| 其他摘要 | Neurological soft signs (NSS) are traditionally defined as minor non-localizable neurological abnormalities. Another unclear issue of NSS is whether it is the “trait marker” of schizophrenia. Nowadays, studies have found that patients with bipolar disorder have also showed significantly higher prevalence of NSS than healthy controls. In this dissertation, we conducted four experiments to examine these issues systematically. In study one, we examined the prevalence of NSS in a total of 120 participants, with 30 participants in each group of schizophrenia, bipolar disorder, major depression, healthy controls. We used Analysis of Variance (ANOVA) and discriminant analysis to test the specificity prevalence of NSS among the four groups. ANOVA analysis showed that both patients with schizophrenia and bipolar disorder but not major depression showed significantly higher NSS than healthy controls. The discriminant analysis showed that the NSS discriminant power was about 70% to 90%. In study two, we conducted an Activation Likelihood Estimation (ALE) meta-analysis of the brain imaging studies of NSS. Seven structural Magnetic Resonance Imaging (sMRI) studies and 14 functional Magnetic Resonance Imaging (fMRI) studies of NSS were included in the final ALE analysis according to a set of rigorous inclusion and exclusion criteria. The results of the ALE showed that the left cerebellum,left pre-central gyrus (BA6) and some other brain regions may the brain location of NSS. In study three, we examined the structural neural basis of NSS in patients with psychotic disorders. Eight patients with schizophrenia, 16 patients with bipolar disorder, 17 patients with major depression and 26 healthy controls were recruited for the structural brain scan. We used the Voxel-Based Morphometry (VBM) analysis from SPM8. Negative correlation of NSS and brain structures were demonstrated across the four groups. These brain regions included the temporal lobe, the prefrontal lobe, the pre- and post-central gyrus, the parahippocampal gyrus and the culmen of cerebellum. In study four, we investigated the neural basis and activation of a motor coordination signs, namely the “fist-edge-palm” signs in the same participants from study 3. We administered an imaging paradigm analogue to the “fist-edge-palm” task. Findings showed that patients with major depression only demonstrated hypo-activity in the parahippocampal gyrus, cerebellum and the insular as compared to healthy controls. On the other hand, patients with bipolar disorder demonstrated a wider neural abnormalities of brain activation in the cingulate gyrus, the temporal gyrus, the prefrontal gyrus as compared to healthy controls. Patients with schizophrenia showed significantly hyper-activity in the caudate, insular, and cingulate gyrus as compared to healthy controls. Taken together, the current findings suggested that NSS might not be only limited to patients with schizophrenia but also patients with bipolar disorders. Neuroimaging findings showed that NSS were associated with both structural and functional brain abnormalities in patients with psychotic disorders, with patients with schizophrenia showing significantly more severe impairments in brain structures and functional activation. Brain regions associated with NSS included the temporal lobe, the prefrontal lobe, the cerebellum, the pre- and post- central lobe, parahippocampal gyrus, thalamus and cingulate gyrus. |
修改评论