How does hyperventilation affect an EEG?

Hyperventilation is a technique often used during EEG recordings that can significantly influence the brain's electrical activity. When a person hyperventilates, they reduce the levels of carbon dioxide (CO2) in their blood, leading to respiratory alkalosis. This physiological change can have several effects on brain excitability and activity.

One of the key outcomes of hyperventilation is its potential to induce seizures in individuals who are predisposed to them, particularly in those with epilepsy. The reduction in CO2 can lead to a range of downstream effects in brain function, potentially increasing neuronal excitability. This increased excitability can manifest as changes in EEG waveforms, including the appearance of spikes or seizure discharges, and can induce various types of seizure activities.

In addition to inducing seizures, hyperventilation can also alter the baseline EEG rhythm, leading to a variety of other changes in brain wave patterns. Therefore, being aware of the effects of hyperventilation on EEG readings is crucial for accurate interpretation and diagnosis during EEG studies.