Intracarotid amobarbital testing for language and memory dominance in children

The intracarotid amobarbital procedure (IAP) was attempted in 22 pediatric epilepsy surgery candidates, ages 5-12 years old. With extra pre-test teaching and emotional preparation, adjusted amobarbital dosage for younger patients, and simplified test items tailored to the child's abilities, language and memory testing were accomplished after at least one injection for 19 (86%) of patients. Language dominance was clarified in 11 children overall (50% of patients), in all of the children who had bilateral testing and at least borderline intelligence (IQ > 70), and in 57% of the children with mild or moderate mental retardation. Memory assessment was accomplished in 18 children after amobarbital injection of the hemisphere ipsilateral to the predominant epileptogenic zone. IAP retention scores tended to be lower in children than adults, especially in the setting of mental retardation. Retention scores after ipsilateral injection were > 60% in all 10 of the children with at least borderline intelligence, but < 60% (25-50%) in five of eight children with mental retardation. Retention scores after contralateral injection were > 60% in only four of 12 children. Our results suggested that a modified pediatric IAP protocol can clarify the hemisphere of language dominance in most verbal preadolescent children with at least borderline intelligence, and in many children with mental retardation. However, IAP memory retention scores tended to be lower in children than adults and should be interpreted with caution.