This Article  • Full text  • PDF  • Reply to article  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Citation map  • Citing articles on ISI (27)  • Contact me when this article is cited  Related Content  • Similar articles in this journal  Topic Collections  • Schizophrenia  • PET/ SPECT Imaging  • Alert me on articles by topic

A Positron Emission Tomographic [¹⁸F]Fluorodopa Study

Stephen McGowan, MRCPsych; Andrew D. Lawrence, PhD; Tim Sales, MRCPsych; Digby Quested, MRCPsych; Paul Grasby, MD, MRCPsych

Arch Gen Psychiatry. 2004;61:134-142.

Context  The dopamine overactivity hypothesis of schizophrenia remains one of the most influential theories of the pathophysiology of the illness. Radiotracer brain imaging studies are now directly testing aspects of the overactivity hypothesis.

Objective  To assess presynaptic dopaminergic function in a large cohort of patients with schizophrenia by means of [¹⁸F]fluorodopa uptake and a high-sensitivity 3-dimensional positron emission tomograph. We predicted elevations in striatal [¹⁸F]fluorodopa uptake and reductions in prefrontal cortical [¹⁸F]fluorodopa uptake in patients with schizophrenia.

Design  Case-control study.

Setting  Research institute investigation recruiting hospital outpatients.

Patients  Sixteen male medicated hospital outpatients with a DSM-IV diagnosis of schizophrenia (mean age, 38 years) and 12 age-matched male volunteers free of psychiatric and neurologic illness.

Intervention  [¹⁸F]fluorodopa positron emission tomographic scanning.

Main Outcome Measure  [¹⁸F]fluorodopa uptake constant K_i measured with statistical parametric mapping and region-of-interest analyses.

Results  Statistical parametric mapping (P<.05 corrected) and region-of-interest analyses (P<.01) showed increased [¹⁸F]fluorodopa uptake, confined primarily to the ventral striatum in patients with schizophrenia. No reductions in prefrontal cortical [¹⁸F]fluorodopa uptake K_i were seen in the statistical parametric mapping and region-of-interest analyses, although dorsal anterior cingulate [¹⁸F]fluorodopa K_i correlated with performance on the Stroop Color-Word Test in both groups.

Conclusions  As in studies in unmedicated patients, presynaptic striatal dopamine dysfunction is present in medicated schizophrenic patients, adding further in vivo support for dopamine overactivity in the illness.

From the Cyclotron Unit, Medical Research Council Clinical Sciences Centre, Hammersmith Hospital, Imperial College, London, England (Drs McGowan and Grasby); Medical Research Council Cognition and Brain Sciences Unit, Cambridge, England (Dr Lawrence); and University Department of Psychiatry, Warneford Hospital, Headington, Oxford, England (Drs Sales and Quested).