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Journal of Clinical Neurophysiology :... Mar 2018Electrical stimulation mapping (ESM) of the brain remains a major procedure for guiding epilepsy and tumor surgeries. This article collates available experiences and... (Review)
Review
Electrical stimulation mapping (ESM) of the brain remains a major procedure for guiding epilepsy and tumor surgeries. This article collates available experiences and data in ESM to develop a guide for conducting the procedure. There are many factors that influence the yield of ESM. The stimulation parameters offered in this article need to be adjusted within safe limits to address the factors. Each ESM procedure should be tailored to the patient's age and baseline mental or psychological capacity. Stimulation-induced seizures and EEG afterdischarges disrupt ESM procedure and render the interpretation of the results difficult. There are specific measures that can lessen the risk of seizures and afterdischarges during ESM. Electrical stimulation mapping procedure requires several tasks on the part of those conducting the procedure, such as operating the stimulator and the EEG recording equipment, administering behavioral or language tests and observing both patient and EEG responses to the stimulation. A team of experienced staff is necessary for individual assumption of each task. Knowledge of the spatial relationship between electrode contacts and underlying normal or abnormal brain structures is essential for interpreting ESM results. When testing for motor or sensory response, be aware of the distinction between responses at the primary motor area and responses at the supplementary sensorimotor area. The anatomy of supplementary sensorimotor area is more variable and functional than it is fixed and structural, although its general confines and somatotopic organization are known. In addition, negative motor responses to stimulation must be recognized to avoid misinterpretation of ESM results, especially in language mapping.
Topics: Brain Mapping; Brain Waves; Cerebral Cortex; Electric Stimulation; Electroencephalography; Guidelines as Topic; Humans
PubMed: 29499016
DOI: 10.1097/WNP.0000000000000435 -
Methods (San Diego, Calif.) Aug 2008Brain mapping in the freely moving animal is useful for studying motor circuits, not only because it avoids the potential confound of sedation or restraints, but because... (Review)
Review
Brain mapping in the freely moving animal is useful for studying motor circuits, not only because it avoids the potential confound of sedation or restraints, but because activated brain states may serve to accentuate differences that only manifest partially while a subject is in the resting state. Perfusion or metabolic mapping using autoradiography allows one to examine changes in brain function at the circuit level across the entire brain with a spatial resolution (approximately 100 micro) appropriate for the rat or mouse brain, and a temporal resolution (seconds-minutes) sufficient for capturing acute brain changes. Here we summarize the application of these methods to the functional brain mapping of behaviors involving locomotion of small animals, methods for the three-dimensional reconstruction of the brain from autoradiographic sections, voxel based analysis of the whole brain, and generation of maps of the flattened rat cortex. Application of these methods in animal models promises utility in improving our understanding of motor function in the normal brain, and of the effects of neuropathology and treatment interventions such as exercise have on the reorganization of motor circuits.
Topics: Animals; Brain; Brain Mapping; Mice; Models, Animal; Motor Activity; Rats
PubMed: 18554522
DOI: 10.1016/j.ymeth.2008.04.006 -
Neurosurgery Clinics of North America Apr 2011Functional magnetic resonance imaging (fMRI) enhances the understanding of neuroanatomy and functions of the brain and is becoming an accepted brain-mapping tool for... (Review)
Review
Functional magnetic resonance imaging (fMRI) enhances the understanding of neuroanatomy and functions of the brain and is becoming an accepted brain-mapping tool for clinicians, researchers, and basic scientists alike. A noninvasive procedure with no known risks, fMRI has an ever-growing list of clinical applications, including presurgical mapping of motor, language, and memory functions. fMRI benefits patients and allows neurosurgeons to be aware of, and to navigate, the precise location of patient-specific eloquent cortices and structural anomalies from a tumor. Optimizing preoperative fMRI requires tailoring the fMRI paradigm to the patient's clinical situation and understanding the pitfalls of fMRI interpretation.
Topics: Artifacts; Brain Mapping; Electroencephalography; Humans; Magnetic Resonance Imaging; Magnetoencephalography; Motor Neurons; Neuronal Plasticity; Neuronavigation; Neurosurgical Procedures; Oxygen; Sensory Receptor Cells
PubMed: 21435572
DOI: 10.1016/j.nec.2010.11.003 -
BioTechniques Apr 2013
Topics: Brain; Brain Mapping; Genome; History, 20th Century; History, 21st Century; Human Genome Project; Humans
PubMed: 23710523
DOI: 10.2144/000114003 -
Handbook of Clinical Neurology 2019High-resolution EEG recording has become standard in many experimental studies on human brain function and has found its place in the routine presurgical workup of... (Review)
Review
High-resolution EEG recording has become standard in many experimental studies on human brain function and has found its place in the routine presurgical workup of patients with focal epilepsy in several clinical centers. The main aim of high-resolution EEG is source localization with methods that have become increasingly robust and precise. However, high-resolution EEG also allows a spatial analysis of EEG and evoked potentials on the scalp level, thereby identifying topographic features of the scalp potential field. Their value in understanding the dynamics of large-scale networks of the human brain and as markers for neuropsychiatric diseases has been increasingly demonstrated. This chapter discusses the advantages and limitations of such spatial analysis methods and the information that can be gained from them. It also shows that the spatial frequency of the scalp potential field is higher than previously assumed and discusses the consequences regarding the number of channels required to properly capture these spatial frequencies.
Topics: Brain; Brain Mapping; Electrodes; Electroencephalography; Humans
PubMed: 31277847
DOI: 10.1016/B978-0-444-64032-1.00012-6 -
Brain : a Journal of Neurology Jul 2012
Topics: Brain Mapping; Consciousness; Humans; Morals
PubMed: 22734129
DOI: 10.1093/brain/aws167 -
Nature Sep 2016
Topics: Animals; Brain Mapping; Congresses as Topic; Goals; Humans; Information Dissemination; International Cooperation; Models, Animal; Neurosciences; New York City
PubMed: 27680917
DOI: 10.1038/nature.2016.20658 -
Annales Francaises D'anesthesie Et de... Jun 2012Brain tumor surgery is at risk when lesions are located in eloquent areas. The interindividual anatomo-functional variability of the central nervous system implies that... (Review)
Review
Brain tumor surgery is at risk when lesions are located in eloquent areas. The interindividual anatomo-functional variability of the central nervous system implies that brain surgery within eloquent regions may induce neurological sequelae. Brain mapping using intraoperative direct electrical stimulation in awake patients has been for long validated as the standard for functional brain mapping. Direct electrical stimulation inducing a local transient electrical and functional disorganization is considered positive if the task performed by the patient is disturbed. The brain area stimulated is then considered as essential for the function tested. However, the exactitude of the information provided by this technique is cautious because the actual impact of cortical direct electrical stimulation is not known. Indeed, the possibility of false negative (insufficient intensity of the stimulation due to the heterogeneity of excitability threshold of different cortical areas) or false positive (current spread, interregional signal propagation responsible for remote effects, which make difficult the interpretation of positive or negative behavioural effects) constitute a limitation of this technique. To improve the sensitivity and specificity of this technique, we used an electrocorticographic recording system allowing a real time visualization of the local. We provide here evidence that direct cortical stimulation combined with electrocorticographic recording could be useful to detect remote after discharge and to adjust stimulation parameters. In addition this technique offers new perspective to better assess connectivity of cerebral networks.
Topics: Brain; Brain Mapping; Brain Neoplasms; Electric Stimulation; Electroencephalography; Humans; Neurosurgery; Neurosurgical Procedures; Preoperative Care; Wakefulness
PubMed: 22683402
DOI: 10.1016/j.annfar.2012.04.010 -
PLoS Computational Biology Sep 2021A number of neuroimaging techniques have been employed to understand how visual information is transformed along the visual pathway. Although each technique has spatial...
A number of neuroimaging techniques have been employed to understand how visual information is transformed along the visual pathway. Although each technique has spatial and temporal limitations, they can each provide important insights into the visual code. While the BOLD signal of fMRI can be quite informative, the visual code is not static and this can be obscured by fMRI's poor temporal resolution. In this study, we leveraged the high temporal resolution of EEG to develop an encoding technique based on the distribution of responses generated by a population of real-world scenes. This approach maps neural signals to each pixel within a given image and reveals location-specific transformations of the visual code, providing a spatiotemporal signature for the image at each electrode. Our analyses of the mapping results revealed that scenes undergo a series of nonuniform transformations that prioritize different spatial frequencies at different regions of scenes over time. This mapping technique offers a potential avenue for future studies to explore how dynamic feedforward and recurrent processes inform and refine high-level representations of our visual world.
Topics: Adolescent; Brain Mapping; Computational Biology; Electrodes; Electroencephalography; Female; Functional Neuroimaging; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Photic Stimulation; Spatio-Temporal Analysis; Visual Cortex; Visual Pathways; Young Adult
PubMed: 34570753
DOI: 10.1371/journal.pcbi.1009456 -
Methods (San Diego, Calif.) Feb 2015The Allen Mouse Brain Connectivity Atlas is a mesoscale whole brain axonal projection atlas of the C57Bl/6J mouse brain. Anatomical trajectories throughout the brain... (Review)
Review
The Allen Mouse Brain Connectivity Atlas is a mesoscale whole brain axonal projection atlas of the C57Bl/6J mouse brain. Anatomical trajectories throughout the brain were mapped into a common 3D space using a standardized platform to generate a comprehensive and quantitative database of inter-areal and cell-type-specific projections. This connectivity atlas has several desirable features, including brain-wide coverage, validated and versatile experimental techniques, a single standardized data format, a quantifiable and integrated neuroinformatics resource, and an open-access public online database (http://connectivity.brain-map.org/). Meaningful informatics data quantification and comparison is key to effective use and interpretation of connectome data. This relies on successful definition of a high fidelity atlas template and framework, mapping precision of raw data sets into the 3D reference framework, accurate signal detection and quantitative connection strength algorithms, and effective presentation in an integrated online application. Here we describe key informatics pipeline steps in the creation of the Allen Mouse Brain Connectivity Atlas and include basic application use cases.
Topics: Animals; Atlases as Topic; Brain; Brain Mapping; Humans; Informatics; Mice; Mice, Inbred C57BL
PubMed: 25536338
DOI: 10.1016/j.ymeth.2014.12.013