REGIONAL CEREBRAL BLOOD-FLOW AND NEGATIVE POSITIVE SYMPTOMS IN 24 DRUG-NAIVE SCHIZOPHRENICS

SPECT/PET studies in schizophrenia revealed inconsistent changes of re gional cerebral blood flow (rCBF). Frontal hyperperfusion as well as h ypoperfusion are described. This study was undertaken to investigate t he relations between rCBF, psychopathology according to PANSS and effe cts of neuroleptic therapy. Methods: Twenty-four drug-naive acute pati ents with a first manifestation of schizophrenia were examined with Tc -99m-HMPAO brain SPECT and assessed according to PANSS. Of these, 22 w ere controlled again after neuroleptic treatment. Following attenuatio n correction, region-to-cerebellar count ratios were obtained from 98 irregular regions of interest drawn in all slices (6.25 mm). The ratio s were compared to 20 control subjects, and changes lying outside of 2 s.d. were considered abnormal. Results. In different drug-naive patie nts, hyperperfusion as well as hypoperfused patterns were found. In dr ug-naive patients, the seven subscores of positive symptoms (pos 1-7) in PANSS showed different correlations to rCBF: Formal thought disorde rs (pos 2) and grandiosity (pos 5) were positively correlated to bifro ntal and bitemporal rCBF (r = +0.59 to +0.70). Delusional ideas (pos 1 ), hallucinatory behavior (pos 3) and suspiciousness (pos 6) demonstra ted a negative correlation to bifrontal, cingulate, left temporal and left thalamic rCBF (r = -0.59 to -0.66). Stereotyped ideas (neg 7) as a negative symptom showed a negative correlation to left frontal, left temporal and left parietal rCBF (r = -0.59 to -0.65). No correlations were found between residual positive symptoms and rCBF after neurolep tic treatment and clinical improvement, but all negative symptoms (neg 1-7) had a negative correlation to bifrontal, bitemporal, cingulate, basal ganglia and thalamic rCBF (r = -0.59 to -0.74). Conclusion: Our results illustrate that different positive symptoms are accompanied by different rCBF values: some induce hyperperfusion, others hypoperfusi on. After therapy (and reduction of positive symptoms), only negative symptoms correlate exclusively to hypoperfusion. This may be the cruci al factor in explaining inconsistencies of past results in perfusion p attern in drug-naive schizophrenic patients.