1
|
Collins KC, Clark AB, Pomeroy VM, Kennedy NC. The test-retest reliability of non-navigated transcranial magnetic stimulation (TMS) measures of corticospinal pathway excitability early after stroke. Disabil Rehabil 2024:1-8. [PMID: 38634228 DOI: 10.1080/09638288.2024.2337107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 03/24/2024] [Indexed: 04/19/2024]
Abstract
PURPOSE Motor evoked potential (MEP) characteristics are potential biomarkers of whether rehabilitation interventions drive motor recovery after stroke. The test-retest reliability of Transcranial Magnetic Stimulation (TMS) measurements in sub-acute stroke remains unclear. This study aims to determine the test-retest reliability of upper limb MEP measures elicited by non-neuronavigated transcranial magnetic stimulation in sub-acute-stroke. METHODS In two identical data collection sessions, 1-3 days apart, TMS measures assessed: motor threshold (MT), amplitude, latency (MEP-L), silent period (SP), recruitment curve slope in the biceps brachii (BB), extensor carpi radialis (ECR), and abductor pollicis brevis (APB) muscles of paretic and non-paretic upper limbs. Test-retest reliability was calculated using the intra-class correlation coefficient (ICC) and 95% confidence intervals (CI). Acceptable reliability was set at a lower 95% CI of 0.70 or above. The limits of agreement (LOA) and smallest detectable change (SDC) were calculated. RESULTS 30 participants with sub-acute stroke were included (av 36 days post stroke) reliability was variable between poor to good for the different MEP characteristics. The SDC values differed across muscles and MEP characteristics in both paretic and less paretic limbs. CONCLUSIONS The present findings indicate there is limited evidence for acceptable test-retest reliability of non-navigated TMS outcomes when using the appropriate 95% CI for ICC, SDC and LOA values. CLINICAL TRIAL REGISTRATION Current Controlled Trials: ISCRT 19090862, http://www.controlled-trials.com.
Collapse
Affiliation(s)
- Kathryn C Collins
- Faculty of Health and Social Sciences, Bournemouth University, Bournemouth, UK
| | - Allan B Clark
- Norwich Medical School, University of East Anglia, Norwich, UK
| | - Valerie M Pomeroy
- Acquired Brain Injury Rehabilitation Alliance, School of Health Sciences, University of East Anglia, Norwich, UK
- National Institute of Health Research Brain Injury MedTech Cooperative, Cambridge, UK
| | | |
Collapse
|
2
|
Eibl T, Schrey M, Liebert A, Ritter L, Lange R, Steiner HH, Schebesch KM. Influence of clinical and tumor-specific factors on the resting motor threshold in navigated transcranial magnetic stimulation. Neurophysiol Clin 2023; 53:102920. [PMID: 37944292 DOI: 10.1016/j.neucli.2023.102920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/27/2023] [Accepted: 10/28/2023] [Indexed: 11/12/2023] Open
Abstract
OBJECTIVE Preoperative non-invasive mapping of motor function with navigated transcranial magnetic stimulation (nTMS) has become a widely used diagnostic procedure. Determination of the patient-individual resting motor threshold (rMT) is of great importance to achieve reliable results when conducting nTMS motor mapping. Factors which contribute to differences in rMT of brain tumor patients have not been fully investigated. METHODS We included adult patients with all types of de novo and recurrent intracranial lesions, suspicious for intra-axial brain tumors. The outcome measure was the rMT of the upper extremity, defined as the stimulation intensity eliciting motor evoked potentials with amplitudes greater than 50µV in 50 % of applied stimulations. RESULTS Eighty nTMS examinations in 75 patients (37.5 % female) aged 57.9 ± 14.9 years were evaluated. In non-parametric testing, rMT values were higher in patients with upper extremity paresis (p = 0.024) and lower in patients with high grade gliomas (HGG) (p = 0.001). rMT inversely correlated with patient age (rs=-0.28, p = 0.013) and edema volume (rs=-0.28, p = 0.012) In regression analysis, infiltration of the precentral gyrus (p<0.001) increased rMT values. Values of rMT were reduced in high grade gliomas (p<0.001), in patients taking Levetiracetam (p = 0.019) and if perilesional edema infiltrated motor eloquent brain (p<0.001). Subgroup analyses of glioma patients revealed similar results. Values of rMT did not differ between hand and forearm muscles. CONCLUSION Most factors confounding rMT in our study were specific to the lesion. These factors contributed to the variability in cortical excitability and must be considered in clinical work with nTMS to achieve reliable results with nTMS motor mapping.
Collapse
Affiliation(s)
- Thomas Eibl
- Department of Neurosurgery, Paracelsus Medical University Nuremberg, Germany.
| | - Michael Schrey
- Department of Neurosurgery, Paracelsus Medical University Nuremberg, Germany
| | - Adrian Liebert
- Department of Neurosurgery, Paracelsus Medical University Nuremberg, Germany
| | - Leonard Ritter
- Department of Neurosurgery, Paracelsus Medical University Nuremberg, Germany
| | - Rüdiger Lange
- Department of Neurology, Paracelsus Medical University Nuremberg, Germany
| | | | | |
Collapse
|
3
|
Assessing the feasibility of mapping the tibialis anterior muscle with navigated transcranial magnetic stimulation in neuro-oncologic patients. Sci Rep 2022; 12:18719. [PMID: 36333400 PMCID: PMC9636142 DOI: 10.1038/s41598-022-23444-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
Mapping the lower extremity with navigated transcranial magnetic stimulation (nTMS) still remains challenging for the investigator. Clinical factors influencing leg mapping with nTMS have not been fully investigated yet. The aim of the study was to identify factors which influence the possibility of eliciting motor evoked potentials (MEPs) from the tibialis anterior muscle (TA). Patient records, imaging, nTMS examinations and tractography were retrospectively evaluated. 48 nTMS examinations were performed in 46 brain tumor patients. Reproducible MEPs were recorded in 20 patients (41.67%). Younger age (p = 0.044) and absence of perifocal edema (p = 0.035, Cramer's V = 0.34, OR = 0.22, 95% CI = 0.06-0.81) facilitated mapping the TA muscle. Leg motor deficit (p = 0.49, Cramer's V = 0.12, OR = 0.53, 95%CI = 0.12-2.36), tumor entity (p = 0.36, Cramer's V = 0.22), tumor location (p = 0.52, Cramer's V = 0.26) and stimulation intensity (p = 0.158) were no significant factors. The distance between the tumor and the pyramidal tract was higher (p = 0.005) in patients with successful mapping of the TA. The possibility to stimulate the leg motor area was associated with no postoperative aggravation of motor deficits in general (p = 0.005, Cramer's V = 0.45, OR = 0.63, 95%CI = 0.46-0.85) but could not serve as a specific predictor of postoperative lower extremity function. In conclusion, successful mapping of the TA muscle for neurosurgical planning is influenced by young patient age, absence of edema and greater distance to the CST, whereas tumor entity and stimulation intensity were non-significant.
Collapse
|
4
|
Sondergaard RE, Martino D, Kiss ZHT, Condliffe EG. TMS Motor Mapping Methodology and Reliability: A Structured Review. Front Neurosci 2021; 15:709368. [PMID: 34489629 PMCID: PMC8417420 DOI: 10.3389/fnins.2021.709368] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 07/13/2021] [Indexed: 11/29/2022] Open
Abstract
Motor cortical representation can be probed non-invasively using a transcranial magnetic stimulation (TMS) technique known as motor mapping. The mapping technique can influence features of the maps because of several controllable elements. Here we review the literature on six key motor mapping parameters, as well as their influence on outcome measures and discuss factors impacting their selection. 132 of 1,587 distinct records were examined in detail and synthesized to form the basis of our review. A summary of mapping parameters, their impact on outcome measures and feasibility considerations are reported to support the design and interpretation of TMS mapping studies.
Collapse
Affiliation(s)
- Rachel E. Sondergaard
- Department of Clinical Neuroscience, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Davide Martino
- Department of Clinical Neuroscience, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Zelma H. T. Kiss
- Department of Clinical Neuroscience, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Department of Psychiatry, University of Calgary, Calgary, AB, Canada
| | - Elizabeth G. Condliffe
- Department of Clinical Neuroscience, University of Calgary, Calgary, AB, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
- Department of Pediatrics, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
5
|
Nazarova M, Novikov P, Ivanina E, Kozlova K, Dobrynina L, Nikulin VV. Mapping of multiple muscles with transcranial magnetic stimulation: absolute and relative test-retest reliability. Hum Brain Mapp 2021; 42:2508-2528. [PMID: 33682975 PMCID: PMC8090785 DOI: 10.1002/hbm.25383] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 12/13/2022] Open
Abstract
The spatial accuracy of transcranial magnetic stimulation (TMS) may be as small as a few millimeters. Despite such great potential, navigated TMS (nTMS) mapping is still underused for the assessment of motor plasticity, particularly in clinical settings. Here, we investigate the within-limb somatotopy gradient as well as absolute and relative reliability of three hand muscle cortical representations (MCRs) using a comprehensive grid-based sulcus-informed nTMS motor mapping. We enrolled 22 young healthy male volunteers. Two nTMS mapping sessions were separated by 5-10 days. Motor evoked potentials were obtained from abductor pollicis brevis (APB), abductor digiti minimi, and extensor digitorum communis. In addition to individual MRI-based analysis, we studied normalized MNI MCRs. For the reliability assessment, we calculated intraclass correlation and the smallest detectable change. Our results revealed a somatotopy gradient reflected by APB MCR having the most lateral location. Reliability analysis showed that the commonly used metrics of MCRs, such as areas, volumes, centers of gravity (COGs), and hotspots had a high relative and low absolute reliability for all three muscles. For within-limb TMS somatotopy, the most common metrics such as the shifts between MCR COGs and hotspots had poor relative reliability. However, overlaps between different muscle MCRs were highly reliable. We, thus, provide novel evidence that inter-muscle MCR interaction can be reliably traced using MCR overlaps while shifts between the COGs and hotspots of different MCRs are not suitable for this purpose. Our results have implications for the interpretation of nTMS motor mapping results in healthy subjects and patients with neurological conditions.
Collapse
Affiliation(s)
- Maria Nazarova
- Center for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of EconomicsMoscowRussian Federation
- Federal State Budgetary Institution «Federal center of brain research and neurotechnologies» of the Federal Medical Biological AgencyMoscowRussian Federation
| | - Pavel Novikov
- Center for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of EconomicsMoscowRussian Federation
| | - Ekaterina Ivanina
- Center for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of EconomicsMoscowRussian Federation
| | - Ksenia Kozlova
- Center for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of EconomicsMoscowRussian Federation
| | | | - Vadim V. Nikulin
- Center for Cognition and Decision Making, Institute for Cognitive Neuroscience, National Research University Higher School of EconomicsMoscowRussian Federation
- Department of NeurologyMax Planck Institute for Human Cognitive and Brain SciencesLeipzigGermany
| |
Collapse
|
6
|
Haddad AF, Young JS, Berger MS, Tarapore PE. Preoperative Applications of Navigated Transcranial Magnetic Stimulation. Front Neurol 2021; 11:628903. [PMID: 33551983 PMCID: PMC7862711 DOI: 10.3389/fneur.2020.628903] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 12/29/2020] [Indexed: 12/18/2022] Open
Abstract
Preoperative mapping of cortical structures prior to neurosurgical intervention can provide a roadmap of the brain with which neurosurgeons can navigate critical cortical structures. In patients undergoing surgery for brain tumors, preoperative mapping allows for improved operative planning, patient risk stratification, and personalized preoperative patient counseling. Navigated transcranial magnetic stimulation (nTMS) is one modality that allows for highly accurate, image-guided, non-invasive stimulation of the brain, thus allowing for differentiation between eloquent and non-eloquent cortical regions. Motor mapping is the best validated application of nTMS, yielding reliable maps with an accuracy similar to intraoperative cortical mapping. Language mapping is also commonly performed, although nTMS language maps are not as highly concordant with direct intraoperative cortical stimulation maps as nTMS motor maps. Additionally, nTMS has been used to localize cortical regions involved in other functions such as facial recognition, calculation, higher-order motor processing, and visuospatial orientation. In this review, we evaluate the growing literature on the applications of nTMS in the preoperative setting. First, we analyze the evidence in support of the most common clinical applications. Then we identify usages that show promise but require further validation. We also discuss developing nTMS techniques that are still in the experimental stage, such as the use of nTMS to enhance postoperative recovery. Finally, we highlight practical considerations when utilizing nTMS and, importantly, its safety profile in neurosurgical patients. In so doing, we aim to provide a comprehensive review of the role of nTMS in the neurosurgical management of a patient with a brain tumor.
Collapse
Affiliation(s)
- Alexander F Haddad
- School of Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Jacob S Young
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Mitchel S Berger
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States
| | - Phiroz E Tarapore
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States
| |
Collapse
|
7
|
Short-Interval Intracortical Facilitation Improves Efficacy in nTMS Motor Mapping of Lower Extremity Muscle Representations in Patients with Supra-Tentorial Brain Tumors. Cancers (Basel) 2020; 12:cancers12113233. [PMID: 33147827 PMCID: PMC7692031 DOI: 10.3390/cancers12113233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/27/2020] [Accepted: 10/29/2020] [Indexed: 02/06/2023] Open
Abstract
Navigated transcranial magnetic stimulation (nTMS) is increasingly used for mapping of motor function prior to surgery in patients harboring motor-eloquent brain lesions. To date, single-pulse nTMS (sp-nTMS) has been predominantly used for this purpose, but novel paired-pulse nTMS (pp-nTMS) with biphasic pulse application has been made available recently. The purpose of this study was to systematically evaluate pp-nTMS with biphasic pulses in comparison to conventionally used sp-nTMS for preoperative motor mapping of lower extremity (lE) muscle representations. Thirty-nine patients (mean age: 56.3 ± 13.5 years, 69.2% males) harboring motor-eloquent brain lesions of different entity underwent motor mapping of lE muscle representations in lesion-affected hemispheres and nTMS-based tractography of the corticospinal tract (CST) using data from sp-nTMS and pp-nTMS with biphasic pulses, respectively. Compared to sp-nTMS, pp-nTMS enabled motor mapping with lower stimulation intensities (61.8 ± 13.8% versus 50.7 ± 11.6% of maximum stimulator output, p < 0.0001), and it provided reliable motor maps even in the most demanding cases where sp-nTMS failed (pp-nTMS was able to provide a motor map in five patients in whom sp-nTMS did not provide any motor-positive points, and pp-nTMS was the only modality to provide a motor map in one patient who also did not show motor-positive points during intraoperative stimulation). Fiber volumes of the tracked CST were slightly higher when motor maps of pp-nTMS were used, and CST tracking using pp-nTMS data was also possible in the five patients in whom sp-nTMS failed. In conclusion, application of pp-nTMS with biphasic pulses enables preoperative motor mapping of lE muscle representations even in the most challenging patients in whom the motor system is at high risk due to lesion location or resection.
Collapse
|
8
|
Accuracy of Estimating the Area of Cortical Muscle Representations from TMS Mapping Data Using Voronoi Diagrams. Brain Topogr 2019; 32:859-872. [PMID: 31073791 DOI: 10.1007/s10548-019-00714-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 05/02/2019] [Indexed: 12/13/2022]
Abstract
Motor evoked potentials (MEPs) caused by transcranial magnetic stimulation (TMS) provide a possibility of noninvasively mapping cortical muscle representations for clinical and research purposes. The interpretation of such results is complicated by the high variability in MEPs and the lack of a standard optimal mapping protocol. Comparing protocols requires the determination of the accuracy of estimated representation parameters (such as the area), which is problematic without ground truth data. We addressed this problem and obtained two main results: (1) the development of a bootstrapping-based approach for estimating the within-session variability and bias of representation parameters and (2) estimations of the area and amplitude-weighted area accuracies for motor representations using this approach. The method consists in the simulation of TMS mapping results by subsampling MEPs from a single map with a large number of stimuli. We studied the extensor digitorum communis (EDC) and flexor digitorum superficialis (FDS) muscle maps of 15 healthy subjects processed using Voronoi diagrams. We calculated the (decreasing) dependency of the errors in the area and weighted area on the number of stimuli. This result can be used to choose a number of stimuli sufficient for studying the effects of a given size (e.g., the protocol with 150 stimuli leads to relative errors of 7% for the area and 11% for the weighted area in 90% of the maps). The approach is applicable to other parameters (e.g., the center of gravity) and other map processing methods, such as spline interpolation.
Collapse
|
9
|
Sinitsyn DO, Chernyavskiy AY, Poydasheva AG, Bakulin IS, Suponeva NA, Piradov MA. Optimization of the Navigated TMS Mapping Algorithm for Accurate Estimation of Cortical Muscle Representation Characteristics. Brain Sci 2019; 9:brainsci9040088. [PMID: 31010190 PMCID: PMC6523347 DOI: 10.3390/brainsci9040088] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 12/13/2022] Open
Abstract
Navigated transcranial magnetic stimulation (nTMS) mapping of cortical muscle representations allows noninvasive assessment of the state of a healthy or diseased motor system, and monitoring changes over time. These applications are hampered by the heterogeneity of existing mapping algorithms and the lack of detailed information about their accuracy. We aimed to find an optimal motor evoked potential (MEP) sampling scheme in the grid-based mapping algorithm in terms of the accuracy of muscle representation parameters. The abductor pollicis brevis (APB) muscles of eight healthy subjects were mapped three times on consecutive days using a seven-by-seven grid with ten stimuli per cell. The effect of the MEP variability on the parameter accuracy was assessed using bootstrapping. The accuracy of representation parameters increased with the number of stimuli without saturation up to at least ten stimuli per cell. The detailed sampling showed that the between-session representation area changes in the absence of interventions were significantly larger than the within-session fluctuations and thus could not be explained solely by the trial-to-trial variability of MEPs. The results demonstrate that the number of stimuli has no universally optimal value and must be chosen by balancing the accuracy requirements with the mapping time constraints in a given problem.
Collapse
Affiliation(s)
- Dmitry O Sinitsyn
- Department of Neurorehabilitation and Physiotherapy, Research Center of Neurology, 125367 Moscow, Russia.
| | - Andrey Yu Chernyavskiy
- Department of Neurorehabilitation and Physiotherapy, Research Center of Neurology, 125367 Moscow, Russia.
- Quantum Computer Physics Laboratory, Valiev Institute of Physics and Technology of Russian Academy of Sciences, 117218 Moscow, Russia.
| | - Alexandra G Poydasheva
- Department of Neurorehabilitation and Physiotherapy, Research Center of Neurology, 125367 Moscow, Russia.
| | - Ilya S Bakulin
- Department of Neurorehabilitation and Physiotherapy, Research Center of Neurology, 125367 Moscow, Russia.
| | - Natalia A Suponeva
- Department of Neurorehabilitation and Physiotherapy, Research Center of Neurology, 125367 Moscow, Russia.
| | - Michael A Piradov
- Department of Neurorehabilitation and Physiotherapy, Research Center of Neurology, 125367 Moscow, Russia.
| |
Collapse
|
10
|
Charalambous CC, Liang JN, Kautz SA, George MS, Bowden MG. Bilateral Assessment of the Corticospinal Pathways of the Ankle Muscles Using Navigated Transcranial Magnetic Stimulation. J Vis Exp 2019. [PMID: 30855569 DOI: 10.3791/58944] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Distal leg muscles receive neural input from motor cortical areas via the corticospinal tract, which is one of the main motor descending pathway in humans and can be assessed using transcranial magnetic stimulation (TMS). Given the role of distal leg muscles in upright postural and dynamic tasks, such as walking, a growing research interest in the assessment and modulation of the corticospinal tracts relative to the function of these muscles has emerged in the last decade. However, methodological parameters used in previous work have varied across studies making the interpretation of results from cross-sectional and longitudinal studies less robust. Therefore, use of a standardized TMS protocol specific to the assessment of leg muscles' corticomotor response (CMR) will allow for direct comparison of results across studies and cohorts. The objective of this paper is to present a protocol that provides the flexibility to simultaneously assess the bilateral CMR of two main ankle antagonistic muscles, the tibialis anterior and soleus, using single pulse TMS with a neuronavigation system. The present protocol is applicable while the examined muscle is either fully relaxed or isometrically contracted at a defined percentage of maximum isometric voluntary contraction. Using each subject's structural MRI with the neuronavigation system ensures accurate and precise positioning of the coil over the leg cortical representations during assessment. Given the inconsistency in CMR derived measures, this protocol also describes a standardized calculation of these measures using automated algorithms. Though this protocol is not conducted during upright postural or dynamic tasks, it can be used to assess bilaterally any pair of leg muscles, either antagonistic or synergistic, in both neurologically intact and impaired subjects.
Collapse
Affiliation(s)
- Charalambos C Charalambous
- Department of Neurology, New York University School of Medicine; Department of Health Sciences and Research, Medical University of South Carolina;
| | - Jing Nong Liang
- Department of Physical Therapy, University of Nevada Las Vegas; Department of Health Professions, Medical University of South Carolina
| | - Steve A Kautz
- Department of Health Sciences and Research, Medical University of South Carolina; Ralph H. Johnson VA Medical Center
| | - Mark S George
- Ralph H. Johnson VA Medical Center; Department of Psychiatry, Medical University of South Carolina
| | - Mark G Bowden
- Department of Health Sciences and Research, Medical University of South Carolina; Ralph H. Johnson VA Medical Center; Division of Physical Therapy, Medical University of South Carolina
| |
Collapse
|
11
|
Rosso C, Lamy JC. Does Resting Motor Threshold Predict Motor Hand Recovery After Stroke? Front Neurol 2018; 9:1020. [PMID: 30555404 PMCID: PMC6281982 DOI: 10.3389/fneur.2018.01020] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 11/12/2018] [Indexed: 12/15/2022] Open
Abstract
Background: Resting Motor threshold (rMT) is one of the measurement obtained by Transcranial Magnetic Stimulation (TMS) that reflects corticospinal excitability. As a functional marker of the corticospinal pathway, the question arises whether rMT is a suitable biomarker for predicting post-stroke upper limb function. To that aim, we conducted a systematic review of relevant studies that investigated the clinical significance of rMT in stroke survivors by using correlations between upper limb motor scores and rMT. Methods: Studies that reported correlations between upper limb motor function and rMT as a measure of corticospinal excitability in distal arm muscle were identified via a literature search in stroke patients. Two authors extracted the data using a home-made specific form. Subgroup analyses were carried out with patients classified with respect to time post-stroke onset (early vs. chronic stage) and stroke location (cortical, subcortical, or cortico-subcortical). Methodological quality of the study was also evaluated by a published checklist. Results: Eighteen studies with 22 groups (n = 508 stroke patients) were included in this systematic review. Mean methodological quality score was 14.75/24. rMT was often correlated with motor function or hand dexterity (n = 15/22, 68%), explaining on average 31% of the variance of the motor score. Moreover, the results did not seem impacted if patients were examined at the early or chronic stages of stroke. Two findings could not be properly interpreted: (i) the fact that the rMT is an independent predictor of motor function as several confounding factors are well-established, and, (ii) whether the stroke location impacts this prediction. Conclusion: Most of the studies found a correlation between rMT and upper limb motor function after stroke. However, it is still unclear if rMT is an independent predictor of upper limb motor function when taking into account for age, time post stroke onset and level of corticospinal tract damage as confounding factors. Clear-cut conclusions could not be drawn at that time but our results suggest that rMT could be a suitable candidate although future investigations are needed. Systematic Review Registration Number: (https://www.crd.york.ac.uk/prospero/): ID 114317.
Collapse
Affiliation(s)
- Charlotte Rosso
- Institut du Cerveau et de la Moelle épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France.,APHP, Urgences Cérébro-Vasculaires, Hôpital Pitié-Salpêtrière, Paris, France
| | - Jean-Charles Lamy
- Institut du Cerveau et de la Moelle épinière, ICM, Inserm U 1127, CNRS UMR 7225, Sorbonne Université, Paris, France
| |
Collapse
|
12
|
Gibson BC, Sanguinetti JL, Badran BW, Yu AB, Klein EP, Abbott CC, Hansberger JT, Clark VP. Increased Excitability Induced in the Primary Motor Cortex by Transcranial Ultrasound Stimulation. Front Neurol 2018; 9:1007. [PMID: 30546342 PMCID: PMC6280333 DOI: 10.3389/fneur.2018.01007] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/07/2018] [Indexed: 12/29/2022] Open
Abstract
Background: Transcranial Ultrasound Stimulation (tUS) is an emerging technique that uses ultrasonic waves to noninvasively modulate brain activity. As with other forms of non-invasive brain stimulation (NIBS), tUS may be useful for altering cortical excitability and neuroplasticity for a variety of research and clinical applications. The effects of tUS on cortical excitability are still unclear, and further complications arise from the wide parameter space offered by various types of devices, transducer arrangements, and stimulation protocols. Diagnostic ultrasound imaging devices are safe, commonly available systems that may be useful for tUS. However, the feasibility of modifying brain activity with diagnostic tUS is currently unknown. Objective: We aimed to examine the effects of a commercial diagnostic tUS device using an imaging protocol on cortical excitability. We hypothesized that imaging tUS applied to motor cortex could induce changes in cortical excitability as measured using a transcranial magnetic stimulation (TMS) motor evoked potential (MEP) paradigm. Methods: Forty-three subjects were assigned to receive either verum (n = 21) or sham (n = 22) diagnostic tUS in a single-blind design. Baseline motor cortex excitability was measured using MEPs elicited by TMS. Diagnostic tUS was subsequently administered to the same cortical area for 2 min, immediately followed by repeated post-stimulation MEPs recorded up to 16 min post-stimulation. Results: Verum tUS increased excitability in the motor cortex (from baseline) by 33.7% immediately following tUS (p = 0.009), and 32.4% (p = 0.047) 6 min later, with excitability no longer significantly different from baseline by 11 min post-stimulation. By contrast, subjects receiving sham tUS showed no significant changes in MEP amplitude. Conclusion: These findings demonstrate that tUS delivered via a commercially available diagnostic imaging ultrasound system transiently increases excitability in the motor cortex as measured by MEPs. Diagnostic tUS devices are currently used for internal imaging in many health care settings, and the present results suggest that these same devices may also offer a promising tool for noninvasively modulating activity in the central nervous system. Further studies exploring the use of diagnostic imaging devices for neuromodulation are warranted.
Collapse
Affiliation(s)
- Benjamin C. Gibson
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Joseph L. Sanguinetti
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
- U.S. Army Research Laboratory, Aberdeen Proving Ground, MD, United States
| | - Bashar W. Badran
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
- U.S. Army Research Laboratory, Aberdeen Proving Ground, MD, United States
- Department of Biomedical Engineering, The City College of New York, New York, NY, United States
- Brain Stimulation Laboratory, Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Alfred B. Yu
- U.S. Army Research Laboratory, Aberdeen Proving Ground, MD, United States
| | - Evan P. Klein
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Christopher C. Abbott
- Department of Psychiatry, University of New Mexico School of Medicine, Albuquerque, NM, United States
| | | | - Vincent P. Clark
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
- Department of Neurosciences, University of New Mexico School of Medicine, Albuquerque, NM, United States
- The Mind Research Network & LBERI, Albuquerque, NM, United States
| |
Collapse
|
13
|
Charalambous CC, Dean JC, Adkins DL, Hanlon CA, Bowden MG. Characterizing the corticomotor connectivity of the bilateral ankle muscles during rest and isometric contraction in healthy adults. J Electromyogr Kinesiol 2018; 41:9-18. [PMID: 29715530 DOI: 10.1016/j.jelekin.2018.04.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 04/20/2018] [Accepted: 04/23/2018] [Indexed: 01/19/2023] Open
Abstract
The investigation of the corticomotor connectivity (CMC) to leg muscles is an emerging research area, and establishing reliability of measures is critical. This study examined the measurement reliability and the differences between bilateral soleus (SOL) and tibialis anterior (TA) CMC in 21 neurologically intact adults. Using single pulse transcranial magnetic stimulation (TMS), each muscle's CMC was assessed twice (7 ± 2 days apart) during rest and active conditions. CMC was quantified using a standardized battery of eight measures (4/condition): motor threshold during resting (RMT), motor evoked potential amplitude and latency (raw and normalized to height) in both conditions, contralateral silent period (CSP) during active. Using two reliability metrics (intraclass correlation coefficient and coefficient of variation of method error; good reliability: ≥0.75 and ≤15, respectively) and repeated-measures ANOVA, we investigated the reliability and Muscle X Body Side interaction. For both muscles, RMT, resting raw and normalized latencies, and active raw latency demonstrated good reliability, while CSP had good reliability only for TA. Amplitude did not demonstrate good reliability for both muscles. SOL CMC was significantly different from TA CMC for all measures but CSP; body side had no significant effect. Therefore, only certain measures may reliably quantify SOL and TA CMC while different CMC (except CSP) between SOL and TA suggests dissimilar corticospinal drive to each muscle regardless of the side.
Collapse
Affiliation(s)
- Charalambos C Charalambous
- Department of Neurology, New York University School of Medicine, New York, NY, USA; Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA.
| | - Jesse C Dean
- Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Charleston, SC, USA; Division of Physical Therapy, Medical University of South Carolina, Charleston, SC, USA
| | - DeAnna L Adkins
- Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA
| | - Colleen A Hanlon
- Ralph H. Johnson VA Medical Center, Charleston, SC, USA; Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA; Center for Biomedical Imaging, Medical University of South Carolina, Charleston, SC, USA; Department of Psychiatry, Medical University of South Carolina, Charleston, SC, USA
| | - Mark G Bowden
- Department of Health Sciences and Research, Medical University of South Carolina, Charleston, SC, USA; Ralph H. Johnson VA Medical Center, Charleston, SC, USA; Division of Physical Therapy, Medical University of South Carolina, Charleston, SC, USA
| |
Collapse
|
14
|
Rosenstock T, Giampiccolo D, Schneider H, Runge SJ, Bährend I, Vajkoczy P, Picht T. Specific DTI seeding and diffusivity-analysis improve the quality and prognostic value of TMS-based deterministic DTI of the pyramidal tract. NEUROIMAGE-CLINICAL 2017; 16:276-285. [PMID: 28840099 PMCID: PMC5560117 DOI: 10.1016/j.nicl.2017.08.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 06/22/2017] [Accepted: 08/11/2017] [Indexed: 12/17/2022]
Abstract
Object Navigated transcranial magnetic stimulation (nTMS) combined with diffusion tensor imaging (DTI) is used preoperatively in patients with eloquent-located brain lesions and allows analyzing non-invasively the spatial relationship between the tumor and functional areas (e.g. the motor cortex and the corticospinal tract [CST]). In this study, we examined the diffusion parameters FA (fractional anisotropy) and ADC (apparent diffusion coefficient) within the CST in different locations and analyzed their interrater reliability and usefulness for predicting the patients' motor outcome with a precise approach of specific region of interest (ROI) seeding based on the color-coded FA-map. Methods Prospectively collected data of 30 patients undergoing bihemispheric nTMS mapping followed by nTMS-based DTI fiber tracking prior to surgery of motor eloquent high-grade gliomas were analyzed by 2 experienced and 1 unexperienced examiner. The following data were scrutinized for both hemispheres after tractography based on nTMS-motor positive cortical seeds and a 2nd region of interest in one layer of the caudal pons defined by the color-coded FA-map: the pre- and postoperative motor status (day of discharge und 3 months), the closest distance between the tracts and the tumor (TTD), the fractional anisotropy (FA) and the apparent diffusion coefficient (ADC). The latter as an average within the CST as well as specific values in different locations (peritumoral, mesencephal, pontine). Results Lower average FA-values within the affected CST as well as higher average ADC-values are significantly associated with deteriorated postoperative motor function (p = 0.006 and p = 0.026 respectively). Segmental analysis within the CST revealed that the diffusion parameters are especially disturbed on a peritumoral level and that the degree of their impairment correlates with motor deficits (FA p = 0.065, ADC p = 0.007). No significant segmental variation was seen in the healthy hemisphere. The interrater reliability showed perfect agreement for almost all analyzed parameters. Conclusions Adding diffusion weighted imaging derived information on the structural integrity of the nTMS-based tractography results improves the predictive power for postoperative motor outcome. Utilizing a second subcortical ROI which is specifically seeded based on the color-coded FA map increases the tracking quality of the CST independently of the examiner's experience. Further prospective studies are needed to validate the nTMS-based prediction of the patient's outcome. ROI seeding based on nTMS-data and FA-maps improves DTI tractography of the CST. Perfect interrater reliability for DTI tractography of the CST was observed. The pattern of diffusivity disturbance predicts the postoperative motor outcome.
Collapse
Affiliation(s)
- Tizian Rosenstock
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, 10117 Berlin, Germany
| | - Davide Giampiccolo
- Institute of Neurosurgery, University Hospital, Piazzale Stefani 1, 37100 Verona, Italy
| | - Heike Schneider
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, 10117 Berlin, Germany
| | - Sophia Jutta Runge
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, 10117 Berlin, Germany
| | - Ina Bährend
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, 10117 Berlin, Germany
| | - Peter Vajkoczy
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, 10117 Berlin, Germany
| | - Thomas Picht
- Department of Neurosurgery, Charité University Medicine, Charitéplatz 1, 10117 Berlin, Germany
| |
Collapse
|
15
|
Washabaugh EP, Krishnan C. A low-cost system for coil tracking during transcranial magnetic stimulation. Restor Neurol Neurosci 2016; 34:337-46. [PMID: 26923620 DOI: 10.3233/rnn-150609] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE Accurate coil placement over a target area is critical during transcranial magnetic stimulation (TMS), as small deviations can alter testing outcomes. Accordingly, frameless stereotaxic systems (FSS) are recommended for reliable coil placement during TMS applications. However, FSS is not practical due to the cost associated with procuring such systems. Therefore, the purpose of this study was to develop a low-cost TMS coil tracking approach using simple webcams and an image processing algorithm in LabVIEW Vision Assistant. METHODS A system was created using two webcams, retroreflective markers, and computer stereovision, for tracking the TMS coil over a target area. Accuracy of the system was validated in both the global and local reference frames, while repeatability was measured within- and between-days for placement of the TMS coil over the target area relative to the head. The feasibility of our system was also verified by collecting motor evoked potentials (MEPs) of first dorsal interosseous muscle from human subjects. RESULTS The results of this study indicated that the system was highly accurate and repeatable, and could track the coil position with <5 mm error and orientation <1.1° error from the target. We also observed larger and more consistent MEPs when stimulating the brain using feedback from the coil tracking system than when the examiner attempted to stimulate without any feedback. CONCLUSION The findings suggest that webcam-based coil tracking is a feasible low-cost solution to track coil positions during TMS procedures.
Collapse
Affiliation(s)
- Edward P Washabaugh
- Department of Physical Medicine and Rehabilitation, University of Michigan Medical School, Ann Arbor, MI, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Chandramouli Krishnan
- Department of Physical Medicine and Rehabilitation, University of Michigan Medical School, Ann Arbor, MI, USA.,School of Kinesiology, University of Michigan, Ann Arbor, MI, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
16
|
Weiss Lucas C, Tursunova I, Neuschmelting V, Nettekoven C, Oros-Peusquens AM, Stoffels G, Faymonville AM, Jon SN, Langen KJ, Lockau H, Goldbrunner R, Grefkes C. Functional MRI vs. navigated TMS to optimize M1 seed volume delineation for DTI tractography. A prospective study in patients with brain tumours adjacent to the corticospinal tract. NEUROIMAGE-CLINICAL 2016; 13:297-309. [PMID: 28050345 PMCID: PMC5192048 DOI: 10.1016/j.nicl.2016.11.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 11/18/2016] [Accepted: 11/19/2016] [Indexed: 01/01/2023]
Abstract
BACKGROUND DTI-based tractography is an increasingly important tool for planning brain surgery in patients suffering from brain tumours. However, there is an ongoing debate which tracking approaches yield the most valid results. Especially the use of functional localizer data such as navigated transcranial magnetic stimulation (nTMS) or functional magnetic resonance imaging (fMRI) seem to improve fibre tracking data in conditions where anatomical landmarks are less informative due to tumour-induced distortions of the gyral anatomy. We here compared which of the two localizer techniques yields more plausible results with respect to mapping different functional portions of the corticospinal tract (CST) in brain tumour patients. METHODS The CSTs of 18 patients with intracranial tumours in the vicinity of the primary motor area (M1) were investigated by means of deterministic DTI. The core zone of the tumour-adjacent hand, foot and/or tongue M1 representation served as cortical regions of interest (ROIs). M1 core zones were defined by both the nTMS hot-spots and the fMRI local activation maxima. In addition, for all patients, a subcortical ROI at the level of the inferior anterior pons was implemented into the tracking algorithm in order to improve the anatomical specificity of CST reconstructions. As intra-individual control, we additionally tracked the CST of the hand motor region of the unaffected, i.e., non-lesional hemisphere, again comparing fMRI and nTMS M1 seeds. The plausibility of the fMRI-ROI- vs. nTMS-ROI-based fibre trajectories was assessed by a-priori defined anatomical criteria. Moreover, the anatomical relationship of different fibre courses was compared regarding their distribution in the anterior-posterior direction as well as their location within the posterior limb of the internal capsule (PLIC). RESULTS Overall, higher plausibility rates were observed for the use of nTMS- as compared to fMRI-defined cortical ROIs (p < 0.05) in tumour vicinity. On the non-lesional hemisphere, however, equally good plausibility rates (100%) were observed for both localizer techniques. fMRI-originated fibres generally followed a more posterior course relative to the nTMS-based tracts (p < 0.01) in both the lesional and non-lesional hemisphere. CONCLUSION NTMS achieved better tracking results than fMRI in conditions when the cortical tract origin (M1) was located in close vicinity to a brain tumour, probably influencing neurovascular coupling. Hence, especially in situations with altered BOLD signal physiology, nTMS seems to be the method of choice in order to identify seed regions for CST mapping in patients.
Collapse
Key Words
- APB, Abductor pollicis brevis muscle
- BOLD, Blood-oxygenation-level dependent
- CST
- CST, Corticospinal tract
- DCS, Direct cortical stimulation
- DTI, Diffusion tensor imaging
- Deterministic
- EF, Electric field
- EMG, Electromyography
- FA(T), Fractional anisotropy (threshold)
- FACT, Fibre assignment by continuous tracking
- FOV, Field-of-view
- FWE, Family-wise error
- KPS, Karnofsky performance scale
- LT, Lateral tongue muscle, anterior third
- M1, Primary motor cortex
- MEP, Motor-evoked potential
- MFL, Minimal fibre length
- MPRAGE, Magnetization prepared rapid acquisition gradient echo (T1 MR seq.)
- OR, Odd's ratio
- PLIC, Posterior limb of the internal capsule
- PM, Plantar muscle
- Pyramidal tract
- RMT, Resting motor threshold
- ROI
- ROI, Region-of-interest
- SD, Standard deviation
- SE, Standard error
- Somatotopic
- X-sq, X-squared (Pearson's chi-square test)
- dMRI, Diffusion magnetic resonance imaging (i.e., diffusion-weighted imaging, DWI)
- fMRI
- fMRI, Functional magnetic resonance imaging
- nTMS
- nTMS, Neuronavigated transcranial magnetic stimulation
- pxsq, p-value according to Pearson's chi-square test
Collapse
Affiliation(s)
| | - Irada Tursunova
- University of Cologne, Center of Neurosurgery, 50924 Cologne, Germany
| | | | | | | | - Gabriele Stoffels
- Institute of Neuroscience and Medicine, Research Centre Jülich, 52425 Jülich, Germany
| | | | - Shah N Jon
- Institute of Neuroscience and Medicine, Research Centre Jülich, 52425 Jülich, Germany; RWTH Aachen University, University Clinic Aachen, Departments of Nuclear Medicine and Neurology, 52074 Aachen, Germany; Department of Electrical and Computer Systems Engineering, Monash University, Melbourne, Victoria, Australia; Monash Institute of Medical Engineering, Monash University, Melbourne, Victoria, Australia; Monash Biomedical Imaging, School of Psychological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Karl Josef Langen
- Institute of Neuroscience and Medicine, Research Centre Jülich, 52425 Jülich, Germany; RWTH Aachen University, University Clinic Aachen, Departments of Nuclear Medicine and Neurology, 52074 Aachen, Germany
| | - Hannah Lockau
- University of Cologne, Department of Radiology, 50937 Cologne, Germany
| | | | - Christian Grefkes
- Institute of Neuroscience and Medicine, Research Centre Jülich, 52425 Jülich, Germany; University of Cologne, Department of Neurology, 50924 Cologne, Germany
| |
Collapse
|
17
|
Neuromuscular Plasticity: Disentangling Stable and Variable Motor Maps in the Human Sensorimotor Cortex. Neural Plast 2016; 2016:7365609. [PMID: 27610248 PMCID: PMC5004060 DOI: 10.1155/2016/7365609] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/28/2016] [Accepted: 07/19/2016] [Indexed: 02/02/2023] Open
Abstract
Motor maps acquired with transcranial magnetic stimulation (TMS) are evolving as a biomarker for monitoring disease progression or the effects of therapeutic interventions. High test-retest reliability of this technique for long observation periods is therefore required to differentiate daily or weekly fluctuations from stable plastic reorganization of corticospinal connectivity. In this study, a novel projection, interpolation, and coregistration technique, which considers the individual gyral anatomy, was applied in healthy subjects for biweekly acquired TMS motor maps over a period of twelve weeks. The intraclass correlation coefficient revealed long-term reliability of motor maps with relevant interhemispheric differences. The sensorimotor cortex and nonprimary motor areas of the dominant hemisphere showed more extended and more stable corticospinal connectivity. Long-term correlations of the MEP amplitudes at each stimulation site revealed mosaic-like clusters of consistent corticospinal excitability. The resting motor threshold, centre of gravity, and mean MEPs across all TMS sites, as highly reliable cortical map parameters, could be disentangled from more variable parameters such as MEP area and volume. Cortical TMS motor maps provide high test-retest reliability for long-term monitoring when analyzed with refined techniques. They may guide restorative interventions which target dormant corticospinal connectivity for neurorehabilitation.
Collapse
|
18
|
Cassidy JM, Chu H, Chen M, Kimberley TJ, Carey JR. Interhemispheric Inhibition Measurement Reliability in Stroke: A Pilot Study. Neuromodulation 2016; 19:838-847. [PMID: 27333364 DOI: 10.1111/ner.12459] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 04/02/2016] [Accepted: 04/29/2016] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Reliable transcranial magnetic stimulation (TMS) measures for probing corticomotor excitability are important when assessing the physiological effects of noninvasive brain stimulation. The primary objective of this study was to examine test-retest reliability of an interhemispheric inhibition (IHI) index measurement in stroke. MATERIALS AND METHODS Ten subjects with chronic stroke (≥6 months) completed two IHI testing sessions per week for three weeks (six testing sessions total). A single investigator measured IHI in the contra-to-ipsilesional primary motor cortex direction and in the opposite direction using bilateral paired-pulse TMS. Weekly sessions were separated by 24 hours with a 1-week washout period separating testing weeks. To determine if motor-evoked potential (MEP) quantification method affected measurement reliability, IHI indices computed from both MEP amplitude and area responses were found. Reliability was assessed with two-way, mixed intraclass correlation coefficients (ICC(3,k) ). Standard error of measurement and minimal detectable difference statistics were also determined. RESULTS With the exception of the initial testing week, IHI indices measured in the contra-to-ipsilesional hemisphere direction demonstrated moderate to excellent reliability (ICC = 0.725-0.913). Ipsi-to-contralesional IHI indices depicted poor or invalid reliability estimates throughout the three-week testing duration (ICC= -1.153-0.105). The overlap of ICC 95% confidence intervals suggested that IHI indices using MEP amplitude vs. area measures did not differ with respect to reliability. CONCLUSIONS IHI indices demonstrated varying magnitudes of reliability irrespective of MEP quantification method. Several strategies for improving IHI index measurement reliability are discussed.
Collapse
Affiliation(s)
- Jessica M Cassidy
- Department of Physical Medicine and Rehabilitation, Programs in Physical Therapy and Rehabilitation Science, University of Minnesota, Minneapolis, MN, USA
| | - Haitao Chu
- Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, USA
| | - Mo Chen
- Institute for Engineering in Medicine, University of Minnesota, Minneapolis, MN
| | - Teresa J Kimberley
- Department of Physical Medicine and Rehabilitation, Programs in Physical Therapy and Rehabilitation Science, University of Minnesota, Minneapolis, MN, USA
| | - James R Carey
- Department of Physical Medicine and Rehabilitation, Programs in Physical Therapy and Rehabilitation Science, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
19
|
Picht T. Current and potential utility of transcranial magnetic stimulation in the diagnostics before brain tumor surgery. CNS Oncol 2015; 3:299-310. [PMID: 25286041 DOI: 10.2217/cns.14.25] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
This article describes the evolution and state-of-the-art of navigated transcranial magnetic stimulation for evaluation of patients with brain tumors in presumed eloquent location. Alternative noninvasive technologies for functional brain mapping are described and assessed in the context of their usability and clinical needs. In addition to the description of the current validation level and clinical application of navigated transcranial magnetic stimulation for motor and language mapping, the manuscript highlights ongoing research efforts and provides an outlook on upcoming developments in the field of noninvasive brain mapping. Finally, the clinical rationale for presurgical noninvasive brain mapping is discussed in the light of current developments in neurosurgery.
Collapse
|
20
|
van de Ruit M, Perenboom MJL, Grey MJ. TMS brain mapping in less than two minutes. Brain Stimul 2014; 8:231-9. [PMID: 25556004 DOI: 10.1016/j.brs.2014.10.020] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 10/23/2014] [Accepted: 10/23/2014] [Indexed: 10/24/2022] Open
Abstract
BACKGROUND Transcranial magnetic stimulation (TMS) corticospinal excitability maps are a valuable tool to study plasticity in the corticospinal tract. Traditionally, data acquisition for a single map is time consuming, limiting the method's applicability when excitability changes quickly, such as during motor learning, and in clinical investigations where assessment time is a limiting factor. OBJECTIVE To reduce the time needed to create a reliable map by 1) investigating the minimum interstimulus interval (ISI) at which stimuli may be delivered, and 2) investigating the minimum number of stimuli required to create a map. METHOD Frameless stereotaxy was used to monitor coil position as the coil was moved pseudorandomly within a 6 × 6 cm square. Maps were acquired using 1-4 s ISIs in 12 participants. The minimum number of stimuli was determined by randomly extracting data and comparing the resulting map to the original data set. To confirm validity, the pseudorandom walk method was compared against a traditional mapping method. RESULTS Reliable maps could be created with 63 stimuli recorded with a 1 s ISI. Maps created acquiring data using the pseudorandom walk method were not significantly different from maps acquired following the traditional method. CONCLUSIONS To account for inter-participant variability, outliers, coil positioning errors and, most importantly, participant comfort during data acquisition, we recommend creating a map with 80 stimuli and a 1.5 s ISI. This makes it possible to acquire TMS maps in 2 min, making mapping a more feasible tool to study short- and long-term changes in cortical organization.
Collapse
Affiliation(s)
- Mark van de Ruit
- NIHR Surgical Reconstruction and Microbiology Research Centre, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston B15 2TT, UK; MRC-ARUK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston B15 2TT, UK
| | - Matthijs J L Perenboom
- Department of Biomechanical Engineering, Delft University of Technology, Delft, the Netherlands
| | - Michael J Grey
- NIHR Surgical Reconstruction and Microbiology Research Centre, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston B15 2TT, UK; MRC-ARUK Centre for Musculoskeletal Ageing Research, School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Edgbaston B15 2TT, UK; Department of Neuroscience and Pharmacology, Panum Institute, University of Copenhagen, Copenhagen, Denmark.
| |
Collapse
|
21
|
Intra- and interobserver variability of language mapping by navigated transcranial magnetic brain stimulation. BMC Neurosci 2013; 14:150. [PMID: 24304865 PMCID: PMC4235023 DOI: 10.1186/1471-2202-14-150] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 11/27/2013] [Indexed: 11/24/2022] Open
Abstract
Background Repetitive navigated transcranial magnetic stimulation (rTMS) has been used for studying language organization in healthy volunteers and patients, and to detect cortical areas involved in language processing. However, little is known about the reliability of this method. To determine the reliability of rTMS language mapping, we conducted both an interobserver and an intraobserver investigation. Methods Ten right-handed healthy subjects underwent language mapping by rTMS and the same object-naming task three times. Intraobserver and interobserver reliability of seven different error types were tested by two investigators. Analysis was performed blinded to the previous results and stimulated cortical sites. Results Overall, the results of both the interobserver and the intraobserver investigations show variable accordance. This is demonstrated by comparing the error rates of all different error types of the three examinations. Considering the most important error type, “no response”, there is only small variability in inter- and intraobserver mapping. Conclusions With our current protocol, interobserver and intraobserver comparisons only corresponded partially. Thus, although rTMS seems a promising method for preoperative planning as well as neuropsychological research, the current protocol needs further improvement.
Collapse
|