Association between global visual scanning and cognitive function in schizophrenia.

OBJECTIVE: Abnormalities of global visual scanning have been well-recognized in schizophrenia patients. However, its relevance to various cognitive domains is still understudied. In the present study, we identified the association between global visual scanning and cognitive function in schizophrenia. METHODS: Eye movement was captured and analyzed in 28 individuals with schizophrenia and 21 healthy controls in free viewing test. The MATRICS consensus cognitive battery (MCCB) was applied to evaluate cognitive function. RESULTS: Consistent with previous reports, schizophrenia patients exhibited several eye movement abnormalities during global visual scanning and showed cognition deficits in MCCB test as compared with healthy controls. Fixation duration was significantly related to cognitive dysfunction in schizophrenia. Moreover, there was a potential that eye movement measures during landscape scanning, rather than face scanning, were preferentially related to cognitive dysfunction. CONCLUSION: This study indicated the association between free visual scanning and various cognitive functions in schizophrenia, shedding light on the possibility that some eye movement measures during visual exploration could be a biomarker for cognitive deficits in schizophrenia.

The relationship between resting electroencephalogram oscillatory abnormalities and schizotypal personality traits in the first-degree relatives of schizophrenia patients.

Although a large amount of studies have manifested resting state electroencephalogram oscillatory abnormalities in schizophrenia and their first-degree relatives and in schizotype, the results are far from consistent and no research found any relationship between electroencephalograph (EEG) abnormalities and schizotypal personality in first-degree relatives. The present study is to verify the modifications of EEG power spectra in eyes-open resting state of schizophrenia and first-degree relatives, and to investigate associations between EEG band power and schizotypal personality traits in first-degree relatives of schizophrenia patients. Participant samples in this study consisted of 33 healthy normal controls, 35 unaffected first-degree relatives of schizophrenia patients and 35 schizophrenia patients. Group differences in resting EEG band power were examined via repeated-measures analysis of variance, and correlation between EEG power and schizotypal personality traits via Pearson Correlation analysis. The results showed that patients with schizophrenia exhibited increased delta, theta and alpha activity over anterior and central regions in eyes-open resting state compared with that of normal control. Gamma band power was found for the first time to be negatively correlated to schizotypal personality traits in first-degree relatives of schizophrenia patients. To conclusion, these findings suggested that low-frequency EEG activity might be neural manifestations of pathophysiological changes in the brain of schizophrenia, and gamma band activity might be an approach to measure the genetic liability of the disorder.

Neuroprotective Effect of Modified Electroconvulsive Therapy for Schizophrenia: A Proton Magnetic Resonance Spectroscopy Study.

The underlying mechanism of modified electroconvulsive therapy (MECT) treatment for drug-resistant and catatonic schizophrenia remains unclear. Here, we aim to investigate whether MECT exerts its antipsychotic effects through elevating N-acetylaspartate (NAA) concentration measured by proton magnetic resonance spectroscopy (H-MRS). Multiple-voxel H-MRS was acquired in the bilateral prefrontal cortex (PFC) and thalamus to obtain measures of neurochemistry in 32 MECT, 34 atypical antipsychotic-treated schizophrenic patients, and 34 healthy controls. We found that both MECT and atypical antipsychotic treatments showed significant antipsychotic efficacy. MECT and atypical antipsychotic treatments reversed the reduced NAA/creatine ratio (NAA/Cr) in the left PFC and left thalamus in schizophrenic patients compared with healthy controls. Furthermore, the NAA/Cr ratio after treatments was significant higher in the MECT group, but not in the medication group. Our findings demonstrate that eight times of MECT elevated the relative NAA concentration to display neuroprotective effect, which may be the underlying mechanism of rapid antipsychotic efficacy.

A longitudinal study on intrinsic connectivity of hippocampus associated with positive symptom in first-episode schizophrenia.

Hippocampal pathology has been considered to underlie clinical, functional and cognitive impairments in schizophrenia. While longitudinal magnetic resonance imaging (MRI) studies have demonstrated progressive gray matter reduction of the hippocampus during the early phases of schizophrenia (SCZ), very little is known about whether functional connectivity (FC) between the hippocampus and other brain regions also exhibit progressive changes. In this study, resting state functional MRI (fMRI) was used to examine changes in hippocampal connectivity at baseline and follow-up scans comparing 68 patients with first episode SCZ and 62 matched controls. At baseline and follow-up, in the bilateral hippocampal network, SCZ mainly showed decreased FC with bilateral cerebellum posterior lobe, frontal gyrus temporal gyrus, precuneus, and cingulate cortex compared to controls. Furthermore, in the bilateral hippocampus, there was a significant interaction effect of group and time for FC with cerebellum posterior lobe, temporal gyrus, frontal gyrus, and posterior cingulate cortex. Interestingly, longitudinal changes of bilateral hippocampal connectivity with right middle frontal gyrus negatively correlated with positive symptom scores in SCZ. These results provide novel evidence for the progressive changes of FC between hippocampus and other brain regions in SCZ. It further suggests that longitudinal changes of bilateral hippocampal connectivity with right middle frontal gyrus can contribute to the formation and emergence of positive symptom of SCZ.

[Effectiveness and safety of high dose transcranial magnetic stimulation in schizophrenia with refractory negative symptoms: a randomized controlled study].

OBJECTIVE: To evaluate the efficacy and safety of high dose transcranial magnetic stimulation (rTMS) in patients with schizophrenia with refractory negative symptoms. METHODS: From January 2013 to April 2014 at our institute, 70 hospitalized patients of schizophrenia, according to the diagnostic criteria of Diagnostic and Statistical Manual of Mental Disorders-4th Edition (DSM-IV), aged from 18 to 45 were randomly divided into study group (n = 33) and control group (n = 37). Both kinds and dosages of antipsychotics were preserved as before. All patients were treated with 10 Hz rTMS. rTMS was delivered to the left dorsolateral prefrontal cortex (DLPFC) with a figure-eight solid core coil at 100% motor threshold, 2 times daily for 10 days within 2 weeks. Sham stimulation was used in control group. In both groups, Positive and Negative Syndrome Scale (PANSS) and Treatment Emergent Symptom Scale (TESS) were used to evaluate the efficacy and safety before treatment, at week 1 and week 2, and subjective visual analogue scale (VAS) score was checked after each rTMS session. PANSS was performed 3 times at followup visits of week 4, week 8 and week 12. RESULTS: Compared with before treatment the total score of PANSS and the score of negative symptoms at week 2 declined in study group (q = 3.780, 4.258, P < 0.05), especially the factors of blunted affect, emotional withdrawal and passive/apathetic social withdrawal (q = 3.829, 4.089, 4.072, P < 0.05). At the follow-up of week 4, week 8 and week 12 after treatment, none of the above factors got significant changes in study group (P > 0.05). After 2 weeks' treatment, the effective rates were 43.75% and 11.43% in study group and control group, respectively, and there was a significant difference between two groups (X2 = 8.888, P =0.003). The incidence of headache in study group was higher than that in control group(37.50% vs 8.57%, χ2 = 8.051, P = 0.005). The highest score of pain was (49 ± 14) in study group, which occurred after the first rTMS treatment. Along with the treatment, the score gradually become lower, and the lowest was (11 ± 5) after 20th treatment. CONCLUSION: Among schizophrenia patients with refractory negative symptoms, 10 Hz rTMS applied 2 times daily within 2 weeks is effective and safe, especially, may improve blunted affect, emotional withdrawal and passive/apathetic social withdrawal.

Atypical antipsychotic drug treatment for 6 months restores N-acetylaspartate in left prefrontal cortex and left thalamus of first-episode patients with early onset schizophrenia: A magnetic resonance spectroscopy study.

Early onset schizophrenia (EOS) is often associated with poorer outcomes, including lack of school education, higher risk of mental disability and resistance to treatment. But the knowledge of the neurobiological mechanism of EOS is limited. Here, using proton magnetic resonance spectroscopy, we investigated the possible neurochemical abnormalities in prefrontal cortex (PFC) and thalamus of first-episode drug-naïve patients with EOS, and followed up the effects of atypical antipsychotic treatment for 6 months on neurochemical metabolites and clinical symptoms. We measured the ratios of N-acetylaspartate (NAA), choline (Cho) to creatine (Cr) in 41 adolescents with first episode of EOS and in 28 healthy controls matched for age, gender, and years of education. The EOS patients presented with abnormally low NAA/Cr values in the left PFC and left thalamus with a reduced tendency in the right PFC compared with healthy controls. No significant differences were detected between groups for Cho/Cr in PFC and thalamus in any hemisphere. After atypical antipsychotic treatment for 6 months, the reduced NAA/Cr in the left PFC and left thalamus in EOS patients was elevated to the normal level in healthy controls, without any alteration in Cho/Cr. We also found that there was no significant correlation between the neurochemical metabolite ratios in the PFC and thalamus in patients with EOS, and clinical characteristics. Our results suggest that there was neurochemical metabolite abnormalities in PFC and thalamus in EOS patients, atypical antipsychotic treatment can effectively relieve the symptoms and restore the reduced NAA in PFC and thalamus.