It is the process of recording the electrical activity of the brain and is performed in accordance with the internationally accepted mapping process with certain standards, digital media or printing on paper. The brain is in constant electrical activity and shows significant levels of development in certain circuits of life, and continues its electrical activity in certain phases of daily life (such as sleep and wakefulness) to certain standards.
In order to be able to evaluate electroencephalography, certain rules must be followed in recording. The recording process is achieved by amplifying signals from electrodes placed on the scalp and on the earlobes in standard studies.
Minimum applications required during registration, in order:
Monopolar one electrode earlobe, other electrode on scalp
Bipolar recording time enough with connections on both electrodes scalp,
Eye-opening practice, and
They are practices of provocation.
Provocation practices, routine practices,
It is the applications of intermittant photic stimulation and hyperventilation at different frequencies. Is also needed
Sound and not so implemented now,
Insulin provocation practices can also be counted among the provocation methods.
In addition to recording spontaneous and provoked sleep EEG, other team names are provided (eye movements, EKG, EMG, respiratory records are performed simultaneously) and all sleep phases are recorded so that sleep diseases, parasomnies sleep epilepsy can be examined (polysomnography)
Long-term EEG monitoring and telemetric EEG monitoring for daily recording in case of absence of pathological findings in interictal circuits, simultaneous recording with Video can also find application areas for recording clinical seizures along with changes in EEG.
What should be considered when withdrawing EEG?
The patient’s age, sex, pre-diagnosis, clinical information, the drugs and doses used, the status of the patient (anksiete status, sleepy, comatose, diazem, etc.) during the duration of the shooting should be indicated. In addition, eye opening, closing, photic stimulation and hyperventilation during shooting, the patient’s attention points (swallowing, licking, seizure, etc.) should be stated simultaneously on the trase so that the evaluation is performed in the most accurate way.
After that, the evaluation can be passed and the following evaluation is done in order.
Is the ground activity consistent with the patient’s age, current condition, medication, illness? Is there any significant difference between the previous records ? these must be specified. (which shows certain characteristics in certain age groups, drug use and sleep, some metabolic, inflammatory, degenerative diseases may be abnormal in the organization of the ground activity.)
The effect of eye opening application on ground activity, (often eye opening, causes voltage suppression in ground activity.)
The presence of asymmetry between both brain hemispheres (subdural hematoma, cerebral infarction, mass, sometimes voltage suppression and may cause deceleration, unilateral encephalitis can cause asymmetry in the form of deceleration)
The presence of Focal and multifocal anomalies (structural, degenerative, metabolic, inflammatory, vascular causes and may develop in neurocutaneous diseases)
If there is a paroxysmal anomaly, its spread, onset, end, type (may occur in epileptic processes and, if obtained, it is useful in the criteria of epilepsy.)
Intermittant photic stimulation (essential in investigating the presence of photosensitive activities), and
The effect of hyperventilation on the EEG Trase will be evaluated and it is useful in the clinical and electrophysiological investigation of some epilepsy cases.
The sleep EEG infants and children who cannot be cooperated in si are being taken, and the evaluation criteria used in this evaluation the same except for hyperventilation and eye opening, although, the right of being evaluated knowing the criteria of the baby and sleep EEG will minimize the delivery of false pathological, or false normal results reports.
What purpose is EEG drawn?
EEG is most commonly used for epilepsy investigations. However, since clinically seizures are not always present and EEG duration is limited, even if epileptic, abnormal EEG may not be found in the interictal ( Inter-seizure) stages and this does not indicate that the case is not epileptic.
The opposite is true; the presence of epileptic activations in EEG in someone who is not clinically fit does not necessarily indicate that the case is epileptic.
EEG is important in epileptic cases, in cases where the clinical and EEG findings match, and it is necessary to follow up the cases diagnosed with epilepsy. In addition, in epileptic cases, EEG will also help in determining seizures, criteria of the case and selection of treatment.
In epileptic cases, focal, multifocal or asymmetric findings in interictal circuits may be a sign of epileptic foci that require the exclusion of structural pathology.
Infection (Herpes encephalitis, subacute sclerosing pan encephalitis, Jakob Creutzfeldt disease), toxic, metabolic (hypoglycemia, hyperglycemia, hepatic encephalopathy, etc.) degenerative, hypoxic (cardio-pulmonary failure, CO intoxication) electrical differences of the brain in encephalopathies lead to diagnosis and prognosis determination.
Some of the disease with behavior problems, enuresis, and situations such as syncope, unexplained and treatment-resistant recurrent clinical situations (treatment-resistant attacks of tachycardia, abdominal pain, attacks of abdominal pain mimicking infantile spasms, etc.) in making the differential diagnosis of epileptic phenomenon, in the study of sleep disorders, EEG can be referenced eat.