Why might a patient be instructed to hyperventilate during an EEG?

Hyperventilation is a specific technique used during an EEG to potentially trigger seizure activity for diagnostic purposes. This is particularly relevant in the context of epilepsy, where the goal is to provoke and capture abnormalities in brain activity that may not be present during a standard EEG. When a patient hyperventilates, it leads to changes in blood flow and the carbon dioxide levels in the body, which can sometimes provoke seizures or other abnormal brain wave activity that can be observed on the EEG.

This method is a common practice in epilepsy monitoring, as it helps identify the patient's seizure threshold and the types of seizures they may experience. The induced state can provide crucial information for diagnosis and treatment planning.

In contrast, while managing anxiety or promoting relaxation can be beneficial in a clinical setting, they are not the primary reasons for instructing a patient to hyperventilate during an EEG. Stabilizing brain activity is also not aligned with the purpose of hyperventilation, as the goal is to observe dynamic changes rather than stabilize the current state.