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Taga M, Hong YNG, Charalambous CC, Raju S, Hayes L, Lin J, Zhang Y, Shao Y, Houston M, Zhang Y, Mazzoni P, Roh J, Schambra HM. Corticospinal and corticoreticulospinal projections benefit motor behaviors in chronic stroke. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.04.588112. [PMID: 38645144 PMCID: PMC11030245 DOI: 10.1101/2024.04.04.588112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
After corticospinal tract (CST) stroke, several motor deficits in the upper extremity (UE) emerge, including diminished muscle strength, motor control, and muscle individuation. Both the ipsilesional CST and contralesional corticoreticulospinal tract (CReST) innervate the paretic UE and may have different innervation patterns for the proximal and distal UE segments. These patterns may underpin distinct pathway relationships to separable motor behaviors. In this cross-sectional study of 15 chronic stroke patients and 28 healthy subjects, we examined two key questions: (1) whether segmental motor behaviors differentially relate to ipsilesional CST and contralesional CReST projection strengths, and (2) whether motor behaviors segmentally differ in the paretic UE. We measured strength, motor control, and muscle individuation in a proximal (biceps, BIC) and distal muscle (first dorsal interosseous, FDI) of the paretic UE. We measured the projection strengths of the ipsilesional CST and contralesional CReST to these muscles using transcranial magnetic stimulation (TMS). Stroke subjects had abnormal motor control and muscle individuation despite strength comparable to healthy subjects. In stroke subjects, stronger ipsilesional CST projections were linked to superior motor control in both UE segments, whereas stronger contralesional CReST projections were linked to superior muscle strength and individuation in both UE segments. Notably, both pathways also shared associations with behaviors in the proximal segment. Motor control deficits were segmentally comparable, but muscle individuation was worse for distal motor performance. These results suggest that each pathway has specialized contributions to chronic motor behaviors but also work together, with varying levels of success in supporting chronic deficits. Key points summary Individuals with chronic stroke typically have deficits in strength, motor control, and muscle individuation in their paretic upper extremity (UE). It remains unclear how these altered behaviors relate to descending motor pathways and whether they differ by proximal and distal UE segment.In this study, we used transcranial magnetic stimulation (TMS) to examine projection strengths of the ipsilesional corticospinal tract (CST) and contralesional corticoreticulospinal tract (CReST) with respect to quantitated motor behaviors in chronic stroke.We found that stronger ipsilesional CST projections were associated with better motor control in both UE segments, whereas stronger contralesional CReST projections were associated with better strength and individuation in both UE segments. In addition, projections of both pathways shared associations with motor behaviors in the proximal UE segment.We also found that deficits in strength and motor control were comparable across UE segments, but muscle individuation was worse with controlled movement in the distal UE segment.These results suggest that the CST and CReST have specialized contributions to chronic motor behaviors and also work together, although with different degrees of efficacy.
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Oquita R, Cuello V, Uppati S, Mannuru S, Salinas D, Dobbs M, Potter-Baker KA. Moving toward elucidating alternative motor pathway structures post-stroke: the value of spinal cord neuroimaging. Front Neurol 2024; 15:1282685. [PMID: 38419695 PMCID: PMC10899520 DOI: 10.3389/fneur.2024.1282685] [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: 08/25/2023] [Accepted: 01/29/2024] [Indexed: 03/02/2024] Open
Abstract
Stroke results in varying levels of motor and sensory disability that have been linked to the neurodegeneration and neuroinflammation that occur in the infarct and peri-infarct regions within the brain. Specifically, previous research has identified a key role of the corticospinal tract in motor dysfunction and motor recovery post-stroke. Of note, neuroimaging studies have utilized magnetic resonance imaging (MRI) of the brain to describe the timeline of neurodegeneration of the corticospinal tract in tandem with motor function following a stroke. However, research has suggested that alternate motor pathways may also underlie disease progression and the degree of functional recovery post-stroke. Here, we assert that expanding neuroimaging techniques beyond the brain could expand our knowledge of alternate motor pathway structure post-stroke. In the present work, we will highlight findings that suggest that alternate motor pathways contribute to post-stroke motor dysfunction and recovery, such as the reticulospinal and rubrospinal tract. Then we review imaging and electrophysiological techniques that evaluate alternate motor pathways in populations of stroke and other neurodegenerative disorders. We will then outline and describe spinal cord neuroimaging techniques being used in other neurodegenerative disorders that may provide insight into alternate motor pathways post-stroke.
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Affiliation(s)
- Ramiro Oquita
- School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, United States
| | - Victoria Cuello
- School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, United States
| | - Sarvani Uppati
- School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, United States
| | - Sravani Mannuru
- School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, United States
| | - Daniel Salinas
- Department of Neuroscience, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, United States
| | - Michael Dobbs
- Department of Clinical Neurosciences, College of Medicine, Florida Atlantic University, Boca Raton, FL, United States
| | - Kelsey A. Potter-Baker
- Department of Neuroscience, School of Medicine, University of Texas Rio Grande Valley, Edinburg, TX, United States
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Li X, Baker KB, O’Laughlin K, Chen J, Hogue O, Machado AG, Plow EB. Paired DBS and TMS Reveals Dentato-Cortical Facilitation Underlying Upper Extremity Movement in Chronic Stroke Survivors. Neurorehabil Neural Repair 2024; 38:109-121. [PMID: 38156644 PMCID: PMC10922453 DOI: 10.1177/15459683231219265] [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] [Indexed: 01/03/2024]
Abstract
BACKGROUND Cerebellum shares robust di-synaptic dentato-thalamo-cortical (DTC) connections with the contralateral motor cortex. Preclinical studies have shown that DTC are excitatory in nature. Structural integrity of DTC is associated with better upper extremity (UE) motor function in people with stroke, indicating DTC are important for cerebellar influences on movement. However, there is a lack of understanding of physiologic influence of DTC in humans, largely due to difficulty in accessing the dentate nucleus. OBJECTIVE Characterize DTC physiology using dentate nucleus deep brain stimulation (DBS) combined with transcranial magnetic stimulation (TMS) in stroke. METHODS Nine chronic stroke survivors with moderate-to-severe UE impairment (Fugl-Meyer 13-38) underwent a paired DBS-TMS experiment before receiving experimental dentate nucleus DBS in our first-in-human phase I trial (Baker et al., 2023, Nature Medicine). Conditioning DBS pulses were given to dentate nucleus 1 to 10 ms prior to supra-threshold TMS pulses given to ipsilesional motor cortex. Effects were assessed on motor evoked potentials (MEPs). Size of DBS-conditioned MEPs was expressed relative to TMS MEPs, where values >1 indicate facilitation. RESULTS Dentate nucleus DBS led to facilitation of MEPs at short-latency intervals (3.5 and 5 ms, P = .049 and .021, respectively), a phenomenon we have termed dentato-cortical facilitation (DCF). Higher DCF was observed among patients with more severe UE impairment. Diffusion tensor imaging revealed microstructure of thalamo-cortical portion of DTC was related to higher corticomotor excitability. CONCLUSIONS Our in vivo investigation reveals for the first time in humans the intrinsic excitatory properties of DTC, which can serve as a novel therapeutic target for post-stroke motor recovery.
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Affiliation(s)
- Xin Li
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Kenneth B. Baker
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Kyle O’Laughlin
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Jacqueline Chen
- Department of Diagnostic Radiology, Imaging Institute, Cleveland Clinic, Cleveland, OH 44106, USA
| | - Olivia Hogue
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Andre G. Machado
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, Cleveland, OH 44195, USA
- Department of Neurosurgery, Neurological 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
- Cleveland Clinic Rehabilitation Hospitals, Department of Physical Medicine and Rehabilitation, Cleveland Clinic, Cleveland, OH 44195, USA
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Hayes L, Taga M, Charalambous CC, Raju S, Lin J, Schambra HM. The distribution of transcallosal inhibition to upper extremity muscles is altered in chronic stroke. J Neurol Sci 2023; 450:120688. [PMID: 37224604 DOI: 10.1016/j.jns.2023.120688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 04/25/2023] [Accepted: 05/11/2023] [Indexed: 05/26/2023]
Abstract
OBJECTIVE To determine if the distribution of transcallosal inhibition (TI) acting on proximal and distal upper extremity muscles is altered in chronic stroke. METHODS We examined thirteen healthy controls and sixteen mildly to moderately impaired chronic stroke patients. We used transcranial magnetic stimulation (TMS) to probe TI from the contralesional onto ipsilesional hemisphere (assigned in controls). We recorded the ipsilateral silent period in the paretic biceps (BIC) and first dorsal interosseous (FDI). We measured TI strength, distribution gradient (TI difference between muscles), and motor impairment (Fugl-Meyer Assessment). RESULTS Both groups had stronger TI acting on their FDIs than BICs (p < 0.001). However, stroke patients also had stronger TI acting on their BICs than controls (p = 0.034), resulting in a flatter distribution of inhibition (p = 0.028). In patients, stronger FDI inhibition correlated with less hand impairment (p = 0.031); BIC inhibition was not correlated to impairment. CONCLUSION TI is more evenly distributed to the paretic FDI and BIC in chronic stroke. The relative increase in proximal inhibition does not relate to better function, as it does distally. SIGNIFICANCE The results expand our knowledge about segment-specific neurophysiology and its relevance to impairment after stroke.
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Affiliation(s)
- Leticia Hayes
- Department of Neurology, NYU Grossman School of Medicine, New York, United States.
| | - Myriam Taga
- Department of Neurology, NYU Grossman School of Medicine, New York, United States.
| | - Charalambos C Charalambous
- Department of Basic and Clinical Sciences, University of Nicosia Medical School, Nicosia, Cyprus; Center for Neuroscience and Integrative Brain Research (CENIBRE), University of Nicosia Medical School, Nicosia, Cyprus.
| | - Sharmila Raju
- Department of Neurology, NYU Grossman School of Medicine, New York, United States.
| | - Jing Lin
- Department of Rehabilitation Medicine, NYU Grossman School of Medicine, New York, United States.
| | - Heidi M Schambra
- Department of Neurology, NYU Grossman School of Medicine, New York, United States; Department of Rehabilitation Medicine, NYU Grossman School of Medicine, New York, United States.
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Andrushko JW, Levenstein JM, Zich C, Edmond EC, Campbell J, Clarke WT, Emir U, Farthing JP, Stagg CJ. Repeated unilateral handgrip contractions alter functional connectivity and improve contralateral limb response times. Sci Rep 2023; 13:6437. [PMID: 37081073 PMCID: PMC10119116 DOI: 10.1038/s41598-023-33106-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 04/07/2023] [Indexed: 04/22/2023] Open
Abstract
In humans, motor learning is underpinned by changes in sensorimotor network functional connectivity (FC). Unilateral contractions increase FC in the ipsilateral primary motor cortex (M1) and supplementary motor area (SMA); areas involved in motor planning and execution of the contralateral hand. Therefore, unilateral contractions are a promising approach to augment motor performance in the contralateral hand. In a within-participant, randomized, cross-over design, 15 right-handed adults had two magnetic resonance imaging (MRI) sessions, where functional-MRI and MR-Spectroscopic Imaging were acquired before and after repeated right-hand contractions at either 5% or 50% maximum voluntary contraction (MVC). Before and after scanning, response times (RTs) were determined in both hands. Nine minutes of 50% MVC contractions resulted in decreased handgrip force in the contracting hand, and decreased RTs and increased handgrip force in the contralateral hand. This improved motor performance in the contralateral hand was supported by significant neural changes: increased FC between SMA-SMA and increased FC between right M1 and right Orbitofrontal Cortex. At a neurochemical level, the degree of GABA decline in left M1, left and right SMA correlated with subsequent behavioural improvements in the left-hand. These results support the use of repeated handgrip contractions as a potential modality for improving motor performance in the contralateral hand.
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Affiliation(s)
- Justin W Andrushko
- College of Kinesiology, University of Saskatchewan, Saskatoon, Canada.
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK.
| | - Jacob M Levenstein
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
- Section on Functional Imaging Methods, National Institutes of Mental Health, National Institutes of Health, Bethesda, MD, USA
- Thompson Institute, University of the Sunshine Coast, Sippy Downs, Australia
| | - Catharina Zich
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
- Department of Clinical and Movement Neurosciences, University College London, London, UK
| | - Evan C Edmond
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Jon Campbell
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - William T Clarke
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
| | - Uzay Emir
- School of Health Sciences, College of Health and Human Sciences, Purdue University, West Lafayette, USA
| | | | - Charlotte J Stagg
- FMRIB, Nuffield Department of Clinical Neurosciences, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford, UK
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Ye S, Pan H, Li W, Wang J, Zhang H. Development and validation of a clinical nomogram for differentiating hemorrhagic and ischemic stroke prehospital. BMC Neurol 2023; 23:95. [PMID: 36864378 PMCID: PMC9983153 DOI: 10.1186/s12883-023-03138-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 02/27/2023] [Indexed: 03/04/2023] Open
Abstract
OBJECTIVES The early detection and identification of stroke are essential to the prognosis of patients with suspected stroke symptoms out-of-hospital. We aimed to develop a risk prediction model based on the FAST score to identify the different types of strokes early for emergency medical services (EMS). METHODS This retrospective observational study enrolled 394 stroke patients at a single center from January 2020 to December 2021. Demographic data, clinical characteristics, and stroke risk factors with patients were collected from the EMS record database. Univariate and multivariate logistic regression analysis was used to identify the independent risk predictors. The nomogram was developed based on the independent predictors, in which the discriminative value and calibration of the nomogram were verified by the receiver operator characteristic (ROC) curve and calibration plots. RESULTS A total of 31.90% (88/276) of patients were diagnosed with hemorrhagic stroke in the training set, while 36.40% (43/118) in the validation set. The nomogram was developed based on the multivariate analysis, including age, systolic blood pressure, hypertension, vomiting, arm weakness, and slurred speech. The area under the curve (AUC) of the ROC with nomogram was 0.796 (95% CI: 0.740-0.852, P < 0.001) and 0.808 (95% CI:0.728-0.887, P < 0.001) in the training set and validation set, respectively. In addition, the AUC with the nomogram was superior to the FAST score in both two sets. The calibration curve showed a good agreement with the nomogram and the decision curves analysis also demonstrated that the nomogram had a wider range of threshold probabilities than the FAST score in the prediction risk of hemorrhagic stroke. CONCLUSIONS This novel noninvasive clinical nomogram shows a good performance in differentiating hemorrhagic and ischemic stroke for EMS staff prehospital. Moreover, all of the variables of nomogram are acquired in clinical practice easily and inexpensively out-of-hospital.
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Affiliation(s)
- Sheng Ye
- grid.443626.10000 0004 1798 4069Department of Emergency Medicine, The Second Affiliated Hospital of Wannan Medical College, Wuhu, Anhui China ,grid.443626.10000 0004 1798 4069Emergency Sub-Station, The Second Affiliated Hospital of Wannan Medical College, Wuhu, Anhui China
| | - Huiqing Pan
- grid.443626.10000 0004 1798 4069Department of Emergency Medicine, The Second Affiliated Hospital of Wannan Medical College, Wuhu, Anhui China ,grid.443626.10000 0004 1798 4069Emergency Sub-Station, The Second Affiliated Hospital of Wannan Medical College, Wuhu, Anhui China
| | - Weijia Li
- grid.443626.10000 0004 1798 4069School of Clinical Medicine, Wannan Medical College, Wuhu, Anhui China
| | - Jinqiang Wang
- grid.443626.10000 0004 1798 4069Emergency Sub-Station, The Second Affiliated Hospital of Wannan Medical College, Wuhu, Anhui China ,Department of Emergency Medicine, Wuhu Emergency Medical Center, Wuhu, Anhui China
| | - Hailong Zhang
- Emergency Sub-Station, The Second Affiliated Hospital of Wannan Medical College, Wuhu, Anhui, China. .,Department of Emergency Medicine, Wuhu Emergency Medical Center, Wuhu, Anhui, China.
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Phan T, Nguyen H, Vermillion BC, Kamper DG, Lee SW. Abnormal proximal-distal interactions in upper-limb of stroke survivors during object manipulation: A pilot study. Front Hum Neurosci 2022; 16:1022516. [PMID: 36405084 PMCID: PMC9673127 DOI: 10.3389/fnhum.2022.1022516] [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: 08/18/2022] [Accepted: 10/18/2022] [Indexed: 11/06/2022] Open
Abstract
Despite its importance, abnormal interactions between the proximal and distal upper extremity muscles of stroke survivors and their impact on functional task performance has not been well described, due in part to the complexity of upper extremity tasks. In this pilot study, we elucidated proximal-distal interactions and their functional impact on stroke survivors by quantitatively delineating how hand and arm movements affect each other across different phases of functional task performance, and how these interactions are influenced by stroke. Fourteen subjects, including nine chronic stroke survivors and five neurologically-intact subjects participated in an experiment involving transport and release of cylindrical objects between locations requiring distinct proximal kinematics. Distal kinematics of stroke survivors, particularly hand opening, were significantly affected by the proximal kinematics, as the hand aperture decreased and the duration of hand opening increased at the locations that requires shoulder abduction and elbow extension. Cocontraction of the extrinsic hand muscles of stroke survivors significantly increased at these locations, where an increase in the intermuscular coherence between distal and proximal muscles was observed. Proximal kinematics of stroke survivors was also affected by the finger extension, but the cocontraction of their proximal muscles did not significantly increase, suggesting the changes in the proximal kinematics were made voluntarily. Our results showed significant proximal-to-distal interactions between finger extension and elbow extension/shoulder abduction of stroke survivors exist during their functional movements. Increased cocontraction of the hand muscles due to increased neural couplings between the distal and proximal muscles appears to be the underlying mechanism.
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Affiliation(s)
- Thanh Phan
- Department of Biomedical Engineering, Catholic University of America, Washington, DC, United States
| | - Hien Nguyen
- Center for Applied Biomechanics and Rehabilitation Research, National Rehabilitation Hospital, Washington, DC, United States
| | - Billy C. Vermillion
- Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, United States
| | - Derek G. Kamper
- UNC/NC State Joint Department of Biomedical Engineering, North Carolina State University, Raleigh, NC, United States,Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL, United States
| | - Sang Wook Lee
- Department of Biomedical Engineering, Catholic University of America, Washington, DC, United States,Center for Applied Biomechanics and Rehabilitation Research, National Rehabilitation Hospital, Washington, DC, United States,Department of Mechanical Engineering, Korean Advanced Institute of Science and Technology, Daejeon, South Korea,*Correspondence: Sang Wook Lee,
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Charalambous CC, Hadjipapas A. Is there frequency-specificity in the motor control of walking? The putative differential role of alpha and beta oscillations. Front Syst Neurosci 2022; 16:922841. [PMID: 36387306 PMCID: PMC9650482 DOI: 10.3389/fnsys.2022.922841] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 10/14/2022] [Indexed: 11/04/2023] Open
Abstract
Alpha and beta oscillations have been assessed thoroughly during walking due to their potential role as proxies of the corticoreticulospinal tract (CReST) and corticospinal tract (CST), respectively. Given that damage to a descending tract after stroke can cause walking deficits, detailed knowledge of how these oscillations mechanistically contribute to walking could be utilized in strategies for post-stroke locomotor recovery. In this review, the goal was to summarize, synthesize, and discuss the existing evidence on the potential differential role of these oscillations on the motor descending drive, the effect of transcranial alternate current stimulation (tACS) on neurotypical and post-stroke walking, and to discuss remaining gaps in knowledge, future directions, and methodological considerations. Electrophysiological studies of corticomuscular, intermuscular, and intramuscular coherence during walking clearly demonstrate that beta oscillations are predominantly present in the dorsiflexors during the swing phase and may be absent post-stroke. The role of alpha oscillations, however, has not been pinpointed as clearly. We concluded that both animal and human studies should focus on the electrophysiological characterization of alpha oscillations and their potential role to the CReST. Another approach in elucidating the role of these oscillations is to modulate them and then quantify the impact on walking behavior. This is possible through tACS, whose beneficial effect on walking behavior (including boosting of beta oscillations in intramuscular coherence) has been recently demonstrated in both neurotypical adults and stroke patients. However, these studies still do not allow for specific roles of alpha and beta oscillations to be delineated because the tACS frequency used was much lower (i.e., individualized calculated gait frequency was used). Thus, we identify a main gap in the literature, which is tACS studies actually stimulating at alpha and beta frequencies during walking. Overall, we conclude that for beta oscillations there is a clear connection to descending drive in the corticospinal tract. The precise relationship between alpha oscillations and CReST remains elusive due to the gaps in the literature identified here. However, better understanding the role of alpha (and beta) oscillations in the motor control of walking can be used to progress and develop rehabilitation strategies for promoting locomotor recovery.
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Affiliation(s)
- Charalambos C. Charalambous
- Department of Basic and Clinical Sciences, Medical School, University of Nicosia, Nicosia, Cyprus
- Center for Neuroscience and Integrative Brain Research (CENIBRE), Medical School, University of Nicosia, Nicosia, Cyprus
| | - Avgis Hadjipapas
- Department of Basic and Clinical Sciences, Medical School, University of Nicosia, Nicosia, Cyprus
- Center for Neuroscience and Integrative Brain Research (CENIBRE), Medical School, University of Nicosia, Nicosia, Cyprus
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Russell C, Difford N, Stamenkovic A, Stapley P, McAndrew D, Arpel C, MacKinnon C, Shemmell J. Postural support requirements preferentially modulate late components of the gastrocnemius response to transcranial magnetic stimulation. Exp Brain Res 2022; 240:2647-2657. [PMID: 36006434 PMCID: PMC9510120 DOI: 10.1007/s00221-022-06440-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 08/05/2022] [Indexed: 11/27/2022]
Abstract
Mounting evidence suggests that motor evoked potentials (MEPs) recorded in upper limb muscles with postural support roles following transcranial magnetic stimulation receive contributions from both corticospinal and non-corticospinal descending pathways. We tested the hypothesis that neural structures responsible for regulating upright balance are involved in transmitting late portions of TMS-induced MEPs in a lower limb muscle. MEPs were recorded in the medial gastrocnemius muscles of each leg, while participants supported their upright posture in five postural conditions that required different levels of support from the target muscles. We observed that early and late portions of the MEP were modulated independently, with early MEP amplitude being reduced when high levels of postural support were required from a target muscle. Independent modulation of early and late MEPs by altered postural demand suggests largely separable transmission of each part of the MEP. The early component of the MEP is likely generated by fast-conducting corticospinal pathways, whereas the later component may be primarily transmitted along a polysynaptic cortico-reticulospinal pathway.
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Affiliation(s)
- Cassandra Russell
- School of Medical, Indigenous and Health Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Building 41, Northfields Avenue, Wollongong, NSW, 2522, Australia
| | - Nathan Difford
- School of Medical, Indigenous and Health Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Building 41, Northfields Avenue, Wollongong, NSW, 2522, Australia
| | - Alexander Stamenkovic
- Department of Physical Therapy, College of Health Professions, Virgina Commonwealth University, Richmond, USA
| | - Paul Stapley
- School of Medical, Indigenous and Health Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Building 41, Northfields Avenue, Wollongong, NSW, 2522, Australia
| | - Darryl McAndrew
- School of Medical, Indigenous and Health Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Building 41, Northfields Avenue, Wollongong, NSW, 2522, Australia
| | - Caitlin Arpel
- School of Medical, Indigenous and Health Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Building 41, Northfields Avenue, Wollongong, NSW, 2522, Australia
| | - Colum MacKinnon
- Department of Neurology, University of Minnesota, Minneapolis, USA
| | - Jonathan Shemmell
- School of Medical, Indigenous and Health Sciences, Faculty of Science, Medicine and Health, University of Wollongong, Building 41, Northfields Avenue, Wollongong, NSW, 2522, Australia.
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Boyne P, DiFrancesco M, Awosika OO, Williamson B, Vannest J. Mapping the human corticoreticular pathway with multimodal delineation of the gigantocellular reticular nucleus and high-resolution diffusion tractography. J Neurol Sci 2022; 434:120091. [PMID: 34979371 PMCID: PMC8957549 DOI: 10.1016/j.jns.2021.120091] [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: 08/28/2021] [Revised: 11/17/2021] [Accepted: 12/10/2021] [Indexed: 11/29/2022]
Abstract
The corticoreticular pathway (CRP) is a major motor tract that transmits cortical input to the reticular formation motor nuclei and may be an important mediator of motor recovery after central nervous system damage. However, its cortical origins, trajectory and laterality are incompletely understood in humans. This study aimed to map the human CRP and generate an average CRP template in standard MRI space. Following recently established guidelines, we manually delineated the primary reticular formation motor nucleus (gigantocellular reticular nucleus [GRN]) using several group-mean MRI contrasts from the Human Connectome Project (HCP). CRP tractography was then performed with HCP diffusion-weighted MRI data (N = 1065) by selecting diffusion streamlines that reached both the cortex and GRN. Corticospinal tract (CST) tractography was also performed for comparison. Results suggest that the human CRP has widespread origins, which overlap with the CST across most of the motor cortex and include additional exclusive inputs from the medial and anterior prefrontal cortices. The estimated CRP projected through the anterior and posterior limbs of the internal capsule before partially decussating in the midbrain tegmentum and converging bilaterally on the pontomedullary reticular formation. Thus, the CRP trajectory appears to partially overlap the CST, while being more distributed and anteromedial to the CST in the cerebrum before moving posterior to the CST in the brainstem. These findings have important implications for neurophysiologic testing, cortical stimulation and movement recovery after brain lesions. We expect that our GRN and tract maps will also facilitate future CRP research.
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Affiliation(s)
- Pierce Boyne
- Department of Rehabilitation, Exercise and Nutrition Sciences, College of Allied Health Sciences, University of Cincinnati, Cincinnati, OH 45267, USA.
| | - Mark DiFrancesco
- Department of Radiology and Pediatric Neuroimaging Research Consortium, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45267, USA
| | - Oluwole O Awosika
- Department of Neurology and Rehabilitation Medicine, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Brady Williamson
- Department of Radiology, College of Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Jennifer Vannest
- Department of Communication Sciences and Disorders, College of Allied Health Sciences, University of Cincinnati, Cincinnati, OH 45267, USA
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