Interictal discharges in patients with complex partial seizures are most likely to be recorded in the EEG?

Interictal discharges in patients with complex partial seizures are most commonly observed during stage-1 sleep. This is because the brain's electrical activity changes with different states of consciousness, and certain types of discharges can become more prominent during sleep. In stage 1 sleep, the brain is transitioning from wakefulness to sleep, and the EEG is characterized by slower waveforms and increased synchronicity of brain activity, which can enhance the visibility of interictal discharges associated with epilepsy.

While interictal discharges can be present during wakefulness, they are often less pronounced compared to those seen in sleep. Photic stimulation may not reliably evoke these discharges, as it’s more useful for identifying photosensitive epilepsy. REM sleep is typically dominated by different brain wave patterns characterized by increased irregular activity that may obscure the interictal discharges typically seen in the earlier sleep stages. Therefore, stage-1 sleep presents the most favorable conditions for the recording of interictal discharges in patients with complex partial seizures.