Filippi M, Canu E, Gasparotti R, Agosta F, Valsecchi P, Lodoli G, Galluzzo A, Comi G, Sacchetti E
Neuroimaging Research Unit Institute of Experimental Neurology, Division of Neuroscience.
AJNR Am J Neuroradiol. 2014 Jan;35(1):30-7. doi: 10.3174/ajnr.A3583. Epub 2013 Jun 6.
Previous studies have suggested that structural changes do occur in the brain of patients with schizophrenia compared with healthy control participants. However, findings from such studies are inconclusive, probably because of the different methodologic approaches, the clinical heterogeneity of patient samples, and also the fact that patients enrolled were treated with antipsychotic drugs. The aim of this study was to investigate brain GM volumes and intrinsic structural WM changes in first-contact, antipsychotic drug-naïve patients with schizophrenia.
A total of 43 first-contact, drug-naïve, patients with schizophrenia and 17 age-matched control participants were studied. All participants underwent T1-weighted MR imaging and DTI scans. Voxel-based morphometry and tract-based spatial statistics were used to compare GM volumes and WM DTI metrics between groups. MR imaging measures were correlated with the duration of the untreated psychosis and the clinical positive and negative symptoms.
Compared with control participants, patients with schizophrenia showed smaller volumes of the temporal, parietal, and occipital GM, and a pattern of decreased mean diffusivity and increased fractional anisotropy in the brain stem and cerebellum bilaterally, interhemispheric and cortico-cortical connections bilaterally, and right anterior and posterior limb of the internal capsule. In patients, decreased mean diffusivity and increased fractional anisotropy in several brain regions were related to a longer duration of the untreated psychosis and the severity of positive symptoms.
First-contact, drug-naïve, patients with schizophrenia present with volumetric and DTI changes, which correlated with their clinical features. This study increases our knowledge on the neural networks involved in the pathophysiologic mechanisms of schizophrenia.
既往研究表明,与健康对照者相比,精神分裂症患者的大脑确实会发生结构变化。然而,此类研究的结果尚无定论,这可能是由于方法学途径不同、患者样本的临床异质性,以及所纳入的患者接受了抗精神病药物治疗这一事实。本研究的目的是调查首次就诊、未使用过抗精神病药物的精神分裂症患者的脑灰质体积和内在结构性白质变化。
共研究了43例首次就诊、未使用过药物的精神分裂症患者和17例年龄匹配的对照者。所有参与者均接受了T1加权磁共振成像和弥散张量成像扫描。基于体素的形态学测量和基于纤维束的空间统计学方法被用于比较两组之间的灰质体积和白质弥散张量成像指标。磁共振成像测量结果与未治疗精神病的持续时间以及临床阳性和阴性症状相关。
与对照者相比,精神分裂症患者双侧颞叶、顶叶和枕叶灰质体积较小,双侧脑干和小脑、双侧半球间及皮质-皮质连接以及右侧内囊前肢和后肢的平均扩散率降低和各向异性分数增加。在患者中,几个脑区的平均扩散率降低和各向异性分数增加与未治疗精神病的持续时间较长和阳性症状的严重程度相关。
首次就诊、未使用过药物的精神分裂症患者存在体积和弥散张量成像变化,这些变化与其临床特征相关。本研究增加了我们对精神分裂症病理生理机制中所涉及神经网络的认识。