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| Conclusion | ||||||
| In view of the above presented results, This study adds to the growing literature that supports the presence of abnormalities in regional cerebral blood flow in patients who are suffering from schizophrenia. To our knowledge, this is the first study in the literature to use regional cerebral blood flow with an identical experimental design on chronically ill, neuroleptic-naive patients and who were assessed after a 6 months medication washout period. | ||||||
| Since earlier SPECT studies has reported multiple contradictory results regarding cerebral perfusion in neuroleptic-naive patients, raising the possibility that regional cerebral blood flow abnormalities may take the form of hypoperfusion, hyperperfuison or in other studies even no change. Also, the effect of neuroleptic treatment on regional cerebral blood flow, thus showing regional cerebral blood flow as a state marker this study provides a crucial test of all these possibilities. Previous studies of neuroleptic-naive patients conducted to date have examined only the resting condition or have used cognitive challenges in very small samples, and they have not compared neuroleptic-naive patients results with post treatment results. | ||||||
| Through the use of the present experimental design, we have shown that hypofrontality is probably not a long- term effect of neuroleptic treatment. In fact, hypofrontality was present most prominently in the neuroleptic-naive patients.. Thus, these results appear to suggest that hypoperfusion is a primary problem in schizophrenia, rather than secondary to either long-term treatment or chronicty of illness. | ||||||
| A second major finding in this study is the relationship between hypoperfusion, and the presence of negative symptoms. Thus, the negative symptoms were not secondary to medication effects and can therefore be considered as 'primary negative symptoms'. | ||||||
| We conclude that: | ||||||
| 1- Schizophrenia is more like to be a heterogonous syndrome rather than a continuum of symptoms, negative correlations obtained between different clusters of symptoms and regions of interest supports this assumption. | ||||||
| 2- The frontal, left temporal, left parietal lobes and basel ganglia are the most vulnerable areas in demonstrating hypoperfusion, thus supporting the theory of circuits were more than theories suggesting localized and discrete lesions. | ||||||
| 3- The linkage of left-hemisphere hypofrontality to right-hemisphere hypofrontality function is interesting, since it displays a more prominent dysfunction in two different regions that are likely to be activated simultaneously at the same time. | ||||||
| 4- SPECT brain perfusion imaging is valuable and sensitive for the evaluation of cerebral perfusion changes following neuroleptic treatment, thus, to a limit, it can be considered as a state marker for positive symptoms. | ||||||
| 5- The changes detected in our study can contribute in explaining the components of the patient's symptoms in the absence of morphological abnormalities using other imaging modalities. | ||||||