scholarly journals Abnormal Motor Response Associated With Concussive Injuries: Biomechanical Comparison Between Impact Seizures and Loss of Consciousness

2019 ◽  
Vol 54 (7) ◽  
pp. 765-771 ◽  
Author(s):  
Janie Cournoyer ◽  
T. Blaine Hoshizaki
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Corpus Callosum ◽  
Impact Velocity ◽  
American Football ◽  
Loss Of Consciousness ◽  
Rotational Acceleration ◽  
Velocity Peak ◽  
The Impact ◽  
Concussive Injuries

Context Loss of consciousness (LOC) and impact seizures associated with concussion represent different clinical presentations of concussion; however, they are often investigated and treated similarly. The biomechanical parameters differentiating these 2 distinct signs of injury are poorly described. Objective To differentiate between cases of concussions with LOC and those with impact seizures by comparing the impact velocity, peak linear and peak rotational acceleration, as well as brain tissue deformation in the cerebral cortex, white matter, brainstem, cerebellum, thalamus, and corpus callosum. Design Descriptive laboratory study. Patients or Other Participants Elite American football players who sustained an LOC (n = 20) or impact seizures (n = 21). Main Outcome Measure(s) Impact velocity, peak linear and peak rotational acceleration, maximum principal strain, cumulative strain damage measure at 10%, and strain rate (SR). Results The SR in the cerebral white matter was greater in the LOC group than in the impact-seizure group. Similar trends were observed for SRs in the cerebral cortex, brainstem, and corpus callosum. No differences were present between groups for the other variables in this study. Conclusions A lower SR in certain brain regions helps to explain why motor function is preserved and can be observed in patients with impact seizures versus LOC from concussive injuries.

scholarly journals Biomechanical comparison of concussions with and without a loss of consciousness in elite American football

Neurology ◽  
2018 ◽  
Vol 91 (23 Supplement 1) ◽  
pp. S3.1-S3
Author(s):  
Janie Cournoyer ◽  
Thomas Blaine Hoshizaki
Keyword(s):  
Brain Tissue ◽  
Impact Velocity ◽  
Linear Acceleration ◽  
Brain Regions ◽  
American Football ◽  
Loss Of Consciousness ◽  
Tissue Deformation ◽  
Rotational Acceleration ◽  
Cumulative Strain ◽  
Severity Of Injury

IntroductionLoss of consciousness (LOC) occurs with approximately 8 percent of concussions in professional American football and has been associated with severity of injury (1, 2). However it is unknown how LOC relates to severity of head impact responses. The purpose of this study was to compare the head accelerations and brain tissue deformation between cases of concussions with and without LOC in elite American football to inform prevention strategies.MethodsConcussive injuries with and without LOC from helmet-to-helmet and shoulder collisions as well as falls in elite American football were reconstructed in laboratory using hybrid III headform to obtain peak linear and rotational acceleration and maximum principal strain, cumulative strain damage at 10%, and strain rate metrics in 5 brain regions associated with loss of consciousness.ResultsImpact velocity, peak linear and rotational acceleration were greater in the LOC group than the no LOC group. The brain tissue deformation metrics were greater in the LOC group than the no LOC group. Linear acceleration was most predictive for cases of helmet-to-helmet collisions whereas shoulder collisions were best predicted by rotational acceleration. The best overall predictor was impact velocity.Discussion/conclusionThe presence of a loss of consciousness in concussive impacts is a result of greater magnitude of brain tissue trauma. This was primarily caused by greater impact velocities in head impacts leading to LOC. Rules aiming at mitigating this aspect of the game would decrease the risk of a loss of consciousness in this sport. Each type of events resulted in different values of kinematic data and brain tissue deformation, which suggests that studies evaluating risk of concussions based 1 type of event cannot be generalized.

THE METABOLISM OF NORMAL BRAIN AND HUMAN GLIOMAS IN RELATION TO CELL TYPE AND DENSITY

1955 ◽  
Vol 33 (3) ◽  
pp. 395-403 ◽  
Author(s):  
Irving H. Heller ◽  
K. A. C. Elliott
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Brain Tumors ◽  
Corpus Callosum ◽  
Oxygen Uptake ◽  
Glial Cells ◽  
Cerebellar Cortex ◽  
Unit Weight ◽  
Uptake Rates ◽  
The Brain

Per unit weight, cerebral and cerebellar cortex respire much more actively than corpus callosum. The rate per cell nucleus is highest in cerebral cortex, lower in corpus callosum, and still lower in cerebellar cortex. The oxygen uptake rates of the brain tumors studied, with the exception of an oligodendroglioma, were about the same as that of white matter on the weight basis but lower than that of cerebral cortex or white matter on the cell basis. In agreement with previous work, an oligodendroglioma respired much more actively than the other tumors. The rates of glycolysis of the brain tumors per unit weight were low but, relative to their respiration rate, glycolysis was higher than in normal gray or white matter. Consideration of the figures obtained leads to the following tentative conclusions: Glial cells of corpus callosum respire more actively than the neurons of the cerebellar cortex. Neurons of the cerebral cortex respire on the average much more actively than neurons of the cerebellar cortex or glial cells. Considerably more than 70% of the oxygen uptake by cerebral cortex is due to neurons. The oxygen uptake rates of normal oligodendroglia and astrocytes are probably about the same as the rates found per nucleus in an oligodendroglioma and in astrocytomas; oligodendroglia respire much more actively than astrocytes.

Causal role of group B Streptococcus-induced acute chorioamnionitis in intrauterine growth retardation and cerebral palsy-like impairments

2019 ◽  
Vol 10 (5) ◽  
pp. 595-602
Author(s):  
M.-J. Allard ◽  
M.-E. Brochu ◽  
J. D. Bergeron ◽  
M. Segura ◽  
G. Sébire
Keyword(s):  
Cerebral Palsy ◽  
White Matter ◽  
Corpus Callosum ◽  
Growth Retardation ◽  
Intrauterine Growth Retardation ◽  
Microglial Cells ◽  
Male Rats ◽  
Intrauterine Growth ◽  
Group B ◽  
The Impact

AbstractChorioamnionitis and intrauterine growth retardation (IUGR) are risk factors for cerebral palsy (CP). Common bacteria isolated in chorioamnionitis include group B Streptococcus (GBS) serotypes Ia and III. Little is known about the impact of placental inflammation induced by different bacteria, including different GBS strains. We aimed to test the impact of chorioamnionitis induced by two common GBS serotypes (GBSIa and GBSIII) on growth and neuromotor outcomes in the progeny. Dams were exposed at the end of gestation to either saline, inactivated GBSIa or GBSIII. Inactivated GBS bacteria invaded placentas and triggered a chorioamnionitis featured by massive polymorphonuclear cell infiltrations. Offspring exposed to GBSIII – but not to GBSIa – developed IUGR, persisting beyond adolescent age. Male rats in utero exposed to GBSIII traveled a lower distance in the Open Field test, which was correlating with their level of IUGR. GBSIII-exposed rats presented decreased startle responses to acoustic stimuli beyond adolescent age. GBS-exposed rats displayed a dysmyelinated white matter in the corpus callosum adjacent to thinner primary motor cortices. A decreased density of microglial cells was detected in the mature corpus callosum of GBSIII-exposed males – but not females – which was correlating positively with the primary motor cortex thickness. Altogether, our results demonstrate a causal link between pathogen-induced acute chorioamnionitis and (1) IUGR, (2) serotype- and sex-specific neuromotor impairments and (3) abnormal development of primary motor cortices, dysmyelinated white matter and decreased density of microglial cells.

scholarly journals Changes in white matter in mice resulting from low-frequency brain stimulation

2018 ◽  
Vol 115 (27) ◽  
pp. E6339-E6346 ◽  
Author(s):  
Denise M. Piscopo ◽  
Aldis P. Weible ◽  
Mary K. Rothbart ◽  
Michael I. Posner ◽  
Cristopher M. Niell
Keyword(s):  
White Matter ◽  
Corpus Callosum ◽  
Anterior Cingulate Cortex ◽  
Low Frequency ◽  
Cingulate Cortex ◽  
Subcortical White Matter ◽  
Cellular Level ◽  
Anterior Cingulate ◽  
G Ratio ◽  
The Impact

Recent reports have begun to elucidate mechanisms by which learning and experience produce white matter changes in the brain. We previously reported changes in white matter surrounding the anterior cingulate cortex in humans after 2–4 weeks of meditation training. We further found that low-frequency optogenetic stimulation of the anterior cingulate in mice increased time spent in the light in a light/dark box paradigm, suggesting decreased anxiety similar to what is observed following meditation training. Here, we investigated the impact of this stimulation at the cellular level. We found that laser stimulation in the range of 1–8 Hz results in changes to subcortical white matter projection fibers in the corpus callosum. Specifically, stimulation resulted in increased oligodendrocyte proliferation, accompanied by a decrease in the g-ratio within the corpus callosum underlying the anterior cingulate cortex. These results suggest that low-frequency stimulation can result in activity-dependent remodeling of myelin, giving rise to enhanced connectivity and altered behavior.

scholarly journals Quantitative assessment of prefrontal cortex in humans relative to nonhuman primates

2018 ◽  
Vol 115 (22) ◽  
pp. E5183-E5192 ◽  
Author(s):  
Chad J. Donahue ◽  
Matthew F. Glasser ◽  
Todd M. Preuss ◽  
James K. Rilling ◽  
David C. Van Essen
Keyword(s):  
Cerebral Cortex ◽  
Prefrontal Cortex ◽  
White Matter ◽  
Corpus Callosum ◽  
Quantitative Assessment ◽  
Nonhuman Primates ◽  
Subcortical White Matter ◽  
Association Cortex ◽  
Cortical Gray Matter ◽  
And Function

Humans have the largest cerebral cortex among primates. The question of whether association cortex, particularly prefrontal cortex (PFC), is disproportionately larger in humans compared with nonhuman primates is controversial: Some studies report that human PFC is relatively larger, whereas others report a more uniform PFC scaling. We address this controversy using MRI-derived cortical surfaces of many individual humans, chimpanzees, and macaques. We present two parcellation-based PFC delineations based on cytoarchitecture and function and show that a previously used morphological surrogate (cortex anterior to the genu of the corpus callosum) substantially underestimates PFC extent, especially in humans. We find that the proportion of cortical gray matter occupied by PFC in humans is up to 1.9-fold greater than in macaques and 1.2-fold greater than in chimpanzees. The disparity is even more prominent for the proportion of subcortical white matter underlying the PFC, which is 2.4-fold greater in humans than in macaques and 1.7-fold greater than in chimpanzees.

A Cross-Sectional Study on the Impact of Arterial Stiffness on the Corpus Callosum, a Key White Matter Tract Implicated in Alzheimer’s Disease

2020 ◽  
Vol 77 (2) ◽  
pp. 591-605
Author(s):  
Atef Badji ◽  
Adrián Noriega de la Colina ◽  
Tommy Boshkovski ◽  
Dalia Sabra ◽  
Agah Karakuzu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Older Adults ◽  
Alzheimer's Disease ◽  
White Matter ◽  
Arterial Stiffness ◽  
Corpus Callosum ◽  
Water Diffusion ◽  
The Body ◽  
Extracellular Water ◽  
The Impact

Background: Vascular risk factors such as arterial stiffness play an important role in the etiology of Alzheimer’s disease (AD), presumably due to the emergence of white matter lesions. However, the impact of arterial stiffness to white matter structure involved in the etiology of AD, including the corpus callosum remains poorly understood. Objective: The aims of the study are to better understand the relationship between arterial stiffness, white matter microstructure, and perfusion of the corpus callosum in older adults. Methods: Arterial stiffness was estimated using the gold standard measure of carotid-femoral pulse wave velocity (cfPWV). Cognitive performance was evaluated with the Trail Making Test part B-A. Neurite orientation dispersion and density imaging was used to obtain microstructural information such as neurite density and extracellular water diffusion. The cerebral blood flow was estimated using arterial spin labelling. Results: cfPWV better predicts the microstructural integrity of the corpus callosum when compared with other index of vascular aging (the augmentation index, the systolic blood pressure, and the pulse pressure). In particular, significant associations were found between the cfPWV, an alteration of the extracellular water diffusion, and a neuronal density increase in the body of the corpus callosum which was also correlated with the performance in cognitive flexibility. Conclusion: Our results suggest that arterial stiffness is associated with an alteration of brain integrity which impacts cognitive function in older adults.

THE METABOLISM OF NORMAL BRAIN AND HUMAN GLIOMAS IN RELATION TO CELL TYPE AND DENSITY

1955 ◽  
Vol 33 (1) ◽  
pp. 395-403 ◽  
Author(s):  
Irving H. Heller ◽  
K. A. C. Elliott
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Brain Tumors ◽  
Corpus Callosum ◽  
Oxygen Uptake ◽  
Glial Cells ◽  
Cerebellar Cortex ◽  
Unit Weight ◽  
Uptake Rates ◽  
The Brain

Per unit weight, cerebral and cerebellar cortex respire much more actively than corpus callosum. The rate per cell nucleus is highest in cerebral cortex, lower in corpus callosum, and still lower in cerebellar cortex. The oxygen uptake rates of the brain tumors studied, with the exception of an oligodendroglioma, were about the same as that of white matter on the weight basis but lower than that of cerebral cortex or white matter on the cell basis. In agreement with previous work, an oligodendroglioma respired much more actively than the other tumors. The rates of glycolysis of the brain tumors per unit weight were low but, relative to their respiration rate, glycolysis was higher than in normal gray or white matter. Consideration of the figures obtained leads to the following tentative conclusions: Glial cells of corpus callosum respire more actively than the neurons of the cerebellar cortex. Neurons of the cerebral cortex respire on the average much more actively than neurons of the cerebellar cortex or glial cells. Considerably more than 70% of the oxygen uptake by cerebral cortex is due to neurons. The oxygen uptake rates of normal oligodendroglia and astrocytes are probably about the same as the rates found per nucleus in an oligodendroglioma and in astrocytomas; oligodendroglia respire much more actively than astrocytes.

Cognitive dysfunctions associated with white matter damage due to cardiovascular burden – determinants and interpretations

2014 ◽  
Vol 45 (3) ◽  
pp. 334-345 ◽  
Author(s):  
Paweł Krukow
Keyword(s):  
Cerebral Cortex ◽  
White Matter ◽  
Cardiovascular Diseases ◽  
Cognitive Disorder ◽  
Theoretical Background ◽  
Dynamic Aspect ◽  
Pathological Changes ◽  
White Matter Damage ◽  
Neuropsychological Disorders ◽  
Considerable Research

AbstractAlthough considerable research has been devoted to cognitive functions deteriorating due to diseases of cardiovascular system, rather less attention has been paid to their theoretical background. Progressive vascular disorders as hypertension, atherosclerosis and carotid artery stenosis generate most of all pathological changes in the white matter, that cause specific cognitive disorder: disconnection syndromes, and disturbances in the dynamic aspect of information processing. These features made neuropsychological disorders secondary to cardiovascular diseases different than the effects of cerebral cortex damage, which may be interpreted modularly.

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