What common activation procedure can be crucial to revealing absence seizures in an EEG?

Hyperventilation is widely recognized as a common activation procedure that can be particularly effective in revealing absence seizures during an EEG. This technique involves rapid and deep breathing, which can induce a state of cerebral hypercapnia and also influence neuronal excitability. In patients with absence epilepsy, hyperventilation may trigger an absence seizure or enhance the characteristic 3 Hz spike-and-wave discharges that are typically observed during these events.

This procedure is beneficial because absence seizures can be subtle and may not be easily captured without specific triggers. By inducing hyperventilation, the likelihood of observing these seizure patterns increases, making it a valuable tool in the diagnostic process.

Other activation procedures, while sometimes useful, do not have the same established efficacy for exposing absence seizures specifically. For example, although light stimulation can be effective for certain types of seizures, it is not typically associated with absence seizures. Auditory stimulation may have limited utility in this context as well, and while deep breathing can have some effect, hyperventilation's role in triggering or amplifying absence seizures is more prominent and widely accepted in clinical practice.