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Stereoelectroencephalography
Stereoelectroencephalography (SEEG) is the practice of recording electroencephalographic signals via depth electrodes (electrodes surgically implanted into the brain tissue). It may be used in patients with epilepsy not responding to medical treatment, and who are potential candidates to receive brain surgery in order to control seizures. This technique was introduced in the diagnostic work up of patients with epilepsy by the group of the S. Anne Hospital, Paris, France, in the second half of the 20th century. Intracerebral electrodes are placed within the desired brain areas to record the electrical activity during epileptic seizures, thus contributing to define with accuracy the boundaries of the "epileptogenic zone", i.e. the area of brain generating the seizures which should be eventually surgically resected to achieve freedom from epileptic seizures. Potential risks of the procedure, accounting for less than 1% of cases, include brain hemorrhage and infection, which can lead t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electroencephalography
Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex and allocortex. It is typically non-invasive, with the EEG electrodes placed along the scalp (commonly called "scalp EEG") using the International 10-20 system, or variations of it. Electrocorticography, involving surgical placement of electrodes, is sometimes called " intracranial EEG". Clinical interpretation of EEG recordings is most often performed by visual inspection of the tracing or quantitative EEG analysis. Voltage fluctuations measured by the EEG bioamplifier and electrodes allow the evaluation of normal brain activity. As the electrical activity monitored by EEG originates in neurons in the underlying brain tissue, the recordings made by the electrodes on the surface of the scalp vary in accordance with their orientation and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain
A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains approximately 14–16 billion neurons, and the estimated number of neurons in the cerebellum is 55–70 billion. Each neuron is connected by synapses to several thousand other neurons. These neurons typically communicate with one another by means of long fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells. Physiologically, brains exert centralized control over a body's other organs. They act on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated respon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epilepsy
Epilepsy is a group of non-communicable neurological disorders characterized by recurrent epileptic seizures. Epileptic seizures can vary from brief and nearly undetectable periods to long periods of vigorous shaking due to abnormal electrical activity in the brain. These episodes can result in physical injuries, either directly such as broken bones or through causing accidents. In epilepsy, seizures tend to recur and may have no immediate underlying cause. Isolated seizures that are provoked by a specific cause such as poisoning are not deemed to represent epilepsy. People with epilepsy may be treated differently in various areas of the world and experience varying degrees of social stigma due to the alarming nature of their symptoms. The underlying mechanism of epileptic seizures is excessive and abnormal neuronal activity in the cortex of the brain which can be observed in the electroencephalogram (EEG) of an individual. The reason this occurs in most cases of epilepsy is u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrocorticography
Electrocorticography (ECoG), or intracranial electroencephalography (iEEG), is a type of electrophysiological monitoring that uses electrodes placed directly on the exposed surface of the brain to record electrical activity from the cerebral cortex. In contrast, conventional electroencephalography (EEG) electrodes monitor this activity from outside the skull. ECoG may be performed either in the operating room during surgery (intraoperative ECoG) or outside of surgery (extraoperative ECoG). Because a craniotomy (a surgical incision into the skull) is required to implant the electrode grid, ECoG is an invasive procedure. History ECoG was pioneered in the early 1950s by Wilder Penfield and Herbert Jasper, neurosurgeons at the Montreal Neurological Institute. The two developed ECoG as part of their groundbreakinMontreal procedure a surgical protocol used to treat patients with severe epilepsy. The cortical potentials recorded by ECoG were used to identify epileptogenic zones †... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
