Prevalence of brain arteriovenous malformation ranges from 0.14% to 0.6% according to various estimates. A large number of these patients remain asymptomatic. The most common presentation is due to brain hemorrhage. A 14-year-old girl presented to the pediatrician with erratic behavior issues and hallucinations. She was diagnosed by the pediatrician and mental health facility as having schizophrenia and bipolar disorder. Once she was transferred to our children's hospital, evaluation by a pediatric neurologist, computed tomography scan, magnetic resonance imaging, and laboratory workup including lumbar puncture confirmed a clinically isolated syndrome and frontal lobe arteriovenous malformation. Frontal lobe lesions including arteriovenous malformation in the frontal lobe can cause psychological symptoms and behavioral issues. We also discuss the differential diagnosis of acute demyelinating syndromes.