Hemispheric language dominance in 12 children with slow growing tumors near left hemisphere language areas was studied at the Cleveland Clinic, OH. Complex partial seizures began at or under 6 years of age. Tumor resection was performed at ages 5 to 20 years, an average of 8 years after seizure onset. Neurologic exam was normal in 11 patients. Ten (83%) had amobarbital tests indicating left hemisphere language dominance, confirmed by cortical stimulation in 6. Eleven with complete tumor resection were seizure-free at follow-up. Most had developmental neoplasms, often congenital. Paired t tests found no differences between pre- and postoperative performance of language tests, and a tendency for improved language function after operation. 
COMMENT. Language dominance does not usually transfer to the contralateral hemisphere in young children with low-grade left frontal and temporal tumors. Successful tumor resection is accomplished by using cortical stimulation studies and sparing of the language areas in close proximity to the tumor.