Question: EEG on sleep deprived 20 year old results. Hx of right intracerebral bleed and bilateral frontal subdural bleed shortly after birth. Had blilateral burr hole drainage with drainage noted on right side at 3 months of age to drain chronic bilateral subdural effusions. Right side dominant. Backround was composed of symmetric alpha and beta mixed frequencies. Posterior dominant rhythm was moderate amplitude 8-9Hz and better formed on the left hemisphere compared to the right. Hyperventilation with good effort produced no abnormalitiies. Intermittent photic stimulation at various frequencies produced no definite abmormalities, but there was noted to be better photic driving over the left hemisphere. Drowsiness was indicated by slowing of the backround rhythm and loss of muscle artifact. There is no stage II sleep transients noted. Would this be considered a normal or abnormal EEG? Would this be an example of the "breach rhythm"? Could the asymmetric photo driving be due to electrode or light placement?