Altered Motor Excitability in Patients With Diffuse Gliomas Involving Motor Eloquent Areas: The Impact of Tumor Grading

Lavrador, José Pedro; Gioti, Ifigeneia; Hoppe, Szymon; Jung, Josephine; Patel, Sabina; Gullan, Richard; Ashkan, Keyoumars; Bhangoo, Ranjeev; Vergani, Francesco

doi:10.1093/neuros/nyaa354

Cited by 31 publications

(29 citation statements)

References 32 publications

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“…Further studies are needed to investigate more deeply the relationship between presurgical plastic reorganization and functional outcomes following resection, by also taking account of the various cognitive profiles before surgery, and the tumor features, i.e., its volume, its grade (LGG vs. HGG) [99], as well as its location. Indeed, a recent TMS study showed that the preoperative excitability of the motor eloquent areas (assessed using a cortical excitability score, which evaluates the number of abnormal inter-hemispheric resting motor threshold ratios) was significantly increased in isocitrate dehydrogenase wild-type gliomas [100]. Moreover, Vergani et al [101] compared LGG in contact with the subventricular zone (SVZ) versus LGG not in contact with the SVZ.…”

Section: Preoperative Prediction Of Postoperative Functional Outcomes Based On Fni/tmsmentioning

confidence: 99%

Functional Mapping before and after Low-Grade Glioma Surgery: A New Way to Decipher Various Spatiotemporal Patterns of Individual Neuroplastic Potential in Brain Tumor Patients

Duffau

2020

Cancers

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Intraoperative direct electrostimulation mapping (DEM) is currently the gold-standard for glioma surgery, since functional-based resection allows an optimization of the onco-functional balance (increased resection with preserved quality of life). Besides intrasurgical awake mapping of conation, cognition, and behavior, preoperative mapping by means of functional neuroimaging (FNI) and transcranial magnetic stimulation (TMS) has increasingly been utilized for surgical selection and planning. However, because these techniques suffer from several limitations, particularly for direct functional mapping of subcortical white matter pathways, DEM remains crucial to map neural connectivity. On the other hand, non-invasive FNI and TMS can be repeated before and after surgical resection(s), enabling longitudinal investigation of brain reorganization, especially in slow-growing tumors like low-grade gliomas. Indeed, these neoplasms generate neuroplastic phenomena in patients with usually no or only slight neurological deficits at diagnosis, despite gliomas involving the so-called “eloquent” structures. Here, data gained from perioperative FNI/TMS mapping methods are reviewed, in order to decipher mechanisms underpinning functional cerebral reshaping induced by the tumor and its possible relapse, (re)operation(s), and postoperative rehabilitation. Heterogeneous spatiotemporal patterns of rearrangement across patients and in a single patient over time have been evidenced, with structural changes as well as modifications of intra-hemispheric (in the ipsi-lesional and/or contra-lesional hemisphere) and inter-hemispheric functional connectivity. Such various fingerprints of neural reconfiguration were correlated to different levels of cognitive compensation. Serial multimodal studies exploring neuroplasticity might lead to new management strategies based upon multistage therapeutic approaches adapted to the individual profile of functional reallocation.

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Section: Preoperative Prediction Of Postoperative Functional Outcomes Based On Fni/tmsmentioning

confidence: 99%

Functional Mapping before and after Low-Grade Glioma Surgery: A New Way to Decipher Various Spatiotemporal Patterns of Individual Neuroplastic Potential in Brain Tumor Patients

Duffau

2020

Cancers

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“… No adverse events Rohde V et al, 2003 16 X 70–90% x RTM The use of intraoperative repetitive nTMS was capable of correctly identifying 92% of the primary motor cortex x Gimramov R F, 2002 21 Figure-of-eight stimulation coil x x RTM Patients with tumors in the brainstem or the motor area had higher RMT thresholds compared to healthy subjects. x Machetanz K et al, 2021 44 Figure-of-eight stimulation coil 110% X RMT/latency/amplitude Patients with apparent paresis had higher RMT than healthy patients or patients without apparent paresis. x Neville I S et al, 2021 42 x 120–140% x RMT The hemisphere with tumors presented different excitability compared to the healthy hemisphere.…”

Section: Resultsmentioning

confidence: 99%

“… 43 Also, a study found that patients with high tumor grades had the excitability pattern of the hemisphere different from the low tumor grades patients. 44 …”

Section: Resultsmentioning

confidence: 99%

Assessing the Capabilities of Transcranial Magnetic Stimulation (TMS) to Aid in the Removal of Brain Tumors Affecting the Motor Cortex: A Systematic Review

Schiavao¹,

Neville²,

Hayashi³

et al. 2022

NDT

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Introduction The brain tumor is frequently related to severe motor impairment and impacts the quality of life. The corticospinal tract can sometimes be affected depending on the type and size of the neoplasm, so different tools can evaluate motor function and connections. It is essential to organize surgical procedures and plan the approach. Functional motor status is mapped before, during, and after surgery. Studying corticospinal tract status can help map the functional areas, predict postoperative outcomes, and help the decision, reducing neurological deficits, aiming to preserve functional networks, using the concepts of white matters localization and fibbers connections. Nowadays, there are new techniques that provide functional information regarding the motor cortex, such as transcranial magnetic stimulation (TMS), direct cortical stimulation (DCS), and navigated TMS (nTMS). These tools can be used to plan a customized surgical strategy and the role of motor evoked potentials (MEPs) is well described during intra-operative, using intraoperative neuromonitoring. MEPs can help to localize primary motor areas and delineate the cut-off point of resection in real-time, using direct stimulation. In the post-operative, the MEP has increased your function as a predictive marker of permanent or transitory neurological lesion marker. Methods Systematic review performed in MEDLINE via PUBMED, EMBASE, and SCOPUS databases regarding the post-operative assessment of MEP in patients with brain tumors. The search strategy included the following terms: ((“Evoked Potentials, Motor”[Mesh]) AND “Neoplasms”[Mesh]) AND “Transcranial Magnetic Stimulation”[Mesh] AND “Brain Tumor”[Mesh]), the analysis followed the PRISMA guidelines for systematic reviews, the review spanned until 06/04/2021, inclusion criteria were studies presenting confirmed diagnosis of brain tumor (primary or metastatic), patients >18 y/o, using TMS, Navigated TMS, and/or Evoked Potentials as tools in preoperative planning or at the intra-operative helping the evaluation of the neurological status of the motor cortex, articles published in peer-reviewed journals, and written in English or Portuguese. Results A total of 38 studies were selected for this review, of which 14 investigated the potential of nTMS to predict the occurrence of motor deficits, while 25 of the articles investigated the capabilities of the nTMS technique in performing pre/intraoperative neuro mapping of the motor cortex. Conclusion Further studies regarding motor function assessment are needed and standardized protocols for MEPs also need to be defined.

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“…For example, an abnormal RMT ratio, i.e. the ratio between the RMTs of both hemispheres, can be used as a marker of disease progression, for example in patients with brain tumors (Lavrador et al 2020;Rosenstock et al 2017;Tozlu et al 2020).…”

Section: Discussionmentioning

confidence: 99%

No impact of functional connectivity of the motor system on the resting motor threshold: A replication study

Engelhardt

Komnenić

Roth

et al. 2020

Preprint

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The physiological mechanisms of corticospinal excitability and factors influencing its measurement with transcranial magnetic stimulation are still poorly understood. A recent study reported an impact of functional connectivity between the primary motor cortex and dorsal premotor cortex on the resting motor threshold of the dominant hemisphere. We aimed to replicate these findings in a larger sample of 38 healthy right-handed subjects with data from both hemispheres. Resting-state functional connectivity was assessed between the primary motor cortex and five a-priori defined motor-relevant regions on each hemisphere as well as interhemispherically between both primary motor cortices. Following the procedure by the original authors, we included age, the cortical grey matter volume and coil to cortex distance as further predictors in the analysis. We report replication models for the dominant hemisphere as well as an extension to data from both hemispheres and support the results with Bayes factors. Functional connectivity between the primary motor cortex and dorsal premotor cortex did not explain variability in the resting motor threshold and we obtained moderate evidence for the absence of this effect. In contrast, coil to cortex distance could be confirmed as an important predictor with strong evidence. These findings contradict the previously proposed effect, thus questioning the notion of the dorsal premotor cortex playing a major role in modifying corticospinal excitability.

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Altered Motor Excitability in Patients With Diffuse Gliomas Involving Motor Eloquent Areas: The Impact of Tumor Grading

Cited by 31 publications

References 32 publications

Functional Mapping before and after Low-Grade Glioma Surgery: A New Way to Decipher Various Spatiotemporal Patterns of Individual Neuroplastic Potential in Brain Tumor Patients

Functional Mapping before and after Low-Grade Glioma Surgery: A New Way to Decipher Various Spatiotemporal Patterns of Individual Neuroplastic Potential in Brain Tumor Patients

Assessing the Capabilities of Transcranial Magnetic Stimulation (TMS) to Aid in the Removal of Brain Tumors Affecting the Motor Cortex: A Systematic Review

No impact of functional connectivity of the motor system on the resting motor threshold: A replication study

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