EEG
EEG Electroencephalography is diagnostic method that allowing measurement and recording of brain electrical activity. It is the process of recording the electrical activity of the brain and it is done by printing to certain standards, digital media or paper by following the internationally accepted mapping process. The brain is constantly in electrical activity and at certain periods of life, this electromagnetic activity shows marked improvement levels, and at certain stages of daily life such as sleep and alertness it continues its electrical activity at certain standards.It is basic method used in neurology and psychiatry. Electroencephalograph is device for measurement of electrical potentials of brain.There are two kind of EEG; Classic EEG and Evoked potentials(EP). While measurement is performed without external stimulation in Classic EEG, the brain electrical activity is measured during external sensory stimulation in Evoked potentials.There are 3 kinds Evoked potentials; Visual Evoked Potential,Auditory Evoked Potentials,Somatosensoric Evoked Potentials.For recording of EP, there is used a special software where less channels are recorded but the sampling frequency is higher. In order to evaluate electroencephalography, it is necessary to follow certain rules in recording. Recording is achieved by standardizing the signals obtained from electrodes placed on the scalp and the earlobe in standardized studies. EEG measurement is a cap made of elastic fabric, which contains electrodes placed according to 10-20 system which use of electroconductive gel.The other measurement is single electrode that use of electrode paste.There many types brain activity that we can measure by EEG; Beta,Alpha,Theta,Delta etc. The minimum requirements for EEG registration are as follows: >Monopolar electrode earlobe, other electrode on the scalp >Bipolar recording with sufficient time with links on both electrode scalp, >Eye opening application, and >Provocation applications. >Routine applications in provocation applications, Intermittant fotic stimulation applications and hyperventilation applications at different frequencies. Sleep also has special effects on the electrical activity of the brain, different stages of the spontaneous and provoked sleep EEG, as well as other units provided ,like eye movements, ECG, EMG, concurrent recording of the respiratory record all the sleep stages by recording sleep diseases, parasomnias asleep epilepsy (polysomnography). The patient’s age, sex, pre-diagnosis, clinical information, medications and doses used, the condition of the patient during the shooting period (anxiety condition, drowsiness, coma, diazem, etc., whether the cooperative status, relationship with the environment) should be specified. In addition, eye opening, closure,and hyperventilation during shooting with the patient remarkable situations (swallowing, sleep, seizure, etc.) should be simultaneously indicated on the trase that the evaluation should be done in the most accurate way.It is called Multichannel EEG record.
