Functional MRI: Primary Motor Cortex Localization in Patients with Brain Tumors

Background: Hand-motor impairment affects a large proportion of multiple sclerosis (MS) patients; however, its substrates are still poorly understood. Objectives: To investigate the association between global disability, hand-motor impairment, and alterations in motor-relevant structural and functional magnetic resonance imaging (MRI) networks in MS patients with different clinical phenotypes. Methods: One hundred thirty-four healthy controls (HC) and 364 MS patients (250 relapsing-remitting MS (RRMS) and 114 progressive MS (PMS)) underwent Expanded Disability Status Scale (EDSS) rating, nine-hole peg test (9HPT), and electronic finger tapping rate (EFTR). Structural and resting state (RS) functional MRI scans were used to perform a source-based morphometry on gray matter (GM) components, to analyze white matter (WM) tract diffusivity indices and to perform a RS seed-based approach from the primary motor cortex involved in hand movement (hand-motor cortex). Random forest analyses identified the predictors of clinical impairment. Result: In RRMS, global measures of atrophy and lesions together with measures of structural damage of motor-related regions predicted EDSS (out-of-bag (OOB)- R2 = 0.19, p-range = <0.001–0.04), z9HPT (right: OOB- R2 = 0.14; left: OOB- R2 = 0.24, p-range = <0.001–0.03). No RS functional connectivity (FC) abnormalities were identified in RRMS models. In PMS, cerebellar and sensorimotor regions atrophy, cerebellar peduncles integrity and increased RS FC between left hand-motor cortex and right inferior frontal gyrus predicted EDSS (OBB- R2 = 0.16, p-range = 0.02–0.04). Conclusion: In RRMS, only measures of structural damage contribute to explain motor impairment, whereas both structural and functional MRI measures predict clinical disability in PMS. A multiparametric MRI approach could be relevant to investigate hand-motor impairment in different MS phenotypes.

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Normal aging and brain functional connectivity of primary motor cortex: a functional MRI (fMRI) study

Proceedings of the IEEE 28th Annual Northeast Bioengineering Conference (IEEE Cat. No.02CH37342) ◽

10.1109/nebc.2002.999511 ◽

2003 ◽

Cited By ~ 1

Author(s):

R.K. Niazy ◽

Maolin Qiu ◽

Zhensheng Deng ◽

J. Enderle ◽

Song Lai

Keyword(s):

Functional Connectivity ◽

Motor Cortex ◽

Functional Mri ◽

Primary Motor Cortex ◽

Normal Aging ◽

Fmri Study ◽

Brain Functional Connectivity

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Plasticity of the Primary Motor Cortex in Patients with Primary Brain Tumors

Neural Plasticity ◽

10.1155/2020/3648517 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9 ◽

Cited By ~ 2

Author(s):

Nathan W. Kong ◽

William R. Gibb ◽

Suvarna Badhe ◽

Benjamin P. Liu ◽

Matthew C. Tate

Keyword(s):

Motor Cortex ◽

Brain Tumors ◽

Growth Kinetics ◽

Neural Plasticity ◽

Primary Motor Cortex ◽

Brain Injuries ◽

Treatment Strategies ◽

Case Series ◽

Retrospective Case ◽

Motor Region

There are two neuron-level mechanisms proposed to underlie neural plasticity: recruiting neurons nearby to support the lost function (ipsilesional plasticity) and uncovering latent pathways that can assume the function that was lost (contralesional plasticity). While both patterns have been demonstrated in patient groups following injury, the specific mechanisms underlying each mode of plasticity are poorly understood. In a retrospective case series of 13 patients, we utilize a novel paradigm that analyzes serial fMRI scans in patients harboring intrinsic brain tumors that vary in location and growth kinetics to better understand the mechanisms underlying these two modes of plasticity in the human primary motor cortex. Twelve patients in our series had some degree of primary motor cortex plasticity, an area previously thought to have limited plasticity. Patients harboring smaller lesions with slower growth kinetics and increasing distance from the primary motor region demonstrated recruitment of ipsilateral motor regions. Conversely, larger, faster-growing lesions in close proximity to the primary motor region were associated with activation of the contralesional primary motor cortex, along with increased activation of the supplementary motor area. These data increase our understanding of the adaptive abilities of the brain and may lead to improved treatment strategies for those suffering from motor loss secondary to brain injuries.

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