An "after-discharge" can occur on the cortical EEG recording after what event?

An "after-discharge" on a cortical EEG recording is recognized as a prolonged electrical activity that follows a brief period of stimulation. In the context of the given question, electrical stimulation of the exposed cortex is the event that can induce such after-discharges.

When electrical stimulation is applied to the cortex, it can excite the neurons, potentially leading to a wave of depolarization across the cortical surface. Following this stimulation, the neurons may remain in a hyper-excitable or excitable state for a brief period, resulting in additional electrical activity that continues even after the stimulation has ceased. This is characterized in the EEG as an after-discharge. Clinically, this is significant as it can relate directly to potential functional changes in the brain and help assess the risk of post-surgical complications such as seizures.

While seizures can also lead to after-discharges as a part of the seizure activity itself, the term typically refers to the specific phenomenon following a direct electrical stimulus. Other options, such as 60 Hz artifact, relate to interference in the signal and do not represent true physiological cortical responses. Electrocautery, while it may generate electrical noise and disrupt the EEG temporarily, does not typically produce after-discharges in the same manner as