Lefebvre, G; Tremblay, S; Théoret, H
Probing the effects of mild traumatic brain injury with transcranial magnetic stimulation of the primary motor cortex Journal Article
In: Brain Injury, vol. 29, no. 9, pp. 1032–1043, 2015.
Abstract | Links | BibTeX | Tags: 4 aminobutyric acid B receptor, adult, aged, Article, brain concussion, brain cortex, Brain Injuries, central motor conduction time, clinical assessment, Concussion, cortical excitability, electrostimulation, evoked muscle response, Evoked Potentials, Female, human, Humans, Inhibition, latent inhibition, latent period, long interval intracortical inhibition, magnetic stimulation, Male, Medline, middle aged, Motor, motor cortex, motor evoked potential, motor nerve conduction, muscle contraction, nerve cell excitability, nerve cell plasticity, neuromuscular facilitation, Neuronal Plasticity, outcome assessment, paired associative stimulation, Pathophysiology, PHYSIOLOGY, postsynaptic inhibition, primary motor cortex, procedures, short interval intracortical inhibition, short latency afferent inhibition, sport injury, stimulus response, Systematic Review, therapy effect, theta burst stimulation, TRANSCRANIAL magnetic stimulation, traumatic brain injury, Young Adult
@article{Lefebvre2015,
title = {Probing the effects of mild traumatic brain injury with transcranial magnetic stimulation of the primary motor cortex},
author = {Lefebvre, G and Tremblay, S and Th\'{e}oret, H},
doi = {10.3109/02699052.2015.1028447},
year = {2015},
date = {2015-01-01},
journal = {Brain Injury},
volume = {29},
number = {9},
pages = {1032--1043},
abstract = {Primary objective: The present paper systematically reviews studies using transcranial magnetic stimulation (TMS) over the primary motor cortex (M1) to assess cortical excitability, intra-cortical inhibition/facilitation and synaptic plasticity following mild traumatic brain injury (mTBI).Methods: Articles using TMS over M1 in patients with mTBI or sport-related concussion indexed in PubMed and published between 1998 and September 2014 were included in the present review.Main outcomes and results: From the 17 articles that matched search criteria, results from various TMS paradigms were summarized and divided in three main areas of interest: motor cortical excitability/facilitation, motor cortical inhibition and cortical plasticity. Although studies suggest a trend of abnormal intra-cortical inhibition following mTBI, no clear and specific pattern emerges from the surveyed data.Conclusions: At this time and with the possible exception of intra-cortical inhibitory measures, TMS cannot reliably detect changes in M1 excitability in individuals with mTBI or a concussion at both the acute and chronic stages of injury. This may be explained by the small number of studies and large variety of stimulation parameters. Additional longitudinal and multimodal studies are needed to better understand the nature of the excitability changes that may occur within M1 following mTBI. © 2015 Taylor \& Francis Group, LLC.},
keywords = {4 aminobutyric acid B receptor, adult, aged, Article, brain concussion, brain cortex, Brain Injuries, central motor conduction time, clinical assessment, Concussion, cortical excitability, electrostimulation, evoked muscle response, Evoked Potentials, Female, human, Humans, Inhibition, latent inhibition, latent period, long interval intracortical inhibition, magnetic stimulation, Male, Medline, middle aged, Motor, motor cortex, motor evoked potential, motor nerve conduction, muscle contraction, nerve cell excitability, nerve cell plasticity, neuromuscular facilitation, Neuronal Plasticity, outcome assessment, paired associative stimulation, Pathophysiology, PHYSIOLOGY, postsynaptic inhibition, primary motor cortex, procedures, short interval intracortical inhibition, short latency afferent inhibition, sport injury, stimulus response, Systematic Review, therapy effect, theta burst stimulation, TRANSCRANIAL magnetic stimulation, traumatic brain injury, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Mayer, A R; Ling, J M; Dodd, A B; Gasparovic, C; Klimaj, S D; Meier, T B
A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters Journal Article
In: Journal of Neurotrauma, vol. 32, no. 22, pp. 1759–1767, 2015.
Abstract | Links | BibTeX | Tags: Adolescent, adult, Article, biological marker, Biomarkers, BRAIN chemistry, brain concussion, brain cortex, brain size, Cerebral Cortex, CHOLINE, clinical article, cognition, Concussion, controlled study, cortical thickness (brain), creatine, executive function, Female, follow up, Follow-Up Studies, frontal gyrus, glutamic acid, glutamine, human, Humans, Injuries, inositol, Longitudinal, Longitudinal studies, longitudinal study, Magnetic Resonance Imaging, Male, martial art, Martial Arts, Memory, middle aged, mixed martial art, n acetylaspartic acid, neuropsychological test, Neuropsychological Tests, nuclear magnetic resonance imaging, NUCLEAR magnetic resonance spectroscopy, occipital cortex, pathology, posterior cingulate, psychology, repetitive injury, Spectroscopy, volumetrics, white matter, Young Adult
@article{Mayer2015b,
title = {A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters},
author = {Mayer, A R and Ling, J M and Dodd, A B and Gasparovic, C and Klimaj, S D and Meier, T B},
doi = {10.1089/neu.2014.3833},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
number = {22},
pages = {1759--1767},
abstract = {Growing evidence suggests that temporally proximal acute concussions and repetitive subconcussive head injuries may lead to long-term neurological deficits. However, the underlying mechanisms of injury and their relative time-scales are not well documented in human injury models. The current study therefore investigated whether biomarkers of brain chemistry (magnetic resonance [MR] spectroscopy: N-acetylaspartate [NAA], combined glutamate and glutamine [Glx], total creatine [Cre], choline compounds [Cho], and myo-inositol [mI]) and structure (cortical thickness, white matter [WM]/subcortical volume) differed between mixed martial artists (MMA; n = 13) and matched healthy controls (HC) without a history of contact sport participation (HC; n = 14). A subset of participants (MMA = 9; HC = 10) returned for follow-up visits, with MMA (n = 3) with clinician-documented acute concussions also scanned serially. As expected, MMA self-reported a higher incidence of previous concussions and significantly more cognitive symptoms during prior concussion recovery. Fighters also exhibited reduced memory and processing speed relative to controls on neuropsychological testing coupled with cortical thinning in the left posterior cingulate gyrus and right occipital cortex at baseline assessment. Over a 1-year follow-up period, MMA experienced a significant decrease in both WM volume and NAA concentration, as well as relative thinning in the left middle and superior frontal gyri. These longitudinal changes did not correlate with self-reported metrics of injury (i.e., fight diary). In contrast, HC did not exhibit significant longitudinal changes over a 4-month follow-up period (p \> 0.05). Collectively, current results provide preliminary evidence of progressive changes in brain chemistry and structure over a relatively short time period in individuals with high exposure to repetitive head hits. These findings require replication in independent samples. © Mary Ann Liebert, Inc. 2015.},
keywords = {Adolescent, adult, Article, biological marker, Biomarkers, BRAIN chemistry, brain concussion, brain cortex, brain size, Cerebral Cortex, CHOLINE, clinical article, cognition, Concussion, controlled study, cortical thickness (brain), creatine, executive function, Female, follow up, Follow-Up Studies, frontal gyrus, glutamic acid, glutamine, human, Humans, Injuries, inositol, Longitudinal, Longitudinal studies, longitudinal study, Magnetic Resonance Imaging, Male, martial art, Martial Arts, Memory, middle aged, mixed martial art, n acetylaspartic acid, neuropsychological test, Neuropsychological Tests, nuclear magnetic resonance imaging, NUCLEAR magnetic resonance spectroscopy, occipital cortex, pathology, posterior cingulate, psychology, repetitive injury, Spectroscopy, volumetrics, white matter, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Lefebvre, G; Tremblay, S; Théoret, H
Probing the effects of mild traumatic brain injury with transcranial magnetic stimulation of the primary motor cortex Journal Article
In: Brain Injury, vol. 29, no. 9, pp. 1032–1043, 2015.
@article{Lefebvre2015,
title = {Probing the effects of mild traumatic brain injury with transcranial magnetic stimulation of the primary motor cortex},
author = {Lefebvre, G and Tremblay, S and Th\'{e}oret, H},
doi = {10.3109/02699052.2015.1028447},
year = {2015},
date = {2015-01-01},
journal = {Brain Injury},
volume = {29},
number = {9},
pages = {1032--1043},
abstract = {Primary objective: The present paper systematically reviews studies using transcranial magnetic stimulation (TMS) over the primary motor cortex (M1) to assess cortical excitability, intra-cortical inhibition/facilitation and synaptic plasticity following mild traumatic brain injury (mTBI).Methods: Articles using TMS over M1 in patients with mTBI or sport-related concussion indexed in PubMed and published between 1998 and September 2014 were included in the present review.Main outcomes and results: From the 17 articles that matched search criteria, results from various TMS paradigms were summarized and divided in three main areas of interest: motor cortical excitability/facilitation, motor cortical inhibition and cortical plasticity. Although studies suggest a trend of abnormal intra-cortical inhibition following mTBI, no clear and specific pattern emerges from the surveyed data.Conclusions: At this time and with the possible exception of intra-cortical inhibitory measures, TMS cannot reliably detect changes in M1 excitability in individuals with mTBI or a concussion at both the acute and chronic stages of injury. This may be explained by the small number of studies and large variety of stimulation parameters. Additional longitudinal and multimodal studies are needed to better understand the nature of the excitability changes that may occur within M1 following mTBI. © 2015 Taylor \& Francis Group, LLC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Mayer, A R; Ling, J M; Dodd, A B; Gasparovic, C; Klimaj, S D; Meier, T B
A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters Journal Article
In: Journal of Neurotrauma, vol. 32, no. 22, pp. 1759–1767, 2015.
@article{Mayer2015b,
title = {A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters},
author = {Mayer, A R and Ling, J M and Dodd, A B and Gasparovic, C and Klimaj, S D and Meier, T B},
doi = {10.1089/neu.2014.3833},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
number = {22},
pages = {1759--1767},
abstract = {Growing evidence suggests that temporally proximal acute concussions and repetitive subconcussive head injuries may lead to long-term neurological deficits. However, the underlying mechanisms of injury and their relative time-scales are not well documented in human injury models. The current study therefore investigated whether biomarkers of brain chemistry (magnetic resonance [MR] spectroscopy: N-acetylaspartate [NAA], combined glutamate and glutamine [Glx], total creatine [Cre], choline compounds [Cho], and myo-inositol [mI]) and structure (cortical thickness, white matter [WM]/subcortical volume) differed between mixed martial artists (MMA; n = 13) and matched healthy controls (HC) without a history of contact sport participation (HC; n = 14). A subset of participants (MMA = 9; HC = 10) returned for follow-up visits, with MMA (n = 3) with clinician-documented acute concussions also scanned serially. As expected, MMA self-reported a higher incidence of previous concussions and significantly more cognitive symptoms during prior concussion recovery. Fighters also exhibited reduced memory and processing speed relative to controls on neuropsychological testing coupled with cortical thinning in the left posterior cingulate gyrus and right occipital cortex at baseline assessment. Over a 1-year follow-up period, MMA experienced a significant decrease in both WM volume and NAA concentration, as well as relative thinning in the left middle and superior frontal gyri. These longitudinal changes did not correlate with self-reported metrics of injury (i.e., fight diary). In contrast, HC did not exhibit significant longitudinal changes over a 4-month follow-up period (p \> 0.05). Collectively, current results provide preliminary evidence of progressive changes in brain chemistry and structure over a relatively short time period in individuals with high exposure to repetitive head hits. These findings require replication in independent samples. © Mary Ann Liebert, Inc. 2015.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lefebvre, G; Tremblay, S; Théoret, H
Probing the effects of mild traumatic brain injury with transcranial magnetic stimulation of the primary motor cortex Journal Article
In: Brain Injury, vol. 29, no. 9, pp. 1032–1043, 2015.
Abstract | Links | BibTeX | Tags: 4 aminobutyric acid B receptor, adult, aged, Article, brain concussion, brain cortex, Brain Injuries, central motor conduction time, clinical assessment, Concussion, cortical excitability, electrostimulation, evoked muscle response, Evoked Potentials, Female, human, Humans, Inhibition, latent inhibition, latent period, long interval intracortical inhibition, magnetic stimulation, Male, Medline, middle aged, Motor, motor cortex, motor evoked potential, motor nerve conduction, muscle contraction, nerve cell excitability, nerve cell plasticity, neuromuscular facilitation, Neuronal Plasticity, outcome assessment, paired associative stimulation, Pathophysiology, PHYSIOLOGY, postsynaptic inhibition, primary motor cortex, procedures, short interval intracortical inhibition, short latency afferent inhibition, sport injury, stimulus response, Systematic Review, therapy effect, theta burst stimulation, TRANSCRANIAL magnetic stimulation, traumatic brain injury, Young Adult
@article{Lefebvre2015,
title = {Probing the effects of mild traumatic brain injury with transcranial magnetic stimulation of the primary motor cortex},
author = {Lefebvre, G and Tremblay, S and Th\'{e}oret, H},
doi = {10.3109/02699052.2015.1028447},
year = {2015},
date = {2015-01-01},
journal = {Brain Injury},
volume = {29},
number = {9},
pages = {1032--1043},
abstract = {Primary objective: The present paper systematically reviews studies using transcranial magnetic stimulation (TMS) over the primary motor cortex (M1) to assess cortical excitability, intra-cortical inhibition/facilitation and synaptic plasticity following mild traumatic brain injury (mTBI).Methods: Articles using TMS over M1 in patients with mTBI or sport-related concussion indexed in PubMed and published between 1998 and September 2014 were included in the present review.Main outcomes and results: From the 17 articles that matched search criteria, results from various TMS paradigms were summarized and divided in three main areas of interest: motor cortical excitability/facilitation, motor cortical inhibition and cortical plasticity. Although studies suggest a trend of abnormal intra-cortical inhibition following mTBI, no clear and specific pattern emerges from the surveyed data.Conclusions: At this time and with the possible exception of intra-cortical inhibitory measures, TMS cannot reliably detect changes in M1 excitability in individuals with mTBI or a concussion at both the acute and chronic stages of injury. This may be explained by the small number of studies and large variety of stimulation parameters. Additional longitudinal and multimodal studies are needed to better understand the nature of the excitability changes that may occur within M1 following mTBI. © 2015 Taylor \& Francis Group, LLC.},
keywords = {4 aminobutyric acid B receptor, adult, aged, Article, brain concussion, brain cortex, Brain Injuries, central motor conduction time, clinical assessment, Concussion, cortical excitability, electrostimulation, evoked muscle response, Evoked Potentials, Female, human, Humans, Inhibition, latent inhibition, latent period, long interval intracortical inhibition, magnetic stimulation, Male, Medline, middle aged, Motor, motor cortex, motor evoked potential, motor nerve conduction, muscle contraction, nerve cell excitability, nerve cell plasticity, neuromuscular facilitation, Neuronal Plasticity, outcome assessment, paired associative stimulation, Pathophysiology, PHYSIOLOGY, postsynaptic inhibition, primary motor cortex, procedures, short interval intracortical inhibition, short latency afferent inhibition, sport injury, stimulus response, Systematic Review, therapy effect, theta burst stimulation, TRANSCRANIAL magnetic stimulation, traumatic brain injury, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Mayer, A R; Ling, J M; Dodd, A B; Gasparovic, C; Klimaj, S D; Meier, T B
A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters Journal Article
In: Journal of Neurotrauma, vol. 32, no. 22, pp. 1759–1767, 2015.
Abstract | Links | BibTeX | Tags: Adolescent, adult, Article, biological marker, Biomarkers, BRAIN chemistry, brain concussion, brain cortex, brain size, Cerebral Cortex, CHOLINE, clinical article, cognition, Concussion, controlled study, cortical thickness (brain), creatine, executive function, Female, follow up, Follow-Up Studies, frontal gyrus, glutamic acid, glutamine, human, Humans, Injuries, inositol, Longitudinal, Longitudinal studies, longitudinal study, Magnetic Resonance Imaging, Male, martial art, Martial Arts, Memory, middle aged, mixed martial art, n acetylaspartic acid, neuropsychological test, Neuropsychological Tests, nuclear magnetic resonance imaging, NUCLEAR magnetic resonance spectroscopy, occipital cortex, pathology, posterior cingulate, psychology, repetitive injury, Spectroscopy, volumetrics, white matter, Young Adult
@article{Mayer2015b,
title = {A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters},
author = {Mayer, A R and Ling, J M and Dodd, A B and Gasparovic, C and Klimaj, S D and Meier, T B},
doi = {10.1089/neu.2014.3833},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
number = {22},
pages = {1759--1767},
abstract = {Growing evidence suggests that temporally proximal acute concussions and repetitive subconcussive head injuries may lead to long-term neurological deficits. However, the underlying mechanisms of injury and their relative time-scales are not well documented in human injury models. The current study therefore investigated whether biomarkers of brain chemistry (magnetic resonance [MR] spectroscopy: N-acetylaspartate [NAA], combined glutamate and glutamine [Glx], total creatine [Cre], choline compounds [Cho], and myo-inositol [mI]) and structure (cortical thickness, white matter [WM]/subcortical volume) differed between mixed martial artists (MMA; n = 13) and matched healthy controls (HC) without a history of contact sport participation (HC; n = 14). A subset of participants (MMA = 9; HC = 10) returned for follow-up visits, with MMA (n = 3) with clinician-documented acute concussions also scanned serially. As expected, MMA self-reported a higher incidence of previous concussions and significantly more cognitive symptoms during prior concussion recovery. Fighters also exhibited reduced memory and processing speed relative to controls on neuropsychological testing coupled with cortical thinning in the left posterior cingulate gyrus and right occipital cortex at baseline assessment. Over a 1-year follow-up period, MMA experienced a significant decrease in both WM volume and NAA concentration, as well as relative thinning in the left middle and superior frontal gyri. These longitudinal changes did not correlate with self-reported metrics of injury (i.e., fight diary). In contrast, HC did not exhibit significant longitudinal changes over a 4-month follow-up period (p \> 0.05). Collectively, current results provide preliminary evidence of progressive changes in brain chemistry and structure over a relatively short time period in individuals with high exposure to repetitive head hits. These findings require replication in independent samples. © Mary Ann Liebert, Inc. 2015.},
keywords = {Adolescent, adult, Article, biological marker, Biomarkers, BRAIN chemistry, brain concussion, brain cortex, brain size, Cerebral Cortex, CHOLINE, clinical article, cognition, Concussion, controlled study, cortical thickness (brain), creatine, executive function, Female, follow up, Follow-Up Studies, frontal gyrus, glutamic acid, glutamine, human, Humans, Injuries, inositol, Longitudinal, Longitudinal studies, longitudinal study, Magnetic Resonance Imaging, Male, martial art, Martial Arts, Memory, middle aged, mixed martial art, n acetylaspartic acid, neuropsychological test, Neuropsychological Tests, nuclear magnetic resonance imaging, NUCLEAR magnetic resonance spectroscopy, occipital cortex, pathology, posterior cingulate, psychology, repetitive injury, Spectroscopy, volumetrics, white matter, Young Adult},
pubstate = {published},
tppubtype = {article}
}