Why is electrophysiology used to treat neurological diseases?
Many neurological diseases cause symptoms that manifest far from the injured or deceased tissues. Locating and treating all affected areas of the body is essential for proper patient care. Electrophysiology allows for the investigation of abnormal electrical signals in the body’s tissues.
Can brain electrophysiology be modified through learning?
Until about 40 years ago, it was generally believed that brain electrophysiology was not under conscious control and could not be modified through learning.
What are electrophysiological techniques for clinical diagnosis?
Electrophysiological techniques for clinical diagnosis will discuss the techniques borrowed from electrophysiology used in the clinical diagnosis of subjects. There are many processes that occur in the body which produce electrical signals that can be detected.
Can electrophysiology measure the effects of alcohol on the brain?
Electrophysiology has provided several excellent measures of acute and chronic effects of alcohol on the brain.
What is electrophysiology in clinical diagnosis?
ascertain electrical signals from the human body for diagnosis. Electrophysiological techniques for clinical diagnosis will discuss the techniques borrowed from electrophysiology used in the clinical diagnosis of subjects. There are many processes that occur in the body which produce electrical signals that can be detected.
Why is electrophysiology important?
Electrophysiology has a very important role in ensuring accurate clinical diagnoses. Many neurological diseases cause symptoms that manifest far from the injured or deceased tissues. Locating and treating all affected areas of the body is essential for proper patient care. Electrophysiology allows for the investigation of abnormal electrical ...
What is EMG used for?
EMG is used to determine the onset of muscle activity in spastic muscles, allowing for comparison between affected patients and asymptomatic individuals. Measurement tools involving EMG are argued to be more sensitive than currently used clinical scales like the Modified Ashworth Scale (MAS) in detecting spasticity symptom severity. The use of EMG offers a quantitative value of severity as opposed to relying on subjective scoring protocols. Malhotra et al. (2008) used EMG and the MAS to determine which method was more effective in detecting spasticity of the wrist flexors. In their sample of 100 patients (median age 74 years), they found that using EMG to detect onset of muscle activity during multiple passive stretch repetitions of the wrist at various velocities, successfully detected spasticity in 87 patients while the MAS only detected spasticity in 44 of these individuals. These findings support the use of EMG as a more sensitive diagnostic tool than the MAS and therefore advantageous when used in a clinical setting. Similarly, EMG was successful in detecting elbow flexor spasticity symptom improvement in six post-stroke subjects (mean age 54.16 ± 7.9 years) following a neural mobilization technique of the median nerve. At 90 degrees of flexion and full extension of the elbow, muscle activity decreased from 17% pre-treatment to 11% post-treatment. These patients had initial MAS scores of 1 or 2, and the MAS was incapable of detecting the same symptom improvements post-treatment as seen with the EMG method.
What is EMG in medical terms?
Electromyography (EMG) Main article: Electromyography. Electromyography is the measurement and analysis of the electrical activity in skeletal muscles. This technique is useful for diagnosing the health of the muscle tissue and the nerves that control them.
What is the purpose of electroencephalography?
Electroencephalography is the measurement of brain activity through the surface of the scalp. Electroencephalography data can be processed through analytical procedures and certain derived summary indices of these analyses are called quantitative electroencephalography (QEEG). Data from evoked potentials can also be used processed in certain ways that can be considered quantitative EEG as well. If QEEG data is mapped then it is a topographic QEEG (also known as brain electrical activity mapping or BEAM )
What is dementia EEG?
Alzheimer’s disease and other types of dementia diagnosis is being improved through the use of electroencephalogram (EEG) and event-related potentials (ERP).
What are the sources of electromagnetic waves?
There are various techniques available to study and measure the electromagnetic signals of the body. The brain, the heart and skeletal muscles are prime sources of electric and magnetic fields that can be recorded and the resulting patterns can give insight on what ailments the subject may have.
What is electrophysiology in neuroscience?
Electrophysiology is the branch of neuroscience that explores the electrical activity of living neurons and investigates the molecular and cellular processes that govern their signaling. Neurons communicate using electrical and chemical signals. Electrophysiology techniques listen in on these signals by measuring electrical activity, allowing scientists to decode intercellular and intracellular messages. The purpose of this chapter is to differentiate between the major categories of electrophysiological techniques and preparations, comparing the relative advantages, disadvantages, and common uses of each. To explain how these techniques are performed, the chapter describes the instruments that make up an electrophysiology setup (“the rig”). It also examines some common methods of data analysis and presentation used in the literature. Finally, it describes methods of manipulating neural activity during electrophysiology experiments. However, before describing electrophysiological techniques, it is necessary to have an understanding of what electrophysiology experiments attempt to measure. Therefore, the chapter starts with a brief review of the physical principles that provide neurons their electrical characteristics.
What equipment is needed for electrophysiology?
In general, a signal is detected by a microelectrode, which transmits that signal to an amplifier, an oscilloscope, and a computer. The oscilloscope presents a visual display of the membrane potential over time, which can also be heard using a loudspeaker system. In modern electrophysiology rigs, the oscilloscope is now completely digital and part of a software program on the computer. An electrophysiology setup also includes equipment to stabilize the microelectrode and correctly position it to record from a neuron of interest. A microscope is used to ensure proper placement of the electrode for in vitro recordings, while stereotaxic equipment ( Chapter 3) is used to position electrodes for in vivo recordings. Box 4.1 details various components of a standard electrophysiology rig.
Why are glass micropipettes used in electrophysiology?
Glass micropipettes are necessary for patch clamp recordings because of the way the pipette must make a tight seal with the cell membrane (as discussed later in the chapter). For intracellular or extracellular electrophysiology experiments, metal electrodes are more commonly used. These metal electrodes not only provide more stable isolation of single units than micropipettes, but they tend to sample from a larger morphological variety of cells and also help in better localization of electrode tracks to identify where recordings took place in whole brains. The main advantage of using a glass electrode in extracellular or intracellular experiments is that the pipette can be filled with a dye or other materials that can subsequently be injected into the cell or cellular environment for staining and/or pharmacological experiments.
How to see changes in voltage?
Changes in voltage over time are visualized using an oscilloscope or digital oscilloscope, but they can also be heard by connecting the output of the amplifier to a loudspeaker. Action potentials make a distinctive popping sound, so recording the activity of an active neuron can sound like popcorn popping. Loudspeakers can be helpful when trying to locate a neuron of interest, because different types of neurons have distinctive firing patterns. An investigator lowering an electrode into neural tissue using a microdrive can be alerted to a specific type of cell or group of nuclei by the characteristic sounds of neurons near the electrode tip.
Why use glass electrodes in cellular experiments?
The main advantage of using a glass electrode in extracellular or intracellular experiments is that the pipette can be filled with a dye or other materials that can subsequently be injected into the cell or cellular environment for staining and/or pharmacological experiments.
How is an electrical signal recorded?
In general, an electrical signal is recorded by a microelectrode and passed along to an amplifier. The amplifier compares the recording to a ground electrode, then transmits the signal to an oscilloscope and/or computer. Various other equipment is necessary and desirable depending on the nature of the experiment.
What are the two types of electrodes?
There are two main types of electrodes: (1) glass micropipettes filled with an electrolyte solution (2 or 3 M sodium chloride or potassium chloride); and (2) metal electrodes (usually tungsten, steel, or platinum–iridium).
Abstract
Electroencephalography (EEG) is a powerful and inexpensive bedside tool for the assessment of residual brain function in prolonged disorders of consciousness. Here we review a range of methods for EEG interpretation, including reactivity, perturbation by transcranial magnetic stimulation, evoked potentials, and oscillatory changes.
About this chapter
Cruse D., Young G.B., Piccione F., Cavinato M., Ragazzoni A. (2016) Brain Electrophysiology in Disorders of Consciousness: Diagnostic and Prognostic Utility. In: Monti M., Sannita W. (eds) Brain Function and Responsiveness in Disorders of Consciousness. Springer, Cham. https://doi.org/10.1007/978-3-319-21425-2_9
What is the field of study that uses electrical technology to study human neurophysiology?
Electrodiagnosis is the field of study that, by employing the science of electrophysiology, uses electrical technology to study human neurophysiology. Neurodiagnostics (NDS), electromyography (EMG), and evoked potentials (EPs) are aspects of electrodiagnosis .
What is electrodiagnosis in medical terms?
Electrodiagnosis is the field of study that, by employing the science of electrophysi ology, uses electrical technology to study human neurophysiology. Neurodiagnostics (NDS), electromyography (EMG), and evoked potentials (EPs) are aspects of electrodiagnosis. Information needed to answer any questions regarding nerve injury, muscle injury, ...
What is the American Board of Electrodiagnostics?
The American Board of Electrodiagnostics was developed to provide additional certification for physicians who perform electrodiagnostic tests, and this certification is considered the criterion standard for specialty training. The American Board of Neurology also has a subspecialty certification for neurologists with specialty training in electrodiagnosis. [ 4]
What is the first electrodiagnostic test?
Electromyography. EMG was the first electrodiagnostic test to be developed. This procedure involves the placement of a needle into various muscles to record different stages of muscle activity, including rest, minimal contraction, and maximal activity. At rest, normal muscle is electrically silent.
Why do we need serial EMG?
In a traumatic nerve injury or acute neuropathic process, serial EMG is often performed to assess disease progression or response to treatment, as well as to aid in prognosis.
How does neurodiagnostic testing work?
This electrical signal causes the muscle to contract. Neurodiagnostic testing bypasses the brain by delivering an electrical charge to the patient. The equipment then is used to measure several aspects of the body's response to that signal to determine whether it is functioning properly.
What is the current trend in electromyography?
A current worrisome trend is the performance of electromyographic testing by nonphysician health care personnel. The performance of electromyography and the interpretation of electromyograms require technical skill and the ability to integrate the physician's knowledge base of disease pathology with diagnostic acumen.
How does STN-DBS help with PD?
STN-DBS can improve the motor symptoms of PD patients and improve the quality of life . The closer the stimulation is to the STN dorsolateral sensorimotor area, the higher the DBS is to improve the motor symptoms of PD patients.
Why are the datasets used and/or analyzed during the current study not publicly available?
The datasets used and/or analyzed during the current study not publicly available due to privacy reasons of patients, but are available from the corresponding author on reasonable request.
Where is the Hebei Medical University?
2Department of neurosurgery, the First Hospital of Hebei Medical University, Shijiazhuang, 050031 Hebei China
Is deep brain stimulation a neurodegenerative disease?
PD is a neurodegenerative disease common in middle-aged and elderly people, and deep brain stimulation (DBS) is an accepted treatment at an advanced stage [1, 2]. Studies have shown that subthalamic nucleus (STN) DBS can improve dyskinesias and improve the quality of life (QOL) in PD patients [3–6].