The effect of clozapine on neuroimaging findings in schizophrenia.
Functional and structural neuroimaging help us to compare the brains of schizophrenic patients and controls, moreover they let us observe the changes with treatment. Longitudinal studies comparing patients with typical and atypical antipsychotics have been useful in understanding the effects of these antipsychotic medications on brain function. In general, atypical antipsychotics are suggested to have greater normalizing effects on brain function than typical, although the results are controversial. In particular, clozapine appears to act more selectively than typical antipsychotics on the prefrontal region, an area of special relevance in higher cognitive functions and schizophrenia. The study of anatomic and functional brain variables associated with clozapine response in schizophrenia may help to identify patients who are most likely to benefit from clozapine treatment. We investigated the effect of clozapine on regional cerebral blood flow and (1)H MRS findings and studied their relationship with treatment response. Clozapine increased frontal/basal ganglia perfusion ratio in treatment-responders. In addition, NAA/Cre ratio has increased and Cho/Cre has decreased in dorsolateral prefrontal cortex after 8 weeks of clozapine treatment. The results of the study will be discussed in the light of current literature. These findings can contribute to better understanding of mechanism of action of clozapine.
Ertugrul
Aygun
A
Department of Psychiatry, Hacettepe University Faculty of Medicine, Ankara, Turkey. aertugru@hacettepe.edu.tr
Uluğ
Berna
B
D000369:Aged, 80 and over; D014150:Antipsychotic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001921:Brain / Q000098:blood supply / Q000187:drug effects*; D002794:Choline / Q000378:metabolism; D003024:Clozapine / Q000009:adverse effects / Q000627:therapeutic use*; D003401:Creatine / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D009483:Neuropsychological Tests; D011379:Prognosis; D011569:Psychiatric Status Rating Scales; D012039:Regional Blood Flow / Q000187:drug effects; D012559:Schizophrenia / Q000175:diagnosis / Q000188:drug therapy*; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome
D014150:Antipsychotic Agents; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003024:Clozapine; D003401:Creatine; D002794:Choline