Which substance is primarily measured upon launching an EEG during seizure episodes?

During seizure episodes, the primary focus of an EEG is on measuring electrical activity in the brain. Seizures are characterized by abnormal bursts of electrical discharges, which can be detected and recorded through electrodes placed on the scalp. This electrical activity reflects the brain's functioning during a seizure, providing crucial information regarding the type, duration, and localization of the seizure.

While other physiological parameters such as oxygen levels, carbon dioxide levels, and blood glucose levels are important in the overall assessment of a patient, they do not directly relate to the specific electrical changes that the EEG is designed to measure. The EEG provides real-time insights into the brain's electrical patterns, making it an essential tool for diagnosing and understanding seizure activity.