Elektroensefalografi (EEG) Nörofizyolojisi
Özet
Elektroensefalografi (EEG), beyindeki nöronların elektriksel aktivitelerini saçlı deriye yerleştirilen elektrotlar aracılığıyla kaydeden ve sinir sistemini etkileyen hastalıkların tanısında kullanılan bir nörofizyolojik yöntemdir. Bu işlemde membran potansiyelleri, aksiyon potansiyelleri ve postsinaptik potansiyeller gibi hücresel mekanizmalar temel alınarak beynin voltaj farkları grafiksel olarak temsil edilir. EEG çekiminde standart 10-20 elektrot sistemi ve çeşitli montajlama teknikleri (bipolar, referans vb.) kullanılarak alfa, beta, teta ve delta gibi beyin ritimleri ile paroksismal aktiviteler analiz edilir. Ayrıca tetkik sırasında anormallikleri ortaya çıkarmak için hiperventilasyon, fotik uyarı ve uyku gibi aktivasyon prosedürlerinden yararlanılırken, dış kaynaklı veya biyoelektrik kökenli artefaktların doğru ayırt edilmesi klinik yorumlama açısından kritik önem taşır.
Electroencephalography (EEG) is a neurophysiological method that records the electrical activities of neurons in the brain through electrodes placed on the scalp and is used in the diagnosis of diseases affecting the nervous system. Based on cellular mechanisms such as membrane potentials, action potentials, and postsynaptic potentials, the voltage differences of the brain are represented graphically. In EEG recordings, brain rhythms such as alpha, beta, theta, and delta, as well as paroxysmal activities, are analyzed using the standard 10-20 electrode system and various montage techniques (bipolar, reference, etc.). Additionally, activation procedures like hyperventilation, photic stimulation, and sleep are utilized to reveal abnormalities, while the correct identification of external or bioelectrical artifacts is critical for clinical interpretation.
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