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Cerebral Fractional Anisotropy Score in Trauma Patients: A New Indicator of White Matter Injury After Trauma
Abstract
Previous studies evaluating quantitative cerebral white matter diffusion anisotropy indexes have shown alteration in patients after trauma. To date, no clinically applicable scale exists by which to gauge and test the relevance of these findings. We propose the cerebral fractional anisotropy score in trauma (C-FAST) as an index of white matter injury, and we correlate C-FAST with several predictor and outcome variables.
Fifteen patients were randomly selected from the trauma surgery service. Thirty control patients were randomly selected from the emergency department. All patients were subjected to MRI evaluation, including a diffusion-weighted sequence. Data extracted from the record of each subject included Glasgow Coma Scale, revised trauma score, Abbreviated Injury Scale, initial head CT results, patient disposition, length of hospital stay, and length of stay in intensive care unit. Region of interest measurements were made in fractional anisotropy maps in each of 12 white matter regions. Univariate statistics and a two-tailed t test were performed on the raw fractional anisotropy data. Data were then dichotomized using thresholds from univariate statistics. A C-FAST score was devised from the dichotomized data. Logistic regression analyses were performed among the C-FAST, outcome, and predictor data.
Good correlation was noted between the C-FAST and death, hospital stay greater than 10 days, and intensive care unit stay greater than 5 days. Correlation with discharge to rehabilitation facility was good when adjusted for age and sex. Glasgow Coma Scale, revised trauma score, and Abbreviated Injury Scale show good correlation as predictors of a critical C-FAST.
The C-FAST is a promising index derived from MRI diffusion fractional anisotropy measurements that shows successful correlation with outcome and predictor variables. A larger investigation is needed to verify the validity and stability of the correlations.
... The pathology of DAI following TBI is characterized by widespread damage to axons in the brainstem, parasagittal white matter of the cerebral cortex, and corpus callosum (CC) (4)(5)(6)(7)(8)(9). The most frequent sites of DAI are in the CC, particularly the splenium, hemispheric white matter, brainstem, and cerebellum, especially in more severe injuries (6,(10)(11)(12). ...
... With regard to measurement of DAI, DTI has demonstrated potential for improving detection of brain injury (10,11,13,(18)(19)(20)(21). Specifically, individual participants can be compared by calculating a mean FA value across each voxel in their DTI scan. ...
Purpose of the study:
To investigate the association among global and regional white matter fractional anisotropy (FA) values following traumatic brain injury (TBI) and cognitive functioning.
Materials and methods:
This research was conducted in an urban rehabilitation hospital. Participants included adults who were healthy controls (n = 18) or who had a TBI (n = 27). Diffusion tensor imaging using a Siemens VERIO 3T scanner and calculation of global and regional FA values were undertaken. FA values were correlated with neuropsychological test scores and injury severity variables. Logistic regression and receiver operating characteristic (ROC) curve analysis were used to investigate discriminative ability of the FA values. Neuropsychological measures, including the Symbol Digit Modalities Test (SDMT), Trail Making Test, Wechsler Test of Adult Reading, California Verbal Learning Test 2nd Edition, Digit Vigilance Test, and Wisconsin Card Sorting Test, comprised the cognitive measures.
Results:
Within the TBI group, regional FA values were significantly lower across regions compared with controls; global FA and five brain regions were associated with SDMT scores. The FA value within the body of the corpus callosum (CC) yielded excellent discrimination between groups.
Conclusions:
Convergent findings support the discriminability and potential clinical utility of the CC body FA value in the context of TBI.
... These types of collision entail a rapid acceleration-deceleration movement of the head resulting in a typical pattern of damage, characterized by (i) a compression of the brain at the site of the impact (called coup), (ii) a second bruise on the opposite side (contrecoup), and (iii) DAI due to the shearing and tearing of axons either sagitally or laterally, with the latter direction being associated with more severe deficits [22,41,52]. Diffusion tensor imaging (DTI [54][55][56][57]) may uncover these latter white matter damages, which are otherwise typically elusive in routine instrumental analyses partially because of extreme individual variability [54,58]. A major consequence of DAI is that the balance between cortical and subcortical regions may be disrupted, thus causing disconnection syndromes characterized by relatively frequent 2 and highly persistent language deficits [45]. ...
Language- and speech-related disorders are among the most frequent consequences of developmental and acquired pathologies. While classical approaches to the study of these disorders typically employed the lesion method to unveil one-to-one correspondence between locations, the extent of the brain damage, and corresponding symptoms, recent advances advocate the use of online methods of investigation. For example, the use of electrophysiology or magnetoencephalography—especially when combined with anatomical measures—allows for in vivo tracking of real-time language and speech events, and thus represents a particularly promising venue for future research targeting rehabilitative interventions. In this chapter, we provide a comprehensive overview of language and speech pathologies arising from cortical and/or subcortical damage, and their corresponding neurophysiological and pathological symptoms. Building upon the reviewed evidence and literature, we aim at providing a description of how the neurophysiology of the language network changes as a result of brain damage. We will conclude by summarizing the evidence presented in this chapter, while suggesting directions for future research.Key wordsEEGERPsTMSAphasiaParkinson’s diseaseSpecific Language Impairment
... Without a ground truth for diagnosis, classifiers have limited clinical utility unless they can also predict outcomes such as persistent cognitive deficits, symptomatology, and time to return to play. Future studies should build upon the prediction of neuropsychological and morbidity outcomes in varied-severity TBI populations (Hellyer et al., 2013;Ptak et al., 2003) by exploring mTBI classification longitudinally. Further research can also integrate other objective measures, such as validated quantitative electrophysiology-based biomarkers (Bazarian et al., 2021), to optimize classification accuracy. ...
Current methods of concussion assessment lack the objectivity and reliability to detect neurological injury. This multi-site study uses combinations of neuroimaging (diffusion tensor imaging and resting state functional MRI) and cognitive measures to train algorithms to detect the presence of concussion in university athletes. Athletes (29 concussed, 48 controls) completed symptom reports, brief cognitive evaluation, and MRI within 72 h of injury. Hierarchical linear regression compared groups on cognitive and neuroimaging measures while controlling for sex and data collection site. Logistic regression and support vector machine models were trained using cognitive and neuroimaging measures and evaluated for overall accuracy, sensitivity, and specificity. Concussed athletes reported greater symptoms than controls (∆R² = 0.32, p < .001), and performed worse on tests of concentration (∆R² = 0.07, p < .05) and delayed memory (∆R² = 0.17, p < .001). Concussed athletes showed lower functional connectivity within the frontoparietal and primary visual networks (p < .05), but did not differ on mean diffusivity and fractional anisotropy. Of the cognitive measures, classifiers trained using delayed memory yielded the best performance with overall accuracy of 71%, though sensitivity was poor at 46%. Of the neuroimaging measures, classifiers trained using mean diffusivity yielded similar accuracy. Combining cognitive measures with mean diffusivity increased overall accuracy to 74% and sensitivity to 64%, comparable to the sensitivity of symptom report. Trained algorithms incorporating both MRI and cognitive performance variables can reliably detect common neurobiological sequelae of acute concussion. The integration of multi-modal data can serve as an objective, reliable tool in the assessment and diagnosis of concussion.
... Quantitative FA maps may have value in determining the degree of white matter injury. [24][25][26] DWI typically uses echo planar imaging (EPI), a very fast "single-shot" (1 minute) version of a field echo sequence. In general, EPI methods are very sensitive to susceptibility-related geometric distortion and signal loss at bone, air, tissue and metal interfaces (Fig. 11). ...
MRI is a commonly used diagnostic tool in neurology, and all neurologists should possess a working knowledge of imaging fundamentals. An overview of current and impending MRI techniques is presented to help the referring clinician communicate better with the imaging department, understand the utility and limitations of current and emerging technology, improve specificity and appropriateness when ordering MRI studies, and recognize key findings.
... Brain injury is the major contributor to death in multitrauma patients. 1 Motor vehicle accidents are the leading cause of head injuries followed by fall, assault, firearm wounds and others. 2 Computed Tomography (CT) is one of the most comprehensive diagnostic modality of accurate localisation of the site of injury in craniocerebral trauma. ...
Neural oscillations have emerged as a paradigm of reference for EEG and MEG research. In this chapter, we highlight some the possibilities and limits of modelling the dynamics of complex stimulus perception as being shaped by internal oscillators. The reader is introduced to the main physiological tenets underpinning the use of neural oscillations in cognitive neuroscience. The concepts of entrainment and neural tracking are illustrated with particular reference to speech and language processes.Key wordsNeural oscillationsNeural entrainmentCortical trackingSynchronySpeechLanguage
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
Clinical MR Neuroimaging, second edition, provides radiologists, neuroscientists and researchers with a clear understanding of each physiological MR methodology and their applications to the major neurological diseases. Section 1 describes the physical principles underlying each technique and their associated artefacts and pitfalls. Subsequent sections review the application of MRI in a range of clinical disorders: cerebrovascular disease, neoplasia, infection/inflammation/demyelination disorders, seizures, psychiatric/neurodegenerative conditions, and trauma. This new edition includes all recent advances and applications, with greatly increased coverage of permeability imaging, susceptibility imaging, iron imaging, MR spectroscopy and fMRI. All illustrations are completely new, taking advantage of the latest scan capabilities to give images of the highest possible quality. In addition, over 35 new case studies have been included. Editors and contributors are the leading neuroimaging experts worldwide; their unique combination of technical knowledge and clinical expertise makes Clinical MR Neuroimaging the leading text on the subject.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
In two freestanding volumes, Textbook of Neural Repair and Rehabilitation provides comprehensive coverage of the science and practice of neurological rehabilitation. Revised throughout, bringing the book fully up to date, this volume, Medical Neurorehabilitation, can stand alone as a clinical handbook for neurorehabilitation. It covers the practical applications of the basic science principles presented in Volume 1, provides authoritative guidelines on the management of disabling symptoms, and describes comprehensive rehabilitation approaches for the major categories of disabling neurological disorders. New chapters have been added covering genetics in neurorehabilitation, the rehabilitation team and the economics of neurological rehabilitation, and brain stimulation, along with numerous others. Emphasizing the integration of basic and clinical knowledge, this book and its companion are edited and written by leading international authorities. Together they are an essential resource for neuroscientists and provide a foundation of the work of clinical neurorehabilitation professionals.
Clinical MR Neuroimaging, second edition, provides radiologists, neuroscientists and researchers with a clear understanding of each physiological MR methodology and their applications to the major neurological diseases. Section 1 describes the physical principles underlying each technique and their associated artefacts and pitfalls. Subsequent sections review the application of MRI in a range of clinical disorders: cerebrovascular disease, neoplasia, infection/inflammation/demyelination disorders, seizures, psychiatric/neurodegenerative conditions, and trauma. This new edition includes all recent advances and applications, with greatly increased coverage of permeability imaging, susceptibility imaging, iron imaging, MR spectroscopy and fMRI. All illustrations are completely new, taking advantage of the latest scan capabilities to give images of the highest possible quality. In addition, over 35 new case studies have been included. Editors and contributors are the leading neuroimaging experts worldwide; their unique combination of technical knowledge and clinical expertise makes Clinical MR Neuroimaging the leading text on the subject.
There are opportunities for avoiding unnecessary imaging in children who experienced accidental head trauma. This chapter reviews clinical decision rules that can inform when imaging should be performed or can be avoided. Advanced imaging techniques and their current role in the evaluation of pediatric brain injury are also reviewed.
Traumatic brain injury (TBI) is a worldwide source of disability that often affects young adults. For example, in the USA, 1.4 million people are injured every year and approximately 5.3 million individuals currently suffer long-term neurocognitive deficits induced by TBI. Of these new injuries, approximately 80% of them have unremarkable head computed tomography (CT) and routine brain magnetic resonance imaging (MRI).[1] The current lack of definitive imaging findings using conventional neuroimaging techniques makes the objective determination, evaluation, and categorization of TBI fraught with difficulty and leads to disparity between the available subjective measures and clinical outcomes. The current diagnosis of TBI is made on subjective measures of clinical history and neuropsychological testing, with severity classification based on Glasgow Coma Scale, loss of consciousness, and post-traumatic amnesia. Response to therapy or intervention is also based upon these subjective clinical measures. Early objective measures that can determine not only the presence of mild TBI but also more precisely classify the severity of the injury are desirable. Within the current medical imaging armamentarium, the multimodal capability of MRI makes this the most likely and promising candidate to meet these objective neuroimaging goals.
Introduction Dynamic imaging, or tracking, of a "bolus" of intravascularly administered tracer can be interpreted to yield information both from the "first pass," relating primarily to tissue perfusion, or from later "pseudo steady-state" phases, relating to transendothelial transport of the tracer between intravascular and extravascular compartments. Clearly these two processes are intimately related and not trivially resolved by temporal considerations alone. Integrated models of contrast media delivery and equilibration are emerging. Nonetheless, a practical and pragmatic distinction is often drawn between first-pass (perfusion) imaging (0-60 s) and subsequent imaging sensitive to microvascular permeability (typically over a few minutes). Different imaging strategies to track gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) are conventionally chosen: for pseudo steady-state or "permeability" imaging, an imaging sequence sensitive to the T 1 shortening effect of Gd-DTPA is commonly employed, whereas first-pass imaging tends to use an imaging approach sensitive to the magnetic susceptibility effect of the tracer (manifest as transient T 2 shortening). It must, however, be emphasized that this is a practical convention, and both T 2*- and T 1-weighted approaches can be used to study both first pass and subsequent stages of tracer transport; their relative advantages and disadvantages (especially in terms of temporal and spatial resolution) are discussed below. The theory of dynamic contrast-enhanced MRI (DCE-MRI), and derived permeability estimation, is related to the dynamic assessment of signal changes in a tissue voxel fed by an arterial tree and drained by the venous system. Simple kinetic models relate the volume of tracer "out" to be equal to the volume "in" (conservation of matter). Two-compartment models incorporate two environments (capillary and interstitium), the exchange of water between which is governed by rate constraints. A simple exploration of the mathematics reveals how parameters of the microvasculature, namely fractional blood volume (fBV), microvascular permeability and extravascular, extracellular space (EES), can be extracted from a single dynamic scan.
Introduction Magnetic resonance spectroscopy (MRS) provides in vivo information into the metabolic alterations occurring during the different stages of white matter (WM) diseases. Inborn metabolic/genetic disorders are considered here, while the acquired, mainly inflammatory or hypoxic-ischemic conditions, are addressed in Chs. 28, 30, and 48. This chapter describes metabolic characteristics as shown by MRS of WM caused primarily by hereditary conditions (leukodystrophies; Table 52.1). The classification of leukoencephalopathies used here is based on the concept of hypomyelination and demyelination (Table 52.2). Some of these disorders are discussed in Chs. 30 and 53. Several comprehensive reviews on this topic are available. Most publications deal with individual disease entities and will be referred to in the respective sections. Lysosomal disorders Metachromatic leukodystrophy Metachromatic leukodystrophy (MLD, MIM #250100) is an autosomal recessive lysosomal storage disorder caused by mutations in the gene ARSA on chromosome 22q13.31-qter. A deficiency of arylsulfatase A leads to accumulation of cerebroside sulfates in cerebral WM and peripheral nerves.
Clinical MR Neuroimaging, second edition, provides radiologists, neuroscientists and researchers with a clear understanding of each physiological MR methodology and their applications to the major neurological diseases. Section 1 describes the physical principles underlying each technique and their associated artefacts and pitfalls. Subsequent sections review the application of MRI in a range of clinical disorders: cerebrovascular disease, neoplasia, infection/inflammation/demyelination disorders, seizures, psychiatric/neurodegenerative conditions, and trauma. This new edition includes all recent advances and applications, with greatly increased coverage of permeability imaging, susceptibility imaging, iron imaging, MR spectroscopy and fMRI. All illustrations are completely new, taking advantage of the latest scan capabilities to give images of the highest possible quality. In addition, over 35 new case studies have been included. Editors and contributors are the leading neuroimaging experts worldwide; their unique combination of technical knowledge and clinical expertise makes Clinical MR Neuroimaging the leading text on the subject.
Introduction Traumatic brain injury (TBI) is a major public health burden worldwide. It has been described as "a silent epidemic"[1] and as many as 1.5 million people sustain TBI in the USA each year,[2,3] largely attributable to motor vehicle-related accidents, assaults, and falls. Although mortality has decreased over the years through improvements in automotive safety design and acute care of trauma, 80 000 people annually incur long-term disability following TBI, while more than 5.3 million Americans live with long-term disability as a result of TBI. In 1995, total direct and indirect costs of TBI in the USA were estimated by the US Centers for Disease Control and Prevention at $56 billion/year.[4] Improved detection of TBI and prediction of clinical outcome would improve both acute and long-term patient management. Clinical measures, such as the Glasgow Coma Scale (GCS),[5] are inconsistent predictors of neurological and functional outcome. Although neuroimaging has traditionally been used to triage patients in the emergency room, standard clinical imaging continues to underdiagnose injury. Computed tomography (CT) can detect large hemorrhages or other lesions that require surgical intervention but is insensitive to other primary and secondary injuries, some of which can be detected with conventional MRI.
The investigation and management of patients after head injury must include the accurate and complete identification of cerebral damage. Using diffusion tensor imaging, abnormalities of diffusion in patients with head injuries and unremarkable MRI have been shown for the first time.
To evaluate acute stroke with conventional, multisection diffusion-weighted (DW), and hemodynamically weighted (HW) magnetic resonance (MR) imaging.
The three MR imaging techniques were performed in 11 patients within 10 hours of the onset of acute hemiparesis. The volume of DW and HW abnormalities were compared with infarct volumes depicted at initial and/or follow-up MR or computed tomography (CT).
Findings at DW and HW imaging were abnormal in nine of the 11 patients, despite normal findings at initial CT and/or MR. In all nine patients, infarcts were depicted at follow-up CT or MR. The DW abnormality was generally smaller and the HW abnormality was generally larger than the infarct volume determined at subsequent imaging. In the two patients with normal findings at DW and HW imaging, symptoms resolved completely within 1-48 hours.
Different aspects of hyperacute cerebral ischemia are depicted at DW and HW imaging before infarction is depicted at conventional MR or CT. These techniques may improve stroke diagnosis and may contribute to advances in treatment.
This study investigated the properties of a class of rotationally invariant and symmetric (relative to the principal diffusivities) indices of the anisotropy of water self-diffusion, namely fractional anisotropy (FA), relative anisotropy (RA), and volume ratio (VR), with particular emphasis to their measurement in brain tissues. A simplified theoretical analysis predicted significant differences in the sensitivities of the anisotropy indices (AI) over the distribution of the principal diffusivities. Computer simulations were used to investigate the effects on AI image quality of three magnetic resonance (MR) diffusion tensor imaging (DTI) acquisition schemes, one being novel: the schemes were simulated on cerebral model fibres varying in shape and spatial orientation. The theoretical predictions and the results of the simulations were corroborated by experimentally determined spatial maps of the AI in a normal feline brain in vivo. We found that FA mapped diffusion anisotropy with the greatest detail and SNR whereas VR provided the strongest contrast between low- and high-anisotropy areas at the expense of increased noise contamination and decreased resolution in anisotropic regions. RA proved intermediate in quality. By sampling the space of the effective diffusion ellipsoid more densely and uniformly and requiring the same total imaging time as the published schemes, the novel DTI scheme achieved greater rotational invariance than the published schemes, with improved noise characteristics, resulting in improved image quality of the AI examined. Our findings suggest that significant improvements in diffusion anisotropy mapping are possible and provide criteria for the selection of the most appropriate AI for a particular application.
The various stages of multiple sclerosis (MS) are characterized by de- and remyelination as well as by inflammation. Diffusion MR imaging is sensitive to tissue water motion, which might correspond to these pathologic processes. Our purpose was to demonstrate differences in apparent diffusion coefficient (ADC) and diffusion tensor anisotropy in acute and chronic MS plaques and in normal-appearing brain.
Twelve MS patients underwent conventional and full-tensor diffusion MR imaging with B = 1221 s/mm2. Derivation of trace ADC and calculation of anisotropic scalars, including eccentricity, relative anisotropy (RA), and fractional anisotropy (FA) was performed on a per-pixel basis. Regions of interest of plaques and normal structures were determined on coregistered maps. MS lesions were classified as acute, subacute, or chronic on the basis of their appearance on conventional images and in relation to clinical findings.
Seven patients had acute plaques with a concentric arrangement of alternating high and low signal intensity on diffusion-weighted images. In nine acute lesions, plaque centers had high ADC with reduced anisotropy compared with rim, normal-appearing white matter (NAWM), and chronic lesions. The thin rim of diffusion-weighted hyperintensity surrounding the center showed variable ADC and anisotropic values, which were not statistically different from NAWM. Subacute and chronic MS lesions had intermediate ADC elevations/anisotropic reductions. Calculated FA pixel maps were superior to eccentricity or RA maps; however, quality was limited by signal-to-noise constraints.
ADC and diffusion anisotropic scalars reflect biophysical changes in the underlying pathology of the demyelinating process.
The major clinical use of diffusion-weighted imaging to date has been in evaluation of cerebral infarction, at which it excels. However, diffusion-weighted imaging has also shown promise for other applications, ranging from quantitative analysis of biologic changes that are not apparent from simple visual inspection of images (but are detectable after using regions of interest on apparent diffusion coefficient maps) to better characterization of other intracranial abnormalities (e.g., abscess and tumor). Both the clinical and research applications of diffusion-weighted imaging can be expected to increase, providing fresh insights into physiologic characteristics of both normal and abnormal tissue.
Magnetic resonance sequences may be designed to evaluate the diffusion movements of the protons (diffusion-weighted images, DWI). In these images, a bright signal identifies a region where the diffusion along a spatial axis is restricted. The contents of a cystic lesion frequently have the signal intensities of a generic homogeneous hyperproteinic fluid (hypointensity in T1-, hyperintensity in T2-weighted images). DWI may give further information about the microscopic organisation of these fluids: a hyperintense signal indicates the presence of a restricted diffusion, due to some kind of microscopic organisation, at the cellular or macromolecular level. This may provide additional information useful for clinical purposes. We obtained DWI in 24 consecutive patients with intracranial cystic lesions, (19 intra-axial: five abscesses, five gliomas, six metastases, two demyelinating lesions, one neurocysticercosis; five extraaxial: two arachnoid cysts, two epidermoid cysts, one cholesteatoma). We found a strongly hyperintense signal, indicating restricted diffusion, in brain abscesses, epidermoid cysts and cholesteatoma; all the remaining lesions were hypointense or mildly hyperintense. We found these data useful in critical diagnoses, such as in differentiating abscesses from tumours, and in identifying elusive tumours such as epidermoid cysts.
The goal of this study was to identify and describe the different types and patterns of tissue injury which are encountered by diffusion-weighted imaging (DWI) in diffuse axonal injury (DAI) of the brain. The DWI data sets of 98 patients who suffered from a closed-head injury were retrospectively evaluated. Medical records were reviewed to rule out pre-existing neurological diseases. Lesions were studied for their DWI signal characteristics and lesion size or extension. Traumatic lesions were classified into three categories depending on their signal characteristica on DWI and apparent diffusion coefficient (ADC) maps: type 1, DWI- and ADC-hyperintense most likely representing lesions with vasogenic edema; type 2, DWI-hyperintense, ADC-hypointense indicating cytotoxic edema; type 3, central hemorrhagic lesion surrounded by an area of increased diffusion. According to the size and extent of lesions, injury was classified into three groups: group A, focal injury; group B, regional/confluent injury; and group C, extensive/diffuse injury. Our study showed that diffusion-weighted imaging differentiates between lesions with decreased and increased diffusion in patients with DAI. Different degrees of tissue injury extent were noticed. Future prospective studies should study if this additional information can be used as a predictor of injury reversibility, final outcome and prognosis.
Diffusion tensor MR imaging in diffuse axonal injury
- K Arfanakis
- V M Houghton
- J D Carew