When is this exam indicated?
Electroencephalography (EEG) and related methods are used in the diagnosis and monitoring of patients with epilepsy or seizures, transient loss of consciousness (to help distinguish syncopal events from true seizures), in neurological diagnostics, and in patients with various acute conditions (coma, disorders of consciousness, dysmetabolic encephalopathies, intracranial hemorrhages, and other neurosurgical emergencies). Other applications are also possible, defined from time to time by the medical specialists.
How is it performed?
EEG is an absolutely non-invasive and painless method. This is the recording of the electrical activity of the brain by means of special electrodes placed on the head, in a manner similar to how it is done to record the electrical activity of the heart in the electrocardiogram with electrodes placed on the chest. In contrast to neuroimaging (CT and MRI), electrodes are simple "sensors" and do not transmit any activity to the human body. EEG recording takes about 20-30 minutes and is performed in a normal outpatient setting. Patient remains seated in a chair or lying in a bed, as appropriate. Special recordings for inpatients or outpatients, sometimes prolonged, are also possible (e.g., dynamic EEG).