Pattern reversal evoked potentials in infantile spasms

Visual evoked potentials in response to sinusoidal gratings of various spatial frequencies, alternating in contrast at 8 Hz were recorded from infants affected by an idiopathic form of infantile spasms (West syndrome). In two infants in whom the spasms began at 3 and 5 months of age, respectively, the VEP's were found to be depressed in amplitude at and around a spatial frequency of 3 and 5 c/deg, respectively. This midfrequency depression, which has never been reported in the literature for normal infants, suggests that infantile spasms in idiopathic patients may interfere at least temporarily with the development of visual function.