Auditory Evoked Magnetic Fields And Electric Potentials

This book reviews how we can record the human brain's response to sounds, and how we can use these recordings to assess hearing. These recordings are used in many different clinical situations--the identification of hearing impairment in newborn infants, the detection of tumors on the auditory nerve, the diagnosis of multiple sclerosis. As well they are used to investigate how the brain is able to hear--how we can attend to particular conversations at a cocktail party and ignore others, how we learn to understand the language we are exposed to, why we have difficulty hearing when we grow old. This book is written by a single author with wide experience in all aspects of these recordings. The content is complete in terms of the essentials. The style is clear; equations are absent and figures are multiple. The intent of the book is to make learning enjoyable and meaningful. Allusions are made to fields beyond the ear, and the clinical importance of the phenomena is always considered.

The past decade has seen a rapid increase in the application of electrophysiologic measurement techniques in evaluating patients with hearing and balance disorders. Advances in computer technology have generated new and exciting applications in the areas of electrocochleography, electroneuronography, electronystagmography, and the auditory brainstem response. This book examines these recent developments and explores new areas of the field currently under investigation. An important issue in electrocochleography today is the widened AP-SP complex. Contributors to this book evaluate its significance in patients with cerebellopontine angle tumor. The many applications of the auditory brainstem response are surveyed, as well as the current status of the mid- and long-latency evoked responses. An overview of the relatively new area of otoacoustic emissions and its clinical applications is also included. Practicing otolaryngologists, otolaryngology residents, audiologists, audiology students, and auditory and vestibular scientists will benefit most from this well-researched book.

Written by experts with extensive clinical and scientific experience, this comprehensive textbook presents the state of the art in auditory evoked potentials. Opening chapters explain the nature of electrical fields that generate surface recorded potentials, summarize the imaging modalities that complement evoked potential studies, and review acoustics and instrumentation. Major sections examine the anatomy and physiology of the auditory periphery, brainstem, and cortex and the principles and clinical applications of auditory, myogenic, visual, somatosensory, and vestibular evoked potentials. Chapters present hands-on laboratory exercises and clinical case studies. A full-color insert includes 3D images from multi-channel evoked potentials and functional imaging.

Recent concerns over the possible hazards of electrical and magnetic fields in the home and workplace are comprehensively addressed within this book. The chapters contain detailed research on the biological effects of electric and magnetic fields, and evidence for and against any interaction of electromagnetic fields (EMFs) and the biological systems. The relative risk of exposure to EMFs Putative behavioral and neural effects of EMFs EMF effects on cells

The clinical electrophysiology of the human somatosensory cortex was investigated with a combined approach using cortical stimulations and somatosensory evoked responses on electrocorticography, scalp-EEG, and magnetoencephalography, a new neurophysiological technique. The spatiotemporal structure of the evoked response was studied with novel biophysical modeling techniques which allowed identification of the three-dimensional intracerebral location, time activity, and interaction of the neuronal sources in human somatosensory cortex. Thus, new aspects on the functional anatomy of the human somatosensory cortex could be elicited. Furthermore, the somatotopy of the hand somatosensory cortex was investigated. Clinically, the results of comparison of the different techniques can improve the non-invasive localization criteria for primary motor and somatosensory cortex which is important in patients undergoing neurosurgical procedures adjacent to central fissure.

Auditory Brainstem Evoked Potentials: Clinical and Research Applications provides a solid foundation of the theoretical principles of auditory evoked potentials. This understanding is important for both the development of optimal clinical test strategies, and interpretation of test results. Developed for graduate-level audiology students, this comprehensive text aims to build a fundamental understanding of auditory evoked brainstem responses (ABR), and their relationship to normal and impaired auditory function, as well as its various audiologic and neurootologic applications. In addition to covering the classical onset ABR, the book provides a thorough review of sustained brainstem responses elicited by complex sounds, including auditory steady state response (ASSR), envelope following response (EFR), and frequency following response (FFR), and the growing clinical and research applications of these responses. By exploring why certain stimulus manipulations are required to answer specific clinical questions, the author provides the resources needed for students and clinicians to make reasoned decisions about the optimal protocol to use in a given situation. Key Features: * A full chapter devoted to laboratory exercises * Numerous illustrations to help explain key concepts * Description of neural bases underlying amplitude and latency changes * Troubleshooting techniques * End-of-chapter summaries