EEG monitoring during paroxysmal hyperpnea of tetralogy of Fallot: an epileptic or hypoxic phenomenon?

We describe a neurologically compromised infant with tetralogy of Fallot who was having multiple paroxysmal episodes of hypotonia, eye rolling, stiffening, and loss of consciousness. Simultaneous electroencephalography with video monitoring was used to determine if these episodes were a primary epileptic phenomenon or the result of hypoxic central nervous system involvement from paroxysms of hyperpnea and cyanosis. The findings would suggest that the paroxysmal episodes were not primarily epileptic. The electroencephalographic findings during the spell were similar to those found with hypoxia due to other causes. This may have physiological and therapeutic significance and be useful in following other infants with congenital heart disease who have similar episodes, especially when the infants have significant risk factors for seizures.