Which test records electrical activity of the brain by comparing potentials between scalp electrodes and is used to assess seizure activity?

• A. Myelography
• B. Electroencephalography
• C. Venography
• D. Electrocardiography

Answer: (B)

Recording the brain’s electrical activity with electrodes placed on the scalp to evaluate seizures is done through electroencephalography. It measures voltage differences between scalp electrodes, reflecting the combined electrical activity of cortical neurons. In epilepsy assessment, EEG looks for characteristic patterns such as spikes, sharp waves, or spike-and-wave discharges that indicate a propensity for seizures. This test is noninvasive and can be extended over time, sometimes with video to correlate electrical activity with behavior. The other tests—myelography, venography, and electrocardiography—address the spinal canal, veins, and heart, respectively, not brain electrical activity.