Abnormal Temporal Lobe Metabolism in Violent Subjects: Correlation of Imaging and Neuropsychiatric Findings

PURPOSE To search for metabolic correlates of clinical and electrophysiological abnormalities in violent subjects. METHODS Seven subjects with histories of extremely violent behavior were studied with positron emission tomography (PET) with fludeoxyglucose F 18 (FDG), brain electrical area mapping, MR imaging, neuropsychiatric and neuropsychological testing, and clinical examination during medical evaluation associated with legal proceedings. Nine control subjects without evidence of organic brain disease were also studied with FDG-PET. Quantitative PET data were calculated as standardized uptake values comparing the highest occipital region with the lowest temporal region. RESULTS Temporal lobe metabolism was decreased in the study group relative to the control subjects. Medial temporal lobe metabolism was 39% lower than that in the occipital cortex in study subjects and only 27% lower than that in control subjects. These groups differed by Mann-Whitney U test and Wilcoxon9s two-sample test. Metabolic differences correlated with limbic neuropsychiatric and electrophysiological abnormalities in the violent group. CONCLUSION In this selected population of violent subjects, FDG-PET scans showed metabolic abnormalities in the temporal lobes. These abnormalities correlated with limbic abnormalities seen at electrophysiological and neuropsychiatric evaluation.