Purpose: To map developing areas of activation with functional magnetic resonance (MR) imaging in sedated children by using passive auditory and visual tasks.
Materials and methods: Forty children between 2 months and 9 years old were examined and grouped according to age. Children were selected from patients referred to undergo brain MR imaging. Patients received pentobarbital (3.0-7.0 mg per kilogram of body weight) or chloral hydrate (50-75 mg/kg). The functional MR imaging study was performed at the end of the examination. Paradigms consisted of flashing lights at 8 Hz displayed on special goggles and a prerecorded mother's voice presented through headphones. Activation maps were obtained from a paired t test with a P value of.0005 (uncorrected).
Results: The visual stimulus produced statistically significant negative values in the rostral aspect of the primary visual area (28 [90%] of 31 patients). The auditory paradigm activated either temporal or frontal areas in 26 (68%) of 31 patients. There was more frontal activation in the older children.
Conclusion: Visual and auditory cortices can be activated in children who have been sedated. Visual responses show negative values in the rostral visual cortex, independent of age. Auditory activation is seen in temporal and frontal lobes.