Assessment of cerebral blood volume in schizophrenia: A magnetic resonance imaging study

Department of Pathology and Experimental and Clinical Medicine, Section of Psychiatry, University of Udine, Udine, Italy.
Journal of Psychiatric Research (Impact Factor: 3.96). 10/2007; 41(6):502-10. DOI: 10.1016/j.jpsychires.2006.03.002
Source: PubMed


Brain atrophy has consistently been observed in schizophrenia, representing a 'gross' evidence of anatomical abnormalities. Reduced cerebral blood volume (CBV) may accompany brain size decrement in schizophrenia, as suggested by prior small SPECT studies. In this study, we non-invasively investigated the hemisphere CBV in a large sample of patients suffering from schizophrenia with perfusion-weighted imaging (PWI). PWI images were obtained, following intravenous injection of paramagnetic contrast agent (Gadolinium-DTPA), for 54 DSM-IV patients with schizophrenia (mean age+/-SD=39.19+/-12.20 years; 34 males, 20 females) and 24 normal controls (mean age+/-SD=44.63+/-10.43 years; 9 males, 15 females) with a 1.5T Siemens magnet using an echo-planar sequence (TR=2160 ms, TE=47 ms, slice thickness=5mm). The contrast of enhancement (CE), a semi-quantitative parameter inversely estimating the CBV, were calculated pixel by pixel as the ratio of the maximum signal intensity drop during the passage of contrast agent (Sm) by the baseline pre-bolus signal intensity (So) (CE=Sm/Sox100) for right and left hemisphere on two axial images. Specifically, higher CE values correspond to lower CBV and viceversa Compared to normal controls, patients with schizophrenia had significantly higher bilateral hemisphere CE values (p=0.02) and inverse CE laterality index (p=0.02). This study showed abnormally reduced and inverse hemisphere CBV in a large population of patients with schizophrenia. Hypothetically, chronic low CBV may sustain neural hypoactivation and concomitant increase of free radicals, ultimately resulting in neuronal loss and cognitive impairments. Thus, altered intracranial hemodynamics may accompany brain atrophy and cognitive deficits, being a crucial factor in the pathophysiology of schizophrenia.

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Available from: Paolo Brambilla, May 18, 2015
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    • "An extensive review done by Fusar-Poli et al. (2007) reported notable alterations in brain activation, coupled with decreased performance in respect to controls, and an involvement of various cerebral regions. Perfusion has been found altered in patients with schizophrenia using dynamic susceptibility contrast MRI (Loeber et al., 1999; Brambilla et al., 2007; Bellani et al., 2011; Peruzzo et al., 2011) or arterial spin labeling (Pinkham et al., 2011; Wolf et al., 2012) or positron emission tomography (Faget-Agius et al., 2012). Also patients with "
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    ABSTRACT: Hemodynamic changes in the brain have been reported in major psychosis in respect to healthy controls, and could unveil the basis of structural brain modifications happening in patients. The study of first episode psychosis is of particular interest because the confounding role of chronicity and medication can be excluded. The aim of this work is to automatically discriminate first episode psychosis patients and normal controls on the basis of brain perfusion employing a support vector machine (SVM) classifier. 35 normal controls and 35 first episode psychosis underwent dynamic susceptibility contrast magnetic resonance imaging, and cerebral blood flow and volume, along with mean transit time were obtained. We investigated their behavior in the whole brain and in selected regions of interest, in particular the left and right frontal, parietal, temporal and occipital lobes, insula, caudate and cerebellum. The distribution of values of perfusion indexes were used as features in a support vector machine classifier. Mean values of blood flow and volume were slightly lower in patients, and the difference reached statistical significance in the right caudate, left and right frontal lobes, and in left cerebellum. Linear SVM reached an accuracy of 83% in the classification of patients and normal controls, with the highest accuracy associated with the right frontal lobe and left parietal lobe. In conclusion, we found evidence that brain perfusion could be used as a potential marker to classify patients with psychosis, who show reduced blood flow and volume in respect to normal controls. Copyright © 2015 Elsevier B.V. All rights reserved.
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    • "There is evidence of impaired regional cerebral blood flow in schizophrenia. Most of the reports exploring cerebral perfusion in schizophrenia have been performed with single photon emission computed tomography, showing cerebral hypoperfusion (Andreasen et al., 1992; Vita et al., 1995; Gonul et al., 2003; Brambilla et al., 2007), although not in all studies (Gur et al., 1983). ADMA constricts cerebral blood vessels under resting conditions and inhibits their relaxation in response to acetylcholine (Faraci et al., 1995). "
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    • "± 11.43 years; 31 males, 16 females; all Caucasians) and 29 normal controls (mean age ± S.D. = 45.17 ± 10.41 years; 13 males, 16 females; all Caucasians) were studied (Table 1). This sample represents a subgroup of the one analyzed in a previous work (Brambilla et al., 2007). Seven participants of the original sample were excluded for technical reasons (segmentation process, unsuccessful completion in the post-processing phase). "
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    ABSTRACT: It is still not clear whether brain hemodynamics plays a role in the functional and structural alterations in schizophrenia, since prior imaging studies showed conflicting findings. In this study we non-invasively explored cerebral and cerebellar lobe perfusion in the largest population of participants with schizophrenia thus far studied with perfusion-weighted imaging (PWI). Forty-seven participants affected by schizophrenia and 29 normal controls were recruited. PWI images were acquired following the intravenous injection of a paramagnetic contrast agent. Regional cerebral blood volume (CBV), blood flow (rCBF), and mean transit time (MTT) were obtained with the block-Circulant Singular Value Decomposition (cSVD) for frontal, temporal, parietal, occipital, and cerebellar lobes, bilaterally. Perfusion parameters were separately obtained for both gray and white matter in each lobe. Subjects with schizophrenia showed no significant differences in perfusion parameters when compared with controls. Interestingly, inverse correlations between age at onset and occipital, frontal and cerebellar MTT and between length of illness and frontal CBV were found. Preserved cerebral and cerebellar perfusion in our chronic population may in part be due to the effects of antipsychotic treatment which may have normalized blood volume and flow. Hypoperfusion in relation to chronicity, particularly in the frontal lobe, has been observed in accordance with earlier studies using positron emission tomography.
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