated Transcranial Magnetic Stimulation Study. Brain Topogr 2016; 29:590-7. [PMID: 26980192 DOI: 10.1007/s10548-016-0486-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 03/10/2016] [Indexed: 10/22/2022]
Abstract
The hand motor hot spot (hMHS) is one of the most salient parameters in transcranial magnetic stimulation (TMS) practice, notably used for targeting. It is commonly accepted that the hMHS corresponds to the hand representation within the primary motor cortex (M1). Anatomical and imaging studies locate this representation in a region of the central sulcus called the "hand knob". The aim of this study was to determine if the hMHS location corresponds to its expected location at the hand knob. Twelve healthy volunteers and eleven patients with chronic neuropathic pain of various origins, but not related to a brain lesion, were enrolled. Morphological magnetic resonance imaging of the brain was normal in all participants. Both hemispheres were studied in all participants except four (two patients and two healthy subjects). Cortical mapping of the hand motor area was conducted using a TMS-dedicated navigation system and recording motor evoked potentials (MEPs) in the contralateral first dorsal interosseous (FDI) muscle. We then determined the anatomical position of the hMHS, defined as the stimulation site providing the largest FDI-MEPs. In 45 % of hemispheres of normal subjects and 25 % of hemispheres of pain patients, the hMHS was located over the central sulcus, most frequently at the level of the hand knob. However, in the other cases, the hMHS was located outside M1, most frequently anteriorly over the precentral or middle frontal gyrus. This study shows that the hMHS does not always correspond to the hand knob and M1 location in healthy subjects or patients. Therefore, image-guided navigation is needed to improve the anatomical accuracy of TMS targeting, even for M1.
Collapse
Affiliation(s)
- Rechdi Ahdab
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France.,Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, 51 avenue de Lattre de Tassigny, 94010, Créteil, France.,Neurology Division, University Medical Center Rizk Hospital, Beirut, Lebanon
| | - Samar S Ayache
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France. .,Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, 51 avenue de Lattre de Tassigny, 94010, Créteil, France. .,Neurology Division, University Medical Center Rizk Hospital, Beirut, Lebanon.
| | - Pierre Brugières
- Service de Neuroradiologie, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, Créteil, France
| | - Wassim H Farhat
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France.,Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, 51 avenue de Lattre de Tassigny, 94010, Créteil, France
| | - Jean-Pascal Lefaucheur
- EA 4391, Excitabilité Nerveuse et Thérapeutique, Université Paris-Est-Créteil, Créteil, France.,Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, Assistance Publique - Hôpitaux de Paris, 51 avenue de Lattre de Tassigny, 94010, Créteil, France
| |
Collapse
|
20
|
Meincke J, Hewitt M, Batsikadze G, Liebetanz D. Automated TMS hotspot-hunting using a closed loop threshold-based algorithm. Neuroimage 2016; 124:509-517. [DOI: 10.1016/j.neuroimage.2015.09.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 08/28/2015] [Accepted: 09/07/2015] [Indexed: 01/30/2023] Open
|
21
|
Magalhães SC, Kaelin-Lang A, Sterr A, do Prado GF, Eckeli AL, Conforto AB. Transcranial magnetic stimulation for evaluation of motor cortical excitability in restless legs syndrome/Willis-Ekbom disease. Sleep Med 2015; 16:1265-73. [PMID: 26429756 DOI: 10.1016/j.sleep.2015.03.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Revised: 02/27/2015] [Accepted: 03/29/2015] [Indexed: 11/30/2022]
Abstract
There is no consensus about mechanisms underlying restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED). Cortical excitability may be abnormal in RLS. Transcranial magnetic stimulation (TMS) can provide insight about cortical excitability. We reviewed studies about measures of excitability to TMS in RLS. Original studies published between January 1999 and January 2015 were searched in PubMed, Scopus, and Web of Science databases. Inclusion criteria were as follows: original studies involving primary RLS in patients from both sexes and ages between 18 and 85 years; TMS protocols clearly described; and they were written in English, in peer-reviewed journals. Fifteen manuscripts were identified. TMS protocols were heterogeneous across studies. Resting motor threshold, active motor threshold, and amplitudes of motor-evoked potentials were typically reported to be normal in RLS. A reduction in short-interval intracortical inhibition (SICI) was the most consistent finding, whereas conflicting results were described in regard to short-interval intracortical facilitation and the contralateral silent period. Decreased SICI can be reversed by treatment with dopaminergic agonists. Plasticity in the motor cortex and sensorimotor integration may be disrupted. TMS may become a useful biomarker of responsiveness to drug treatment in RLS. The field can benefit from increases in homogeneity and sizes of samples, as well as from decrease in methodological variability across studies.
Collapse
Affiliation(s)
| | | | | | | | - Alan Luiz Eckeli
- Hospital das Clínicas da Faculdade de Medicina da USP, Ribeirão Preto, São Paulo, Brazil
| | | |
Collapse
|
22
|
Kunita K, Fujiwara K. Effect of maintaining neck flexion on anti-saccade reaction time: an investigation using transcranial magnetic stimulation to the frontal oculomotor field. J Physiol Anthropol 2013; 32:21. [PMID: 24220550 PMCID: PMC3831255 DOI: 10.1186/1880-6805-32-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 10/31/2013] [Indexed: 11/30/2022] Open
Abstract
Background Reaction time for anti-saccade, in which the gaze is directed to the position opposite to an illuminated target, shortens during maintenance of neck flexion. The present study applied transcranial magnetic stimulation (TMS) to the frontal oculomotor field, and investigated the effect of maintaining neck flexion on information processing time in the anti-saccade neural pathway before the frontal oculomotor field. Methods The reaction time was measured with the chin resting on a stand (‘chin-on’ condition) and with voluntary maintenance of neck flexion (‘chin-off’ condition) at 80% maximal neck flexion angle, with and without TMS. The TMS timing producing the longest prolongation of the reaction time was first roughly identified for 10 ms intervals from 0 to 180 ms after the target presentation. Thereafter, TMS timing was set finely at 2 ms intervals from −20 to +20 ms of the 10 ms step that produced the longest prolongation. Results The reaction time without TMS was significantly shorter (21.9 ms) for the chin-off (235.9 ± 14.9 ms) than for the chin-on (257.5 ± 17.1 ms) condition. Furthermore, TMS timing producing maximal prolongation of the reaction time was significantly earlier (18.6 ms) for the chin-off than the chin-on condition. The ratio of the forward shift in TMS timing relative to the reduction in reaction time was 87.8%. Conclusions We confirmed that information processing time in the anti-saccade neural pathway before the frontal oculomotor field shortened while neck flexion was maintained, and that this reduction time accounted for approximately 88% of the shortening of reaction time.
Collapse
Affiliation(s)
- Kenji Kunita
- Department of Sports Instruction, Faculty of Sports and Human, Sapporo International University, 4-1-4-1 Kiyota, Kiyota-ku, Sapporo 004-8602, Japan.
| | | |
Collapse
|
23
|
Krieg TD, Salinas FS, Narayana S, Fox PT, Mogul DJ. PET-based confirmation of orientation sensitivity of TMS-induced cortical activation in humans. Brain Stimul 2013; 6:898-904. [PMID: 23827648 PMCID: PMC5293002 DOI: 10.1016/j.brs.2013.05.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Revised: 05/16/2013] [Accepted: 05/25/2013] [Indexed: 10/26/2022] Open
Abstract
BACKGROUND Currently, it is difficult to predict precise regions of cortical activation in response to transcranial magnetic stimulation (TMS). Most analytical approaches focus on applied magnetic field strength in the target region as the primary factor, placing activation on the gyral crowns. However, imaging studies support M1 targets being typically located in the sulcal banks. OBJECTIVE/HYPOTHESIS To more thoroughly investigate this inconsistency, we sought to determine whether neocortical surface orientation was a critical determinant of regional activation. METHODS MR images were used to construct cortical and scalp surfaces for 18 subjects. The angle (θ) between the cortical surface normal and its nearest scalp normal for ~50,000 cortical points per subject was used to quantify cortical location (i.e., gyral vs. sulcal). TMS-induced activations of primary motor cortex (M1) were compared to brain activations recorded during a finger-tapping task using concurrent positron emission tomographic (PET) imaging. RESULTS Brain activations were primarily sulcal for both the TMS and task activations (P < 0.001 for both) compared to the overall cortical surface orientation. Also, the location of maximal blood flow in response to either TMS or finger-tapping correlated well using the cortical surface orientation angle or distance to scalp (P < 0.001 for both) as criteria for comparison between different neocortical activation modalities. CONCLUSION This study provides further evidence that a major factor in cortical activation using TMS is the orientation of the cortical surface with respect to the induced electric field. The results show that, despite the gyral crown of the cortex being subjected to a larger magnetic field magnitude, the sulcal bank of M1 had larger cerebral blood flow (CBF) responses during TMS.
Collapse
Affiliation(s)
- Todd D. Krieg
- Department of Biomedical Engineering, Illinois Institute of Technology, Wishnick Hall 314, 3255 S. Dearborn St., Chicago, IL 60616, USA
| | - Felipe S. Salinas
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Shalini Narayana
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Department of Pediatrics, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Peter T. Fox
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- South Texas Veterans Health Care System, San Antonio, TX, USA
| | - David J. Mogul
- Department of Biomedical Engineering, Illinois Institute of Technology, Wishnick Hall 314, 3255 S. Dearborn St., Chicago, IL 60616, USA
| |
Collapse
|
24
|
Renzi C, Bruns P, Heise KF, Zimerman M, Feldheim JF, Hummel FC, Röder B. Spatial Remapping in the Audio-tactile Ventriloquism Effect: A TMS Investigation on the Role of the Ventral Intraparietal Area. J Cogn Neurosci 2013; 25:790-801. [DOI: 10.1162/jocn_a_00362] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
Previous studies have suggested that the putative human homologue of the ventral intraparietal area (hVIP) is crucially involved in the remapping of tactile information into external spatial coordinates and in the realignment of tactile and visual maps. It is unclear, however, whether hVIP is critical for the remapping process during audio-tactile cross-modal spatial interactions. The audio-tactile ventriloquism effect, where the perceived location of a sound is shifted toward the location of a synchronous but spatially disparate tactile stimulus, was used to probe spatial interactions in audio-tactile processing. Eighteen healthy volunteers were asked to report the perceived location of brief auditory stimuli presented from three different locations (left, center, and right). Auditory stimuli were presented either alone (unimodal stimuli) or concurrently to a spatially discrepant tactile stimulus applied to the left or right index finger (bimodal stimuli), with the hands adopting either an uncrossed or a crossed posture. Single pulses of TMS were delivered over the hVIP or a control site (primary somatosensory cortex, SI) 80 msec after trial onset. TMS to the hVIP, compared with the control SI-TMS, interfered with the remapping of touch into external space, suggesting that hVIP is crucially involved in transforming spatial reference frames across audition and touch.
Collapse
|
25
|
Vitikainen AM, Salli E, Lioumis P, Mäkelä JP, Metsähonkala L. Applicability of nTMS in locating the motor cortical representation areas in patients with epilepsy. Acta Neurochir (Wien) 2013; 155:507-18. [PMID: 23328919 DOI: 10.1007/s00701-012-1609-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 12/27/2012] [Indexed: 11/26/2022]
Abstract
BACKGROUND Transcranial magnetic stimulation (TMS) is increasingly used for non-invasive functional mapping in preoperative evaluation for brain surgery, and the reliability of navigated TMS (nTMS) motor representation maps has been studied in the healthy population and in brain tumor patients. The lesions behind intractable epilepsy differ from typical brain tumors, ranging from developmental cortical malformations to injuries early in development, and may influence the functional organization of the cortical areas. Moreover, the interictal cortical epileptic activity and antiepileptic medication may affect the nTMS motor threshold. The reliability of the nTMS motor representation localization in epilepsy patients has not been addressed. METHODS We compared the nTMS motor cortical representation maps of hand and arm muscles with the results of invasive electrical cortical stimulation (ECS) in 13 patients with focal epilepsy. The nTMS maps were projected to the cortical surface segmented from preoperative magnetic resonance images (MRI), and the positions of the subdural electrodes were extracted from the postoperative low-dose computed tomography (CT) images registered with preoperative MRI. RESULTS The 3D distance between the average nTMS site and average ECS electrode location was 11 ± 4 mm for the hand and 16 ± 7 mm for arm muscle representation areas. In all patients the representation areas defined with nTMS and ECS were located on the same gyrus, also in patients with abundant interictal epileptic activity on the motor gyrus. CONCLUSIONS nTMS can reliably locate the hand motor cortical representation area with the accuracy needed for pre-surgical evaluation in patients with epilepsy.
Collapse
MESH Headings
- Adolescent
- Adult
- Arm/innervation
- Brain Mapping/methods
- Brain Neoplasms/physiopathology
- Brain Neoplasms/surgery
- Child
- Electric Stimulation
- Electromyography
- Epilepsies, Partial/physiopathology
- Epilepsies, Partial/surgery
- Epilepsy, Frontal Lobe/physiopathology
- Epilepsy, Frontal Lobe/surgery
- Epilepsy, Partial, Motor/physiopathology
- Epilepsy, Partial, Motor/surgery
- Hand/innervation
- Humans
- Image Interpretation, Computer-Assisted/methods
- Imaging, Three-Dimensional
- Magnetic Resonance Imaging/methods
- Male
- Motor Cortex/physiopathology
- Muscle, Skeletal/innervation
- Preoperative Care/methods
- Retrospective Studies
- Somatosensory Cortex/physiopathology
- Tomography, X-Ray Computed/methods
- Transcranial Magnetic Stimulation/methods
- Young Adult
Collapse
Affiliation(s)
- Anne-Mari Vitikainen
- Department of Radiology, HUS Medical Imaging Center, Helsinki University Central Hospital and University of Helsinki, P.O. Box 340, 00029, Helsinki, Finland.
| | | | | | | | | |
Collapse
|
26
|
Weiss C, Nettekoven C, Rehme AK, Neuschmelting V, Eisenbeis A, Goldbrunner R, Grefkes C. Mapping the hand, foot and face representations in the primary motor cortex — Retest reliability of neuronavigated TMS versus functional MRI. Neuroimage 2013; 66:531-42. [DOI: 10.1016/j.neuroimage.2012.10.046] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 10/11/2012] [Accepted: 10/19/2012] [Indexed: 12/15/2022] Open
|
27
|
Rottler P, Schroeder HWS, Lotze M. Outcome-dependent coactivation of lip and tongue primary somatosensory representation following hypoglossal-facial transfer after peripheral facial palsy. Hum Brain Mapp 2012; 35:638-45. [PMID: 23124599 DOI: 10.1002/hbm.22206] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Revised: 08/17/2012] [Accepted: 09/04/2012] [Indexed: 11/07/2022] Open
Abstract
A hypoglossal-facial transfer is a common surgical strategy for reanimating the face after persistent total hemifacial palsy. We were interested in how motor recovery is associated with cortical reorganization of lip and tongue representation in the primary sensorimotor cortex after the transfer. Therefore, we used functional magnetic resonance imaging (fMRI) in 13 patients who underwent a hypoglossal-facial transfer after unilateral peripheral facial palsy. To identify primary motor and somatosensory tongue and lip representation sites, we measured repetitive tongue and lip movements during fMRI. Electromyography (EMG) of the perioral muscles during tongue and lip movements and standardized evaluation of lip elevation served as outcome parameters. We found an association of cortical representation sites in the pre- and postcentral gyrus (decreased distance of lip and tongue representation) with symmetry of recovered lip movements (lip elevation) and coactivation of the lip during voluntary tongue movements (EMG-activity of the lip during tongue movements). Overall, our study shows that hypoglossal-facial transfer resulted in an outcome-dependent cortical reorganization with activation of the cortical tongue area for restituded movement of the lip.
Collapse
Affiliation(s)
- Philipp Rottler
- Functional Imaging Department, Institute of Diagnostic Radiology and Neuroradiology, University of Greifswald, Germany; Department of Neurosurgery, University of Greifswald, Greifswald, Germany
| | | | | |
Collapse
|
28
|
Motor map reliability and aging: a TMS/fMRI study. Exp Brain Res 2012; 219:97-106. [PMID: 22466408 DOI: 10.1007/s00221-012-3070-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 03/06/2012] [Indexed: 01/13/2023]
Abstract
This study compared the reliability of motor maps over 3 sessions from both neuronavigated transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) data between younger and older adults. Seven younger (ages 19-31) and seven older (ages 64-76) adults participated in three joint TMS/fMRI assessment sessions separated by 7 or 14 days. Sessions involved mapping of the right first dorsal interosseous muscle using single-pulse TMS immediately followed by block-design fMRI scanning involving volitional right-hand index finger to thumb oppositional squeeze. Intersession reliability of map volume, evaluated by intraclass correlation and Jaccard Coefficient between testing sessions, was more consistent for younger adults in both fMRI and TMS. A positive correlation was evidenced between fMRI and TMS map volumes and Jaccard Coefficients indicating spatial consistency across sessions between the two measures. Comparisons of map reliability between age groups showed that younger adults have more stable motor maps in both fMRI and TMS. fMRI and TMS maps show consistency across modalities. Future interpretation of motor maps should attempt to account for potential increased variability of such mapping in older age groups. Despite these age group differences in reliability, fMRI and TMS appear to offer consistent and complementary information about cortical representation of the first dorsal interosseous muscle.
Collapse
|
29
|
Bradfield NI, Reutens DC, Chen J, Wood AG. Stereotaxic localisation of the dorsolateral prefrontal cortex for transcranial magnetic stimulation is superior to the standard reference position. Aust N Z J Psychiatry 2012; 46:232-9. [PMID: 22391280 DOI: 10.1177/0004867411430602] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE To determine whether the standard method of localisation of the dorsolateral prefrontal cortex for repetitive transcranial magnetic stimulation is accurate and reliable, and to develop an empirically based method for operational localisation of the dorsolateral prefrontal cortex with reference to the motor hand area. METHOD We compared stereotaxic localisation of the dorsolateral prefrontal cortex with the commonly used operational definition of 6 cm anterior to the site of the abductor pollicis brevis muscle in healthy participants (n = 18). We also report the average translational distance from the site of the abductor pollicis brevis to the stereotaxically defined dorsolateral prefrontal cortex. RESULTS The stereotaxic method was less variable than the operational method of localisation and more frequently targeted the middle frontal gyrus. The average translational distance from the site of the abductor pollicis brevis to the stereotaxically targeted dorsolateral prefrontal cortex was x = -5 mm, y = 53 mm and z = -31 mm. CONCLUSIONS Operational localisation of the dorsolateral prefrontal cortex for repetitive transcranial magnetic stimulation with reference to the motor hand area is more variable than stereotaxic localisation. If future studies choose to use an operational definition of the left dorsolateral prefrontal cortex, we suggest it should be 5 mm lateral, 53 mm anterior and 31 mm inferior to the site of the abductor pollicis brevis.
Collapse
|
30
|
Picht T, Schulz J, Hanna M, Schmidt S, Suess O, Vajkoczy P. Assessment of the Influence of Navigated Transcranial Magnetic Stimulation on Surgical Planning for Tumors in or Near the Motor Cortex. Neurosurgery 2011; 70:1248-56; discussion 1256-7. [DOI: 10.1227/neu.0b013e318243881e] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Abstract
BACKGROUND:
Brain tumor surgery near the motor cortex requires careful planning to achieve the optimal balance between completeness of tumor resection and preservation of motor function. Navigated transcranial magnetic stimulation (nTMS) can be used to map functionally essential motor areas preoperatively.
OBJECTIVE:
To evaluate how much influence, benefit, and impact nTMS has on the surgical planning for tumors near the motor cortex.
METHODS:
This study reviewed the records of 73 patients with brain tumors in or near the motor cortex, mapped preoperatively with nTMS. The surgical team prospectively classified how much influence the nTMS results had on the surgical planning. Stepwise regression analysis was used to explore which factors predict the amount of influence, benefit, and impact nTMS has on the surgical planning.
RESULTS:
The influence of nTMS on the surgical planning was as follows: it confirmed the expected anatomy in 22% of patients, added knowledge that was not used in 23%, added awareness of high-risk areas in 27%, modified the approach in 16%, changed the planned extent of resection in 8%, and changed the surgical indication in 3%.
CONCLUSION:
nTMS had an objective benefit on the surgical planning in one fourth of the patients and a subjective benefit in an additional half of the patients. It had an impact on the surgery itself in just more than half of the patients. By mapping the spatial relationship between the tumor and functional motor cortex, nTMS improves surgical planning for tumors in or near the motor cortex.
Collapse
Affiliation(s)
- Thomas Picht
- Department of Neurosurgery, Charité University Hospital, Berlin, Germany
| | - Juliane Schulz
- Department of Neurosurgery, Charité University Hospital, Berlin, Germany
| | - Michael Hanna
- Mercury Medical Research and Writing, Berlin, Germany
| | - Sein Schmidt
- Department of Neurology, Charité University Hospital, Berlin, Germany
| | - Olaf Suess
- Department of Neurosurgery, Charité University Hospital, Berlin, Germany
- Now at the Center for Spine Surgery and Neurotraumatology, DRK Hospitals Berlin–Westend, Berlin, Germany
| | - Peter Vajkoczy
- Department of Neurosurgery, Charité University Hospital, Berlin, Germany
| |
Collapse
|
31
|
Koenraadt KLM, Munneke MAM, Duysens J, Keijsers NLW. TMS: a navigator for NIRS of the primary motor cortex? J Neurosci Methods 2011; 201:142-8. [PMID: 21835198 DOI: 10.1016/j.jneumeth.2011.07.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 07/13/2011] [Accepted: 07/25/2011] [Indexed: 11/19/2022]
Abstract
Near-infrared spectroscopy (NIRS) is a non-invasive optical imaging technique, which is increasingly used to measure hemodynamic responses in the motor cortex. The location at which the NIRS optodes are placed on the skull is a major factor in measuring the hemodynamic responses optimally. In this study, the validity of using transcranial magnetic stimulation (TMS) in combination with a 3D motion analysis system to relocate the TMS derived position was tested. In addition, the main goal was to quantify the advantage of using TMS to locate the optimal position in relation to the most commonly used EEG C3 position. Markers were placed on the TMS coil and on the head of the subject. In eleven subjects, a TMS measurement was performed to determine the individual motor-evoked potential center-of-gravity (MEP-CoG). This procedure was repeated in nine subjects to test the validity. Subsequently, hemodynamic responses were measured at the MEP-CoG position and at the C3 position during a thumb abduction and adduction task. On average, the MEP-CoG location was located 19.2mm away from the C3 position. The reproducibility study on the MEP-CoG relocation procedure revealed no systematic relocations. No differences in early and delayed hemodynamic responses were found between the C3 and MEP-CoG position. These results indicate that using TMS for NIRS optodes positioning on the motor cortex does not result in higher hemodynamic response amplitudes. This could be explained if NIRS and TMS assess slightly different functions.
Collapse
Affiliation(s)
- K L M Koenraadt
- Sint Maartenskliniek Nijmegen, Department of Research, Development, and Education, PO Box 9011, 6500 GM Nijmegen, The Netherlands.
| | | | | | | |
Collapse
|
32
|
Diekhoff S, Uludağ K, Sparing R, Tittgemeyer M, Cavuşoğlu M, von Cramon DY, Grefkes C. Functional localization in the human brain: Gradient-Echo, Spin-Echo, and arterial spin-labeling fMRI compared with neuronavigated TMS. Hum Brain Mapp 2011; 32:341-57. [PMID: 20533563 DOI: 10.1002/hbm.21024] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A spatial mismatch of up to 14 mm between optimal transcranial magnetic stimulation (TMS) site and functional magnetic resonance imaging (fMRI) signal has consistently been reported for the primary motor cortex. The underlying cause might be the effect of magnetic susceptibility around large draining veins in Gradient-Echo blood oxygenation level-dependent (GRE-BOLD) fMRI. We tested whether alternative fMRI sequences such as Spin-Echo (SE-BOLD) or Arterial Spin-Labeling (ASL) assessing cerebral blood flow (ASL-CBF) may localize neural activity closer to optimal TMS positions and primary motor cortex than GRE-BOLD. GRE-BOLD, SE-BOLD, and ASL-CBF signal changes during right thumb abductions were obtained from 15 healthy subjects at 3 Tesla. In 12 subjects, tissue at fMRI maxima was stimulated with neuronavigated TMS to compare motor-evoked potentials (MEPs). Euclidean distances between the fMRI center-of-gravity (CoG) and the TMS motor mapping CoG were calculated. Highest SE-BOLD and ASL-CBF signal changes were located in the anterior wall of the central sulcus [Brodmann Area 4 (BA4)], whereas highest GRE-BOLD signal changes were significantly closer to the gyral surface. TMS at GRE-BOLD maxima resulted in higher MEPs which might be attributed to significantly higher electric field strengths. TMS-CoGs were significantly anterior to fMRI-CoGs but distances were not statistically different across sequences. Our findings imply that spatial differences between fMRI and TMS are unlikely to be caused by spatial unspecificity of GRE-BOLD fMRI but might be attributed to other factors, e.g., interactions between TMS-induced electric field and neural tissue. Differences between techniques should be kept in mind when using fMRI coordinates as TMS (intervention) targets.
Collapse
Affiliation(s)
- Svenja Diekhoff
- Max Planck Institute for Neurological Research, Cologne, Germany
| | | | | | | | | | | | | |
Collapse
|
33
|
Threshold curves for transcranial magnetic stimulation to improve reliability of motor pathway status assessment. Clin Neurophysiol 2011; 122:975-83. [DOI: 10.1016/j.clinph.2010.09.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Revised: 09/07/2010] [Accepted: 09/08/2010] [Indexed: 11/21/2022]
|
34
|
Sarfeld AS, Diekhoff S, Wang LE, Liuzzi G, Uludağ K, Eickhoff SB, Fink GR, Grefkes C. Convergence of human brain mapping tools: neuronavigated TMS parameters and fMRI activity in the hand motor area. Hum Brain Mapp 2011; 33:1107-23. [PMID: 21520346 DOI: 10.1002/hbm.21272] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Revised: 12/16/2010] [Accepted: 01/03/2011] [Indexed: 11/09/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) are well-established tools for investigating the human motor system in-vivo. We here studied the relationship between movement-related fMRI signal changes in the primary motor cortex (M1) and electrophysiological properties of the hand motor area assessed with neuronavigated TMS in 17 healthy subjects. The voxel showing the highest task-related BOLD response in the left hand motor area during right hand movements was identified for each individual subject. This fMRI peak voxel in M1 served as spatial target for coil positioning during neuronavigated TMS. We performed correlation analyses between TMS parameters, BOLD signal estimates and effective connectivity parameters of M1 assessed with dynamic causal modeling (DCM). The results showed a negative correlation between the movement-related BOLD signal in left M1 and resting as well as active motor threshold (MT) obtained for left M1. The DCM analysis revealed that higher excitability of left M1 was associated with a stronger coupling between left supplementary motor area (SMA) and M1. Furthermore, BOLD activity in left M1 correlated with ipsilateral silent period (ISP), i.e. the stronger the task-related BOLD response in left M1, the higher interhemispheric inhibition effects targeting right M1. DCM analyses revealed a positive correlation between the coupling of left SMA with left M1 and the duration of ISP. The data show that TMS parameters assessed for the hand area of M1 do not only reflect the intrinsic properties at the stimulation site but also interactions with remote areas in the human motor system.
Collapse
Affiliation(s)
- Anna-Sophia Sarfeld
- Neuromodulation and Neurorehabilitation, Max Planck Institute for Neurological Research, Cologne, Germany
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Niskanen E, Julkunen P, Säisänen L, Vanninen R, Karjalainen P, Könönen M. Group-level variations in motor representation areas of thenar and anterior tibial muscles: Navigated Transcranial Magnetic Stimulation Study. Hum Brain Mapp 2010; 31:1272-80. [PMID: 20082330 DOI: 10.1002/hbm.20942] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Navigated transcranial magnetic stimulation (TMS) can be used to stimulate functional cortical areas at precise anatomical location to induce measurable responses. The stimulation has commonly been focused on anatomically predefined motor areas: TMS of that area elicits a measurable muscle response, the motor evoked potential. In clinical pathologies, however, the well-known homunculus somatotopy theory may not be straightforward, and the representation area of the muscle is not fixed. Traditionally, the anatomical locations of TMS stimulations have not been reported at the group level in standard space. This study describes a methodology for group-level analysis by investigating the normal representation areas of thenar and anterior tibial muscle in the primary motor cortex. The optimal representation area for these muscles was mapped in 59 healthy right-handed subjects using navigated TMS. The coordinates of the optimal stimulation sites were then normalized into standard space to determine the representation areas of these muscles at the group-level in healthy subjects. Furthermore, 95% confidence interval ellipsoids were fitted into the optimal stimulation site clusters to define the variation between subjects in optimal stimulation sites. The variation was found to be highest in the anteroposterior direction along the superior margin of the precentral gyrus. These results provide important normative information for clinical studies assessing changes in the functional cortical areas because of plasticity of the brain. Furthermore, it is proposed that the presented methodology to study TMS locations at the group level on standard space will be a suitable tool for research purposes in population studies.
Collapse
Affiliation(s)
- Eini Niskanen
- Department of Clinical Neurophysiology, Kuopio University Hospital, Finland.
| | | | | | | | | | | |
Collapse
|
36
|
Impact of the gyral geometry on the electric field induced by transcranial magnetic stimulation. Neuroimage 2010; 54:234-43. [PMID: 20682353 DOI: 10.1016/j.neuroimage.2010.07.061] [Citation(s) in RCA: 270] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 07/21/2010] [Accepted: 07/23/2010] [Indexed: 11/23/2022] Open
Abstract
The spatial extent of the effects of transcranial magnetic stimulation (TMS) on neural tissue is only coarsely understood. One key problem is the realistic calculation of the electric field induced in the brain, which proves difficult due to the complex gyral folding pattern that results in an inhomogeneous conductivity distribution within the skull. We used the finite element method (FEM) together with a high-resolution volume mesh of the human head to better characterize the field induced in cortical gray matter (GM). The volume mesh was constructed from T1-weighted structural magnetic resonance images to allow for an anatomically accurate modeling of the gyrification pattern. Five tissue types were taken into account, corresponding to skin, skull, cerebrospinal fluid (CSF) including the ventricles as well as cortical gray and white matter. We characterized the effect of the current direction on the electric field distribution in GM. Importantly, the field strength in GM was increased by up to 51% when the induced currents were perpendicular to the local gyrus orientation. This effect was mainly restricted to the gyral crowns and lips, but did not extend into the sulcal walls. As a result, the focality of the fields induced in GM was increased. This enhancement effect might in part underlie the dependency of stimulation thresholds on coil orientation, as commonly observed in TMS motor cortex studies. In contrast to the clear-cut effects of the gyrification pattern on the induced field strength, current directions were predominantly influenced by the CSF-skull boundary.
Collapse
|
37
|
Kantelhardt SR, Fadini T, Finke M, Kallenberg K, Siemerkus J, Bockermann V, Matthaeus L, Paulus W, Schweikard A, Rohde V, Giese A. Robot-assisted image-guided transcranial magnetic stimulation for somatotopic mapping of the motor cortex: a clinical pilot study. Acta Neurochir (Wien) 2010; 152:333-43. [PMID: 19943069 PMCID: PMC2815301 DOI: 10.1007/s00701-009-0565-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Accepted: 11/03/2009] [Indexed: 11/28/2022]
Abstract
Purpose Shape and exact location of motor cortical areas varies among individuals. The exact knowledge of these locations is crucial for planning of neurosurgical procedures. In this study, we have used robot-assisted image-guided transcranial magnetic stimulation (Ri-TMS) to elicit MEP response recorded for individual muscles and reconstruct functional motor maps of the primary motor cortex. Methods One healthy volunteer and five patients with intracranial tumors neighboring the precentral gyrus were selected for this pilot study. Conventional MRI and fMRI were obtained. Transcranial magnetic stimulation was performed using a MagPro X100 stimulator and a standard figure-of-eight coil positioned by an Adept Viper s850 robot. The fMRI activation/Ri-TMS response pattern were compared. In two cases, Ri-TMS was additionally compared to intraoperative direct electrical cortical stimulation. Results Maximal MEP response of the m. abductor digiti minimi was located in an area corresponding to the “hand knob” of the precentral gyrus for both hemispheres. Repeated Ri-TMS measurements showed a high reproducibility. Simultaneous registration of the MEP response for m. brachioradialis, m. abductor pollicis brevis, and m. abductor digiti minimi demonstrated individual peak areas of maximal MEP response for the individual muscle groups. Ri-TMS mapping was compared to the corresponding fMRI studies. The areas of maximal MEP response localized within the “finger tapping” activated areas by fMRI in all six individuals. Conclusions Ri-TMS is suitable for high resolution non-invasive preoperative somatotopic mapping of the motor cortex. Ri-TMS may help in the planning of neurosurgical procedures and may be directly used in navigation systems.
Collapse
Affiliation(s)
- Sven Rainer Kantelhardt
- Department of Neurosurgery, Georg-August University of Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany
| | - Tommaso Fadini
- Department of Clinical Neurophysiology, Georg-August University of Göttingen, Göttingen, Germany
| | - Markus Finke
- Institute for Robotics und Cognitive Systems, University of Lübeck, Lübeck, Germany
| | - Kai Kallenberg
- Department of Neuroradiology, Georg-August University of Göttingen, Göttingen, Germany
- MR-Research in Neurology and Psychiatry, Georg-August University of Göttingen, Göttingen, Germany
| | - Jakob Siemerkus
- MR-Research in Neurology and Psychiatry, Georg-August University of Göttingen, Göttingen, Germany
| | - Volker Bockermann
- Department of Neurosurgery, Georg-August University of Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany
| | - Lars Matthaeus
- Institute for Robotics und Cognitive Systems, University of Lübeck, Lübeck, Germany
| | - Walter Paulus
- Department of Clinical Neurophysiology, Georg-August University of Göttingen, Göttingen, Germany
| | - Achim Schweikard
- Institute for Robotics und Cognitive Systems, University of Lübeck, Lübeck, Germany
| | - Veit Rohde
- Department of Neurosurgery, Georg-August University of Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany
| | - Alf Giese
- Department of Neurosurgery, Georg-August University of Göttingen, Robert-Koch-Strasse 40, 37075 Göttingen, Germany
| |
Collapse
|
38
|
Inuggi A, Filippi M, Chieffo R, Agosta F, Rocca MA, González-Rosa JJ, Cursi M, Comi G, Leocani L. Motor area localization using fMRI-constrained cortical current density reconstruction of movement-related cortical potentials, a comparison with fMRI and TMS mapping. Brain Res 2010; 1308:68-78. [DOI: 10.1016/j.brainres.2009.10.042] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 10/15/2009] [Accepted: 10/16/2009] [Indexed: 11/29/2022]
|
39
|
Caramia F, Francia A, Mainero C, Tinelli E, Palmieri MG, Colonnese C, Bozzao L, Caramia MD. Neurophysiological and functional MRI evidence of reorganization of cortical motor areas in cerebral arteriovenous malformation. Magn Reson Imaging 2009; 27:1360-9. [DOI: 10.1016/j.mri.2009.05.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Revised: 04/03/2009] [Accepted: 05/07/2009] [Indexed: 10/20/2022]
|
40
|
Efficacy of 2 non-weight-bearing interventions, proprioception training versus strength training, for patients with knee osteoarthritis: a randomized clinical trial. J Orthop Sports Phys Ther 2009; 39:450-7. [PMID: 19531879 DOI: 10.2519/jospt.2009.2923] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
STUDY DESIGN Randomized clinical trial. OBJECTIVE To investigate the clinical and functional efficacy of 2 different non-weight-bearing exercise regimens, proprioceptive training (PrT) versus strength training (ST), for patients with knee osteoarthritis (OA). BACKGROUND Both strength and proprioceptive training are important interventions for individuals with knee OA. The benefits of weight-bearing exercises are generally recognized in the clinical setting. However, exercising in a standing or weight-bearing position may aggravate symptoms in patients with knee OA. METHODS AND MEASURES One hundred eight patients were randomly assigned to the PrT, ST, or no exercise (control) group for an 8-week intervention. Both the PrT and ST interventions consisted of non-weight-bearing exercises. Western Ontario and McMaster Universities Osteoarthritis Index-pain (WOMAC-pain) and -function scores, walking time on 3 different terrains, knee strength, and absolute knee reposition error were assessed before and after intervention. Data were analyzed using mixed-model ANOVAs. RESULTS Both PrT and ST significantly improved WOMAC-pain and -function score after intervention (P<.008). The improvement secondary to ST in the WOMAC-function scores (17.2 points) and for knee extension strength (10.3-14.9 Nm) was greater than the minimally clinically important difference for these measurements. The PrT group demonstrated greater improvement in walking time on a spongy surface and knee reposition error than the other 2 groups. No improvements were apparent in the control group. CONCLUSION Both types of non-weight-bearing exercises (PrT and ST) significantly improved outcomes in this study. PrT led to greater improvements in proprioceptive function, while ST resulted in a greater increase in knee extensor muscle strength.
Collapse
|
41
|
Determining the cortical target of transcranial magnetic stimulation. Neuroimage 2009; 47:1319-30. [PMID: 19371785 DOI: 10.1016/j.neuroimage.2009.04.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Revised: 03/09/2009] [Accepted: 04/01/2009] [Indexed: 11/23/2022] Open
Abstract
Determining the cortical region that is effectively targeted by TMS to induce a reproducible behavioral effect is a non-trivial problem. In mapping experiments, a grid of coil positions is used to systematically assess the TMS effect on, e.g. muscle responses or error rates. The center-of-mass (CoM) of the response distribution is projected onto the cortex to determine the likely target site, implicitly assuming the existence of a single, contiguous target. The mapping results, however, often contain several local maxima. These could either stem from measurement noise, or hint towards a distributed target region. Critically, the calculation of a CoM, by design, treats multiple maxima as if they were noise. Here, a stringent hierarchical sigmoidal model fitting approach is developed that determines the cortical target(s) from TMS mapping based on electric field calculations. Monte-Carlo simulations are used to assess the significance and the goodness-of-fit of the sigmoidal fits, and to obtain confidence regions around the calculated targets. The approach was applied to mapping data on visual suppression (N=7). In all subjects, we reliably identified two or three neighboring targets commonly contributing to the suppression effect (average distance+/-SD: 7.7+/-2.3 mm). This demonstrates that (i) the assumption of a single CoM is not generally valid and (ii) the combination of TMS mapping with the fitting approach has a cortical resolution of <1 cm. The estimates for the field strength necessary to achieve 50% of the maximal suppression effect vary noticeably across subjects (mean+/-SD: 139+/-24 V/m), indicating inter-individual differences in the susceptibility to TMS.
Collapse
|
42
|
A triangulation-based magnetic resonance image-guided method for transcranial magnetic stimulation coil positioning. Brain Stimul 2009; 2:123-31. [PMID: 20633411 DOI: 10.1016/j.brs.2008.10.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2007] [Revised: 10/29/2008] [Accepted: 10/30/2008] [Indexed: 11/23/2022] Open
Abstract
Transcranial magnetic stimulation (TMS) is currently used for cognitive studies and investigated as a treatment for psychiatric disorders. Because of the cortex variability, the coil positioning stage is difficult and should be improved by using individual neuroimaging data. Sophisticated and expensive neuronavigation systems have been developed to guide the coil to selected regions on the patient's magnetic resonance images (MRI). Our objective was to develop a triangulation-based MRI-guided method to position manually the TMS coil over the subject's head, using a cortical target derived from individual MR data. We evaluated both the spatial accuracy and the reproducibility of the method using functional MR activations of two different targets in the motor and parietal cortices. The accuracy of the MRI-guided method, assessed from the Euclidean distance (D(m)) between the thumb motor target and the coil position eliciting reproducible thumb motor-evoked potentials with TMS, was D(m) = 10 +/- 3 mm. The reproducibility of the method, evaluated across two different operators, was D(m) = 6.7 +/- 1.4 mm for the repositioning in the motor cortex and D(m) = 6.0 +/- 3.2 mm in the parietal cortex. This novel method could be used clinically to assist positioning of the TMS coil.
Collapse
|
43
|
Collignon O, Davare M, De Volder AG, Poirier C, Olivier E, Veraart C. Time-course of posterior parietal and occipital cortex contribution to sound localization. J Cogn Neurosci 2008; 20:1454-63. [PMID: 18303980 DOI: 10.1162/jocn.2008.20102] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
It has been suggested that both the posterior parietal cortex (PPC) and the extrastriate occipital cortex (OC) participate in the spatial processing of sounds. However, the precise time-course of their contribution remains unknown, which is of particular interest, considering that it could give new insights into the mechanisms underlying auditory space perception. To address this issue, we have used event-related transcranial magnetic stimulation (TMS) to induce virtual lesions of either the right PPC or right OC at different delays in subjects performing a sound lateralization task. Our results confirmed that these two areas participate in the spatial processing of sounds. More precisely, we found that TMS applied over the right OC 50 msec after the stimulus onset significantly impaired the localization of sounds presented either to the right or to the left side. Moreover, right PPC virtual lesions induced 100 and 150 msec after sound presentation led to a rightward bias for stimuli delivered on the center and on the left side, reproducing transiently the deficits commonly observed in hemineglect patients. The finding that the right OC is involved in sound processing before the right PPC suggests that the OC exerts a feedforward influence on the PPC during auditory spatial processing.
Collapse
Affiliation(s)
- Olivier Collignon
- Neural Rehabilitation Engineering Laboratory, Université Catholique de Louvain, Brussels, Belgium.
| | | | | | | | | | | |
Collapse
|
44
|
Muscles in "concert": study of primary motor cortex upper limb functional topography. PLoS One 2008; 3:e3069. [PMID: 18728785 PMCID: PMC2518106 DOI: 10.1371/journal.pone.0003069] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2008] [Accepted: 07/28/2008] [Indexed: 12/05/2022] Open
Abstract
Background Previous studies with Transcranial Magnetic Stimulation (TMS) have focused on the cortical representation of limited group of muscles. No attempts have been carried out so far to get simultaneous recordings from hand, forearm and arm with TMS in order to disentangle a ‘functional’ map providing information on the rules orchestrating muscle coupling and overlap. The aim of the present study is to disentangle functional associations between 12 upper limb muscles using two measures: cortical overlapping and cortical covariation of each pair of muscles. Interhemispheric differences and the influence of posture were evaluated as well. Methodology/Principal Findings TMS mapping studies of 12 muscles belonging to hand, forearm and arm were performed. Findings demonstrate significant differences between the 66 pairs of muscles in terms of cortical overlapping: extremely high for hand-forearm muscles and very low for arm vs hand/forearm muscles. When right and left hemispheres were compared, overlapping between all possible pairs of muscles in the left hemisphere (62.5%) was significantly higher than in the right one (53.5% ). The arm/hand posture influenced both measures of cortical association, the effect of Position being significant [p = .021] on overlapping, resulting in 59.5% with prone vs 53.2% with supine hand, but only for pairs of muscles belonging to hand and forearm, while no changes occurred in the overlapping of proximal muscles with those of more distal districts. Conclusions/Significance Larger overlapping in the left hemisphere could be related to its lifetime higher training of all twelve muscles studied with respect to the right hemisphere, resulting in larger intra-cortical connectivity within primary motor cortex. Altogether, findings with prone hand might be ascribed to mechanisms facilitating coupling of muscles for object grasping and lifting -with more proximal involvement for joint stabilization- compared to supine hand facilitating actions like catching. TMS multiple-muscle mapping studies permit a better understanding of motor control and ‘plastic’ reorganization of motor system.
Collapse
|
45
|
Tsao H, Galea MP, Hodges PW. Reorganization of the motor cortex is associated with postural control deficits in recurrent low back pain. Brain 2008; 131:2161-71. [DOI: 10.1093/brain/awn154] [Citation(s) in RCA: 306] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
46
|
Forner-Cordero A, Steyvers M, Levin O, Alaerts K, Swinnen SP. Changes in corticomotor excitability following prolonged muscle tendon vibration. Behav Brain Res 2008; 190:41-9. [PMID: 18378327 DOI: 10.1016/j.bbr.2008.02.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 01/13/2008] [Accepted: 02/04/2008] [Indexed: 11/28/2022]
Affiliation(s)
- Arturo Forner-Cordero
- Motor Control Laboratory, Department of Biomedical Kinesiology, Group Biomedical Sciences, Katholieke Universiteit Leuven, Belgium.
| | | | | | | | | |
Collapse
|
47
|
Davare M, Lemon R, Olivier E. Selective modulation of interactions between ventral premotor cortex and primary motor cortex during precision grasping in humans. J Physiol 2008; 586:2735-42. [PMID: 18403420 DOI: 10.1113/jphysiol.2008.152603] [Citation(s) in RCA: 170] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In humans, the rostral part of the ventral premotor cortex (PMv), the homologue of F5 in monkeys, is known to be critically involved in shaping the hand to grasp objects. How does information about hand posture, that is processed in PMv, give rise to appropriate motor commands for transmission to spinal circuits controlling the hand? Whereas PMv is crucial for skilled visuomotor control of the hand, PMv sends relatively few direct corticospinal projections to spinal segments innervating hand muscles and the most likely route for PMv to contribute to the control of hand shape is through cortico-cortical connections with primary motor cortex (M1). If this is the case, we predicted that PMv-M1 interactions should be modulated specifically during precision grasping in humans. To address this issue, we investigated PMv-M1 connections by means of paired-pulse transcranial magnetic stimulation (TMS) and compared whether they were differentially modulated at rest, and during precision versus power grip. To do so, TMS was applied over M1 either in isolation or after a conditioning stimulus delivered, at different delays, over the ipsilateral PMv. For the parameters of TMS tested, we found that, at rest, PMv exerted a net inhibitory influence on M1 whereas, during power grip, this inhibition disappeared and was converted into a net facilitation during precision grip. The finding that, in humans, PMv-M1 interactions are selectively modulated during specific types of grasp provides further evidence that these connections play an important role in control of the hand.
Collapse
Affiliation(s)
- Marco Davare
- Laboratory of Neurophysiology, Université catholique de Louvain, Avenue Hippocrate 54, B-1200 Brussels, Belgium
| | | | | |
Collapse
|
48
|
Sparing R, Buelte D, Meister IG, Paus T, Fink GR. Transcranial magnetic stimulation and the challenge of coil placement: a comparison of conventional and stereotaxic neuronavigational strategies. Hum Brain Mapp 2008; 29:82-96. [PMID: 17318831 PMCID: PMC6871049 DOI: 10.1002/hbm.20360] [Citation(s) in RCA: 213] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2006] [Revised: 11/13/2006] [Accepted: 12/07/2006] [Indexed: 11/07/2022] Open
Abstract
The combination of transcranial magnetic stimulation (TMS) with functional neuroimaging has expanded the potential of TMS for human brain mapping. The precise and reliable positioning of the TMS coil is not a simple task, however. Modern frameless stereotaxic systems allow investigators to base navigation either on the subject's structural magnetic resonance imaging (MRI), functional MRI data, or the use of functional neuroimaging data from the literature, so-called "probabilistic approach." The latter assumes consistency across individuals in the location of task-related "activations" in standardized stereotaxic space. Conventional nonstereotaxic localization of brain areas is also a common method for defining the coil position. Our aim was to evaluate the accuracy of five different localization strategies in one single study. The left primary motor cortex (left M1-Hand) was used as target region. Three approaches were based on real-time frameless stereotaxy using information based on either anatomical or functional MRI. The remaining two strategies relied either on standard cranial landmarks (i.e., the International 10-20 EEG system) or a standardized function-guided procedure (i.e., the spatial relationship between the left and right M1-Hand). The results were compared to a TMS-based mapping of the primary motor cortex; center of gravity of motor-evoked potentials (MEP-CoG) was calculated for each subject (n = 10). Our findings suggest that highest precision can be achieved with fMRI-guided stimulation, which was accurate within the range of millimeters. Very consistent results were also obtained with the "probabilistic" approach. In view of these findings, we discuss the methods and special characteristics of each localization strategy.
Collapse
Affiliation(s)
- Roland Sparing
- Department of Medicine, Institute of Neuroscience and Biophysics, Research Center Juelich, Juelich, Germany.
| | | | | | | | | |
Collapse
|
49
|
Efficacy of a target-matching foot-stepping exercise on proprioception and function in patients with knee osteoarthritis. J Orthop Sports Phys Ther 2008; 38:19-25. [PMID: 18357655 DOI: 10.2519/jospt.2008.2512] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
STUDY DESIGN A randomized clinical trial design. OBJECTIVE To investigate the efficacy of high, repetitive, target-matching foot-stepping exercise (TMFSE) performed in a sitting position on proprioception, functional score, and walking velocity for patients with knee osteoarthritis (OA). BACKGROUND Researchers have suggested that exercises to address knee OA should include proprioceptive training. However, most patients cannot tolerate conventional proprioceptive training performed in a standing position. METHODS AND MEASURES Forty-nine subjects (mean age +/- SD, 63.3 +/- 8.1) with knee OA were randomly assigned to the exercise or no intervention groups. The exercise group practiced TMFSE in sitting, 3 sessions weekly for 6 weeks. All subjects underwent assessments of knee reposition error, functional incapacity score, and walking velocity prior to and after intervention. RESULTS The TMFSE significantly improved reposition error from a mean +/- SD of 3.0 degrees +/- 1.6 degrees to 1.5 degrees +/- 0.6 degree, walking velocity on ground level from 44.1 +/- 2.9 to 38.6 +/- 2.5 sec for 60 meters, time to complete a stairs task from 34.2 +/- 2.1 to 26.5 +/- 2.3 seconds, time to complete a figure-of-eight from 51.3 +/- 6.7 to 29.1 +/- 3.6 seconds, and score on a functional incapacity scale from 12.0 +/- 3.1 to 4.9 +/- 1.7, in subjects with knee OA after 6-week intervention (P <.0125). In contrast, the control group showed no change in any of the measured tests. CONCLUSION TMFSE in sitting appears to be an option for exercise in patients with mild to moderate knee OA. This may be an especially attractive option for patients who may have pain with weight-bearing exercises. A longitudinal study with a larger sample size is needed to confirm the potential use of TMFSE for patients with knee OA.
Collapse
|
50
|
Caulo M, Briganti C, Mattei PA, Perfetti B, Ferretti A, Romani GL, Tartaro A, Colosimo C. New morphologic variants of the hand motor cortex as seen with MR imaging in a large study population. AJNR Am J Neuroradiol 2007; 28:1480-5. [PMID: 17846195 PMCID: PMC8134386 DOI: 10.3174/ajnr.a0597] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The hand motor cortex (HMC) has been classically described as having an omega or epsilon shape in axial-plane images obtained with CT and MR imaging. The aim of this study was to use MR imaging and Talairach normalization in a large sample population that was homogeneous for age and handedness to evaluate in a sex model a new classification with 5 morphologic variants of the HMC in the axial plane (omega, medially asymmetric epsilon, epsilon, laterally asymmetric epsilon, and null). MATERIALS AND METHODS Structural brain MR images were obtained from 257 right-handed healthy subjects (143 men and 114 women; mean age, 23.1 +/- 1.1 years) via a Talairach space transformed 3D magnetization-prepared rapid acquisition of gradient echo sequence. The frequencies of the different HMC variants were reported for hemisphere and sex. RESULTS The new variants of the HMC (medially asymmetric epsilon, laterally asymmetric epsilon, and null) were observed in 2.9%, 7.0%, and 1.8% of the hemispheres, respectively. Statistically significant sex differences were observed: The epsilon variant was twice as frequent in men, and an interhemispheric concordance for morphologic variants was observed only for women. CONCLUSION The large study population permitted the description of a new morphologic classification that included 3 new variants of the HMC. This new morphologic classification should facilitate the identification of the precentral gyrus in subsequent studies and in everyday practice.
Collapse
Affiliation(s)
- M Caulo
- Institute Advanced Biomedical Technologies of the Department of Clinical Sciences and Bioimaging, University G. d'Annunzio, Chieti, Italy.
| | | | | | | | | | | | | | | |
Collapse
|