title: Olanzapine-induced cerebral metabolic changes related to symptom improvement in schizophrenia.
abstract: The pattern of brain metabolic changes produced by olanzapine has yet to be described, despite the theoretical and clinical interest of this new antipsychotic. We studied a group of 17 schizophrenic patients who underwent two fluoro-deoxyglucose-positron emission tomography (FDG-PET) studies under two different conditions: a baseline scan during treatment with either conventional antipsychotics (n=15) or risperidone (n=2) and a second scan performed 17-24 weeks after switching to olanzapine. PET scans were obtained while performing a standard cognitive paradigm (Continuous Performance Test) and analysed by means of Statistical Parametric Mapping. No significant metabolic changes were found in the comparison between pre- and post-olanzapine conditions. A brain map of the statistical power of our design showed that changes up to 3% in the frontal and up to 8% in the occipital region were not likely to exist (1-beta=0.8). The degree of improvement in positive symptoms was related to the amount of activity decrease in the right orbital region and to the amount of activity increase in the primary visual area. Improvement in negative symptoms was associated with an activity increase in the dorsal prefrontal cortex, and a higher baseline activity in both temporal poles. These correlation patterns suggest that the functional mechanism of action of olanzapine may share traits from both typical and atypical neuroleptics.
authors.affiliation: Department of Psychiatry, Hospital Clínico Universitario, Salamanca, Spain. vmolinarod@wanadoo.es
authors.forename: Vicente
authors.initials: V
authors.lastname: Molina
authors.forename: Juan D
authors.initials: JD
authors.lastname: Gispert
authors.forename: Santiago
authors.initials: S
authors.lastname: Reig
authors.forename: Javier
authors.initials: J
authors.lastname: Pascau
authors.forename: Raúl
authors.initials: R
authors.lastname: Martínez
authors.forename: Javier
authors.initials: J
authors.lastname: Sanz
authors.forename: Tomás
authors.initials: T
authors.lastname: Palomo
authors.forename: Manuel
authors.initials: M
authors.lastname: Desco
mesh_terms: D000328:Adult; D014150:Antipsychotic Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D001569:Benzodiazepines / Q000494:pharmacology* / Q000627:therapeutic use*; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000378:metabolism*; D003071:Cognition; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D000077152:Olanzapine; D049268:Positron-Emission Tomography; D011569:Psychiatric Status Rating Scales; D019275:Radiopharmaceuticals; D012559:Schizophrenia / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology*; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D001569:Benzodiazepines; D000077152:Olanzapine