Reduced fractional anisotropy of corpus callosum in first-contact, antipsychotic drug-naive patients with schizophrenia.
Articolo
Data di Pubblicazione:
2009
Abstract:
Background: Corpus callosum is the most important commissure of the brain and therefore
represents a first-choice candidate to challenge hypotheses of disrupted inter-hemispheric
connectivity and white matter pathology in patients with schizophrenia. Recent studies on
diffusion tensor imaging (DTI) of corpus callosum yielded promising but equivocal evidence of
reduced fractional anisotropy (FA) in schizophrenia patients who were, for the most part,
chronic cases on medication for a lengthy period of time. To exclude potentially confounding
effects of the course of the disorder and its treatment, we compared callosal FA of first-contact,
antipsychotic drug-naive schizophrenia patients (n=21) and healthy controls (n=21).
Methods: Splenium and genu FA were obtained by two independent observers utilizing large,
rectangular, tractography-guided regions of interest outlined on directional color-coded maps.
Inter-observer agreement on FA was evaluated by means of the Bland and Altman and the
Passing and Bablok procedures together with an estimate of the intra-class correlation
coefficient.
Results: Strong inter-observer agreement of FA values emerged from each of the three statistical
approaches utilized. ANCOVA showed a significant effect on FA for the interaction between
patient–control membership and callosal region (F=5.354; p=0.026); post hoc multiple
comparisons demonstrated that, when compared to the controls, the patients had lower mean
FA values (p=0.005) in the splenium but not in the genu and that this difference tended to be
more evident in males (p=0.090).
Conclusions: Lowered mean FA values in the splenium of first-contact, antipsychotic drug-naïve
patients with respect to healthy controls strongly support the hypothesis that processes
operant at least since the earliest phases of the disorder and independent from exposition to
antipsychotic drugs contribute to reduced anisotropy in schizophrenia.
represents a first-choice candidate to challenge hypotheses of disrupted inter-hemispheric
connectivity and white matter pathology in patients with schizophrenia. Recent studies on
diffusion tensor imaging (DTI) of corpus callosum yielded promising but equivocal evidence of
reduced fractional anisotropy (FA) in schizophrenia patients who were, for the most part,
chronic cases on medication for a lengthy period of time. To exclude potentially confounding
effects of the course of the disorder and its treatment, we compared callosal FA of first-contact,
antipsychotic drug-naive schizophrenia patients (n=21) and healthy controls (n=21).
Methods: Splenium and genu FA were obtained by two independent observers utilizing large,
rectangular, tractography-guided regions of interest outlined on directional color-coded maps.
Inter-observer agreement on FA was evaluated by means of the Bland and Altman and the
Passing and Bablok procedures together with an estimate of the intra-class correlation
coefficient.
Results: Strong inter-observer agreement of FA values emerged from each of the three statistical
approaches utilized. ANCOVA showed a significant effect on FA for the interaction between
patient–control membership and callosal region (F=5.354; p=0.026); post hoc multiple
comparisons demonstrated that, when compared to the controls, the patients had lower mean
FA values (p=0.005) in the splenium but not in the genu and that this difference tended to be
more evident in males (p=0.090).
Conclusions: Lowered mean FA values in the splenium of first-contact, antipsychotic drug-naïve
patients with respect to healthy controls strongly support the hypothesis that processes
operant at least since the earliest phases of the disorder and independent from exposition to
antipsychotic drugs contribute to reduced anisotropy in schizophrenia.
Tipologia CRIS:
1.1 Articolo in rivista
Elenco autori:
Gasparotti, Roberto; Valsecchi, Paolo; Carletti, F; Galluzzo, A; Liserre, R; Cesana, Bruno Mario; Sacchetti, Emilio
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