HYPOFRONTALITY IN SCHIZOPHRENIA - INFLUENCE OF NORMALIZATION METHODS

1. Studies with Single Photon Emission Computed Tomography (SPECT) in schizophrenia research have utilized different approaches to normaliza tion of data, such as cerebellar ratio and whole brain ratio methods, leading to conflicting findings. 2. The authors compared these two met hods to test the hypofrontality hypothesis of schizophrenia. 3. Eighte en chronic and medicated DSM-TV schizophrenic patients and 10 healthy controls underwent two SPECT examinations using Tc-99m-HMPAO as a trac er at baseline and during frontal activation while applying the Wiscon sin Card Sorting Test. 4. The hypofrontality hypothesis was supported with both indexes of relative perfusion, although the whole brain rati o method appeared to be more reliable and specific than the cerebellar ratio method. 5. Further studies are required to confirm these prelim inary results on the specificity and sensitivity of both methods.