[A case of large arteriovenous malformation in the frontal lobe complicating attention-deficit/hyperactivity disorder].

We report a 4-year old boy with a large arteriovenous malformation (AVM) exhibiting attention-deficit hyperactivity disorder (AD/HD). He presented with hyperkinesis at the age of 3 years and jacksonian seizure at 3 years 11 months, when he was diagnosed as AVM by cranial computed tomography. Magnetic resonance imaging revealed an AVM of 6 cm in diameter in the left frontal lobe. After 1 year, the AVM developed a varix, and both were surgically removed. We speculate that the prefrontal area was affected by direct compression from AVM and chronic ischemia due to steal phenomenon. Although AD/HD is rarely caused by parenchymal lesions, such as AVM, physicians should carefully investigate causative lesions.