bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adult EEG
Authors: Britton Jeffrey W. 
Published: October 2022

Abstract
In this chapter, Artifacts and the EEG, common artifacts affecting electroencephalogram (EEG) recordings and interpretation are covered in detail. Artifacts can arise from several physiologic sources—including the eyes, heart, respiration, sweat glands, and movements of the body due to volitional activity and clinical phenomena such as tremors. They can also arise from equipment such as those due to abnormal electrode integrity or impedance, the manner in which the equipment is hooked up, filter settings, and more. Finally, factors in the patient’s environment, such as facility electricity, devices such as bed oscillators and intravenous pumps, and the act of patient care can cause artifact. Artifacts can alter the readability of the recording and mimic EEG abnormalities. Knowledge and recognition of artifacts is essential in order to provide accurate EEG interpretation.
Pediatric EEG
Authors: Nickels Katherine C. 
Published: October 2022

AbstractElectroencephalography (EEG) is an important part of the evaluation of many disorders in infants and children. However, differentiating abnormalities from normal maturational changes and benign variants can be challenging. There are also age-specific recording requirements, including acceptable duration of recording, as well as need for recording of additional physiological variables. In preterm and term infants, it is essential to determine conceptional age to determine whether the EEG patterns are appropriate for age and record at least two physiological variables in addition to the EEG. In infants and children, there is considerable variability regarding the amount of alpha, theta, and delta present, requiring an understanding of the broad ranges of normal backgrounds for each age group. Finally, as the child matures and transitions to adulthood, there are benign variants that can easily be misinterpreted as potentially epileptiform. To be able to correctly identify EEG abnormalities in children, one must be aware of the normal EEG patterns for each age group.
Computer-Assisted Ambulatory Electroencephalography
Authors: Tatum William O. 
Published: October 2022

AbstractThe usage of ambulatory electroencepholographic (EEG) monitoring has grown in popularity due to technological advances, including miniaturization and portability of smaller devices, accessibility and affordability, and similarities to inpatient video-EEG results. Ambulatory EEG is recorded in the patient’s environment and natural surroundings, which may serve as event triggers. Ambulatory EEG may be interpreted through secure wireless connections at sites distant from the hospital to enhance accessibility for interpretation. Prolonged recording increases the yield of capturing interictal epileptiform discharges or an event. Practical benefits include providing a definitive diagnosis, classification of seizure types or epilepsy syndromes, quantification of spike and seizure burdens including those experiencing seizures without self-awareness, and rarely to augment a presurgical evaluation in patients with drug-resistant focal epilepsy. Recording EEG through normal ultradian and circadian rhythms makes ambulatory EEG a logical choice compared with standard EEG; its prolonged recording may identify patient-specific patterns associated with sleep, menses, or other triggers. Ambulatory EEG may be used to evaluate response to antiseizure drug or assessing risk associated with a trial of medication withdrawal. Compared with inpatient video-EEG, ambulatory EEG is cost effective and easier to arrange with busy schedules. Currently ambulatory EEG is coupled with seizure and spike detection algorithms for assessment of prolonged time. Chronic intracranial ambulatory EEG is being evaluated coupled with responsive neuromodulation. Future attempts to provide diagnostic ambulatory EEG monitoring with therapy is emerging; efforts to move toward mobile health are ongoing. This chapter focuses on diagnostic applications of ambulatory EEG in patients suspected of epilepsy.
EEG Trend Analysis in the ICU
Authors: Crepeau Amy Z. 
Published: October 2022

Abstract
Critically ill patients in the intensive care unit (ICU) are at an increased risk for subclinical seizures or nonconvulsive status epilepticus. These seizures can be the cause of encephalopathy and potentially result in secondary neuronal injury. Though routine electroencephalograms (EEGs) can be of assistance in detection, continuous EEG monitoring has been shown to increase the yield of detecting subclinical seizures and is critical in the management of nonconvulsive status epilepticus. EEG monitoring in the ICU presents challenges not routinely encountered in the outpatient EEG laboratory or the epilepsy monitoring unit. These challenges include multiple sources of artifact, need for imaging-compatible electrodes, and a robust information technology support system. Once EEG monitoring is established, rhythmic and periodic patterns of indeterminate significance are encountered, challenging the electroencephalographer and the care team. There is much debate regarding the clinical significance of these patterns; ultimately, clinical correlation is always required. Special techniques can be employed in the application and analysis of ICU EEG monitoring. EEG allows for a window into cerebral activity, and it has been of assistance in monitoring for ischemia, prognosis, and depth of medication-induced suppression. Quantitative EEG can also be utilized to assist in rapid seizure detection and to monitor for subtle changes in cerebral function that occur over hours. EEG monitoring is an important tool in the ICU for the purposes of seizure detection and cerebral monitoring. The special environment, however, requires close attention to technical considerations and thoughtful interpretations of indeterminate patterns.
Intracranial EEG Monitoring and Electrocorticography
Authors: Feyissa Anteneh M. 
Published: October 2022

Abstract
In patients with drug-resistant focal epilepsy, precise localization of the “epileptogenic zone” (EZ) is crucial for optimal surgical outcomes. For “skip candidates,” this can be achieved by performing scalp video-EEG (electroencephalographic) monitoring and brain imaging studies. Unfortunately, 25%–50% of cases also require intracranial EEG (iEEG) recording, using primarily subdural grid (SDE) or stereotactic EEG (SEEG) electrodes. The decision about which method to use is mainly dependent on the specific question and suspected location of the EZ. While the precise localization of the EZ within the neocortex is best achieved using SDE, SEEG is preferred when the EZ is in the deep neocortex. Although the two methods differ in their indication, they complement each other and, in some cases, could be employed simultaneously. This chapter discusses the indications, techniques, interpretation, and complications of iEEG. Direct cortical stimulation for functional mapping and tailoring margins of resection is also briefly discussed.
Motor Nerve Conduction Studies
Authors: Jones Lyell K. , Watson James C. , Rubin Devon I. 
Published: October 2022

Abstract
Electrodiagnostic testing is an important part of the evaluation of patients with focal or diffuse neuromuscular disorders. Assessment of compound muscle action potentials (CMAPs) is an essential nerve conduction study (NCS) technique that permits quantitative measurement of peripheral motor function. Since disease of the axons, neuromuscular junctions, or muscle fibers can alter the CMAP, motor NCS can be used to assess disease at each of these locations. This chapter outlines the general physiological and technical principles that practitioners should understand to obtain high-quality CMAPs. It describes how to interpret CMAP changes in the appropriate clinical setting and in the context of a comprehensive electrodiagnostic evaluation. CMAPs are useful diagnostic tools in many neuromuscular disorders, and several common clinical scenarios are presented here.
Cranial Reflexes and Related Techniques
Authors: Smith Benn E. 
Published: October 2022

Abstract
The trigeminal and facial nerves and their central connections may be involved in a number of neurological disorders. Electrophysiological study of the reflex activity mediated by the fifth and seventh cranial nerves have been useful in particular for assessing cranial neuropathies (e.g., Bell palsy) or peripheral facial movement disorders, such as hemifacial spasm or facial synkinesis. In addition, these techniques can provide useful information in some cases of peripheral neuropathy, polyradiculoneuropathy, brainstem lesions, motor neuron disease, progressive supranuclear palsy, and corticobasal syndrome. The reflexes discussed in this chapter are the electrically evoked blink reflex, the jaw jerk (or masseter reflex), the masseter inhibitory reflex, and less commonly used electrophysiologic techniques for studying cranial nerves IX and X. Also, two additional techniques are also discussed: one to assess a sensory nerve in the head that is not a cranial nerve of branchial arch origin, the great auricular sensory nerve, and the other to interrogate trigeminal sensory pathways from the sensory receptor level to the parietal cortex, contact heat-evoked potentials.
Quantitative Motor Unit Number Estimates
Authors: Sorenson Eric J. , Daube Jasper R. 
Published: October 2022

Abstract
Quantitative motor unit number estimates (MUNE) are neurophysiological techniques designed to quantitate the number of viable motor axons that innervate a muscle or muscle group. A variety of techniques have been developed to accomplish this, each with its own advantages and disadvantages. Traditionally, the MUNE is calculated from the supramaximal compound muscle action potential (CMAP) by dividing the CMAP by the mean size of the motor unit potentials. The resulting unitless number represents the number of motor units within a muscle or muscle group. These techniques vary by how this mean motor unit potential size is calculated. These methods have been applied most widely to disorders of the motor neuron, such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy, and polio. MUNE has been used as a research measure in animal and human studies. Additionally, it has been used as an outcome measure in clinical trials for ALS and spinal muscular atrophy. More recently, two techniques have been developed that rely on statistical calculations from the CMAP and are fundamentally unique from the traditional methods. These have been called the MUNIX and MScanFit methods. These newer methods are faster to apply and can be performed with less patient discomfort. This chapter reviews the traditional and newer technique of motor unit number estimation.
Technical Issues and Potential Complications of Nerve Conduction Studies
Authors: Rubin Devon I. 
Published: October 2022

Abstract
Nerve conduction studies (NCSs) are an important component of a routine electrodiagnostic study and provide valuable information about the function of peripheral nerves, neuromuscular junctions, and muscle. While NCS techniques are standardized and often straightforward in experienced hands, they are fraught with a variety of potential technical problems that may interfere with reliable acquisition of data. Recognition, identification, and correction of technical problems are critical to the accurate interpretation of any electrodiagnostic study. NCSs are safe to perform, but they involve the administration of electric current to the patient and may pose some potential risks in certain clinical circumstances. This chapter reviews technical problems that may occur during the performance of NCSs as well as the potential risks of NCSs.
Single-Fiber Electromyography
Authors: Crum Brian A. , Harper C. Michael 
Published: October 2022

Abstract
Single-fiber EMG (SFEMG) is a specialized electrophysiological technique used to assess for neuromuscular junction diseases. The selectivity of SFEMG depends on the use of a low-frequency filter of 500 Hz and a small electrode size. Voluntary activation or electrical stimulation is used to activate the muscle fibers in SFEMG. SFEMG assesses the relationship in the generation of the action potentials between two time-locked muscle fibers. The primary measurements that are used to determine the adequacy of neuromuscular transmission are jitter and blocking. Unique aspects of SFEMG relate to equipment, software, and technique, which must be understood fully in order to perform high-quality studies. Abnormalities on SFEMG testing need to be taken into consideration with the clinical history, examination, and other electrophysiological tests.
Electrodiagnostic Assessment of Motor Neuron Diseases
Authors: Staff Nathan P. 
Published: October 2022

Abstract
The importance of electrodiagnostic testing in a patient with painless progressive weakness cannot be understated as it may distinguish between neuromuscular diseases with widely disparate prognoses and treatment options. It is particularly useful to determine the neuroanatomical extent of motor neuron dysfunction and its acuity. This can help the clinician refine their differential diagnosis and provide prognostic information for the patient. Diseases of the motor neuron with this clinical presentation may include amyotrophic lateral sclerosis, multifocal motor neuropathy, or spinobulbar muscular atrophy. In this chapter, the electrodiagnostic approach to this clinical problem is discussed. Subsequently, specific diseases of the motor neuron and their electrodiagnostic testing are described.
Assessment of Neuromuscular Junction Diseases
Authors: Naddaf Elie 
Published: October 2022

Abstract
Neuromuscular junction diseases are characterized by fluctuating muscle weakness in various distributions. Patients with similar symptoms are commonly referred for electrodiagnostic testing to confirm or exclude a neuromuscular transmission defect. This chapter details the role of electrodiagnostic testing in the approach to such patients. Routine nerve conduction studies and needle electromyography help to evaluate for alternative causes. Repetitive nerve stimulation and single fiber EMG remain the cornerstone of the electrodiagnostic workup of neuromuscular junction disorders. The chapter describes the utility of these advanced techniques, underscoring their technical intricacies. Finally, it provides a practical electrodiagnostic approach to specific neuromuscular junction diseases.
Neuromuscular Electrodiagnostic Testing in the Intensive Care Unit
Authors: Goodman Brent P. 
Published: October 2022

Abstract
The electrodiagnostic (EDX) evaluation of suspected neuromuscular conditions in the intensive care unit (ICU) requires a thoughtful approach, with particular attention to technical factors that can impact testing in this setting and knowledge of how the various neuromuscular conditions translate into EDX findings for these patients. Electrodiagnostic testing is typically performed in the ICU in order to identify a neuromuscular cause for respiratory failure and weakness. An approach to EDX testing and typical findings in ICU- acquired weakness and primary neuromuscular conditions such as Guillain-Barré syndrome, myasthenic crisis, West Nile poliomyelitis, amyotrophic lateral sclerosis, and other neuromuscular conditions encountered in ICU patients are discussed.
Neuromuscular Ultrasound in the EMG Laboratory
Authors: Boon Andrea J. 
Published: October 2022

Abstract
Neuromuscular ultrasound is a rapidly evolving imaging field that is an ideal diagnostic adjunct to clinical neurophysiology. Where electromyography (EMG) and nerve conduction studies (NCSs) can demonstrate the pathophysiology of a lesion, ultrasound can often determine the underlying cause. Ultrasound is noninvasive, safe, portable, and relatively inexpensive compared to magnetic resonance imaging. High-definition imaging of nerves and muscles allows the electrodiagnostician to identify causes of entrapment, such as cysts, fascial bands, tumors, sites of multifocal or uniform nerve enlargement in more generalized polyneuropathies, and changes in muscle echotexture associated with fibrous or fatty replacement of muscle fibers seen in dystrophies, inflammatory myopathies, and denervation. Ultrasound guidance can enhance the accuracy and safety of NCSs and needle EMG in certain situations, such as obesity, altered anatomy, anticoagulation, or when testing in close proximity to vital structures such as the lung or large blood vessels.
Visual Evoked Potentials
Authors: Carter Jonathan L. 
Published: October 2022

Abstract
Visual evoked potentials (VEPs) are used to evaluate the functional integrity of the anterior visual pathways. Reliable recording of VEPs requires an alert patient with a visual acuity of 20/200 or better who is able to fixate on the target screen. The P100 waveform is easily recorded over the occipital cortex in normal individuals. Abnormalities may include reduced amplitude or absent P100 waveforms and/or slowing of latencies between the retina and cortex. Abnormalities are not specific for pathology in the visual pathways, but demyelinating lesions of the optic nerve or chiasm typically produce prolonged latencies with normal or slightly reduced amplitudes. Latency is considered more reliable than amplitude. Unilateral prolongation of P100 latency, either absolute or relative to the companion eye, suggests unilateral anterior visual pathway involvement. Bilateral P100 latency prolongation is nonlocalizing as it could reflect either bilateral anterior visual pathway involvement or a retrochiasmatic lesion. Clinical utility of VEPS is greatest for detecting abnormalities in patients with suspected inflammatory optic neuritis and for determining asymptomatic lesions in multiple sclerosis and other demyelinating diseases to establish dissemination of lesions in space. VEPs may have higher sensitivity for detecting optic nerve lesions than magnetic resonance of the orbits. Technical factors are important to obtain reliable, reproducible results. False-positive results can occur due to poor patient cooperation. The results should be interpreted within the clinical context presented by the patient and should not by themselves be used to establish a diagnosis of multiple sclerosis or other demyelinating disease.
Motor Evoked Potentials
Authors: Mauricio Elizabeth A. 
Published: October 2022

Abstract
Motor evoked potentials can be generated by either electrical or magnetic stimulation of the corticospinal pathways. Direct activation of pyramidal cells and indirect activation of cortical interneurons generate impulses that propagate down the spinal cord as D-waves and I-waves, ultimately stimulating anterior horn cells and resulting in M-waves recorded over the targeted muscle. Transcranial electrical stimulation is most commonly employed in the operating room for intraoperative neurophysiologic monitoring, ensuring that the integrity of the motor pathways are preserved during brain or spine surgeries. The utility of transcranial magnetic stimulation has been explored in many neurologic diseases, where alterations in central motor conduction time and cortical excitability may provide important clues in diagnosis, prognosis, and monitoring response to treatment.
Evaluation of Adrenergic Function
Authors: Low Phillip A. , Singer Wolfgang 
Published: October 2022

Abstract
The purpose and role of adrenergic function testing in the clinical setting is to assess for autonomic disorders that involve maintenance and regulation of blood pressure and heart rate; it furthermore adds to the assessment of other domains of autonomic function in order to define the distribution of autonomic deficits. Simple, accurate, and reproducible tests of adrenergic function are now routinely used in clinical autonomic laboratories. This chapter focuses on the most widely used tests to evaluate adrenergic function in an autonomic laboratory, namely, beat-to-beat blood pressure and heart rate responses to the Valsalva maneuver and head-up tilt. It is possible to separately evaluate the vagal and adrenergic components of baroreflex sensitivity.
Cardiovagal Reflexes
Authors: Coon Elizabeth A. , Cheshire William P. 
Published: October 2022

Abstract
Assessment of cardiovagal function can be reliably and reproducibly performed using noninvasive tests of cardiovascular function. Measurement of heart rate responses to deep breathing assesses the integrity of afferent and efferent vagal pathways. Measuring heart rate response to Valsalva assesses the vagal component of the baroreflex and should be done with simultaneous recording of arterial pressure. Using heart rate recordings from the Valsalva maneuver, the Valsalva ratio can be computed from the maximal heart rate response to phase II and the minimal heart rate response during phase IV, while baroreflex sensitivity can be measured by plotting each heart interval against the preceding systolic blood pressure value, leading to the slope of the simple linear regression. Quantitative grading of cardiovagal function can be performed using the composite autonomic severity scale. The following chapter describes the physiology, methodology, clinical utility, and shortcomings of the most clinically used tests of cardiovagal function.
Electrophysiology Testing of Movement Disorders
Authors: Klassen Bryan T. , Caviness John N. , Bower James H. 
Published: October 2022

AbstractThe gold standard for diagnosis of most movement disorders remains a careful neurologic examination; however, neurophysiologic evaluation can often complement the clinical examination. Rather than focus on specific electromyographic (EMG) spike morphologies, as is done in neuromuscular EMG, movement disorder neurophysiology studies focus on the pattern of discharges over time and in relation to patterns in other muscles. Thus, surface EMG polygraphy is the main method used, at times in conjunction with simultaneous EEG. Tremor, dystonia, and myoclonus can all be evaluated in this manner. Evoked responses are also useful, particularly to evaluate some types of myoclonus and startle disorders. In order to fully integrate movement neurophysiology into the comprehensive care of patients with movement disorders, a good understanding of both the neurophysiologic techniques and the underlying disease states is necessary; this chapter provides an overview of both.
Assessment of Sleep and Sleep Disorders: Polysomnography and Other Tests
Authors: Silber Michael H. , Harris Cameron D. 
Published: October 2022

Abstract
Soon after the human electroencephalogram was discovered in 1929, researchers began recording brain electrical activity during sleep. In 1937, Loomis described and classified non–rapid eye movement sleep, and in 1953, rapid eye movement sleep was discovered by Aserinsky and Kleitman. In the 1960s, seminal discoveries were made delineating the disturbances in sleep physiology in narcolepsy and obstructive sleep apnea. The clinical evaluation of sleep and its disorders began in the early 1970s, eventually leading to the development of the medical specialty of sleep medicine. The number of clinical sleep laboratories, most within comprehensive sleep centers, has steadily grown. New methodologies have been developed, including the use of various techniques for monitoring sleep and its disturbances in the home environment. The goal of this chapter is to review the techniques used to study sleep and to discuss the physiological parameters recorded.