Cingulum bundle integrity in schizophrenia with auditory verbal hallucinations: A diffusion tensor imaging tractographic study

Background & objectives: Cingulum bundle (CB) is frequently implicated in schizophrenia; however, its role in specific symptoms of schizophrenia such as auditory verbal hallucinations (AVHs) is less explored. Few studies have reported association between reduced integrity of CB and severity of AVH. Using a symptom-based approach, this diffusion tensor imaging (DTI) tractographic study was aimed to assess and compare the integrity of CB in schizophrenia with AVH, schizophrenia without AVH and healthy controls. Methods: A total of 92 right-handed adult individuals (aged 18-50 yr) were recruited across three study groups. Those with Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) diagnosis of schizophrenia with AVH (group I; n=30) were compared to those with DSM-5 schizophrenia without lifetime AVH (group II; n=32) and healthy controls (group III; n=30; screened using Mini International Neuropsychiatric Interview version-7.0.0. and negative family history). Clinical assessments (groups I and II) included scale for assessment of positive symptoms, scale for assessment of negative symptoms, clinical global impression-schizophrenia and psychotic symptom rating scale. All participants underwent DTI, and quantitative tract-based measurements of fractional anisotropy (FA) were obtained for images using DTI studio version-3.0. Results: All groups were comparable for age, gender, education and severity of illness. Group I had significantly lower FA values in the cingulate gyrus (CG) part of the left CB compared to groups II and III. No significant difference was found between groups II and III. Interpretation & conclusions: The findings of this study suggest that the disruption in the left CB appears to be specific for AVH-positive schizophrenia. The finding is, however, preliminary subject to replication in future studies. Further investigations are needed to understand its relevance in the context of AVH-positive schizophrenia.

Changes of microstructure of white matter and clinical high risk for psychosis / 中华行为医学与脑科学杂志

The research on clinical high-risk for psychosis is a hotspot in recent years, which is helpful to the early identification and early intervention of psychosis. White matter fibers are the important structural basis of complex information transmission function among brain regions. The existing literatures show that there are abnormal white matter microstructures in individuals at clinical high-risk for psychosis, which is related to their clinical symptoms and social function. Diffusion tensor imaging is the only non-invasive technique to study the microstructure of brain white matter. This paper reviews the existing evidences of microstructural abnormalities of white matter at clinical high-risk for psychosis by diffusion tensor imaging, in order to comprehensively analyze the potential neurobiomarkers in the early stage of the disease and the pathological evolution characteristics in the development of the disease.

Impact of Metabolic Syndrome on the White Matter Integrity in Alzheimer's Disease Patients : Tract-Based Spatial Statistics Study under 3-Tesla MRI

OBJECTIVE: The aim of this study is to determine whether there is any difference in white matter (WM) integrity between Alzheimer's disease (AD) with metabolic syndrome (MetS) and without MetS. METHODS: Altogether, 30 subjects were finally recruited from the Memory Impairment Clinics of Pusan National University Hospital in Korea. All subjects (AD with MetS : n=15, matched AD without MetS for age, gender and year of education : n=15) were underwent 3-tesla magnetic resonance imaging scans of diffusion tensor imaging. RESULTS: The mean fractional anisotropy of the AD with MetS was lower (p<0.05) in right posterior corona radiate, right corticospinal tract and right superior longitudinal fasciculus than that of the AD without MetS. CONCLUSION: Our findings suggest that WM integrity damage.

Effects of the Combination Herbal Extract on Working Memory and White Matter Integrity in Healthy Individuals with Subjective Memory Complaints : A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

OBJECTIVES: The combination extract of four kinds of herbs, Gastrodia elata, Liriope platyphylla, Dimocarpus longan, and Salvia miltiorrhiza, has shown to have memory improving effects in mice. The aim of this study was to investigate the efficacy and safety of the herbal mixture for improving working memory as well as microstructural changes in white matter integrity in individuals with subjective memory complaints. METHODS: Seventy-five individuals with subjective memory complaints were assigned to receive either placebo (n = 15) or herbal mixture (low-dose group, n = 30 and high-dose group, n = 30) supplementation in an 8-week, randomized, double-blind, placebo-controlled clinical trial. Changes in working memory performance and fractional anisotropy (FA) values reflecting white matter integrity from baseline to 8-week endpoint were assessed. RESULTS: The herbal mixture group showed an increase in working memory performance compared to the placebo group (p for interaction = 0.001). In addition, the herbal mixture group showed an increase in FA values in the temporo-parietal regions (corrected p < 0.05), which are crucially involved in working memory function and are among the most affected regions in patients with cognitive impairments. CONCLUSIONS: Findings from this study indicate that the herbal mixture may be a promising therapeutic option for individuals with subjective memory complaints.