REGIONAL CEREBRAL BLOOD-FLOW CHANGES ASSOCIATED WITH RISPERIDONE TREATMENT IN ELDERLY SCHIZOPHRENIA-PATIENTS - A PILOT-STUDY

Although there is evidence that some schizophrenia patients may have a ltered regional cerebral blood flow patterns, few studies have address ed the relationship between cortical activity and changes in psychiatr ic symptoms following treatment, particularly in the elderly. We took advantage of an existing safety and tolerance study of risperidone in the elderly and examined the possible relationship between changes in psychiatric symptoms following risperidone and changes in relative cor tical perfusion in a group of 6 elderly schizophrenia patients. All su bjects were at least 65 years old and diagnosed with schizophrenia acc ording to DSM-III-R criteria. The patients were assessed using the Pos itive and Negative Syndrome Scale for Schizophrenia (PANSS) and Mini-M ental Status Examination (MMSE) and had single photon emission compute d tomography (SPECT) studies before and at least 3 weeks after change of their previous neuroleptic Po risperidone. The frontal/total cortex and temporal/total cortex counts in the slice ratios, and 99mTechniti um-hexamethylpropylene amine oxime (99mTc-HMPAO) percentage uptake in the whole cortical area in the slice were used for data analysis. With risperidone, patients (age 66-81) scored better on the PANSS, particu larly in the positive symptom subtests. The changes in positive sympto m scores correlated directly with those in frontal and temporal relati ve activity and 99mTc-HMPAO percentage uptake in the whole cortical ar ea in the slice. Our findings suggest that the improvement in psychoti c symptoms after risperidone is associated with a decrease in frontal and temporal activity and a reduction in 99mTc-HMPAO percentage uptake in the entire cortical area in the slice and agree with data from you nger populations. Comparative studies assessing the therapeutic impact of neuroleptics on cortical activity in different age groups could be helpful in examining both the mechanisms of action of various drugs a nd the links between symptoms and specific brain areas.