White Matter Microstructural Differences between Hallucinating and Non-Hallucinating Schizophrenia Spectrum Patients.

Justyna Beresniewicz,Else-Marie Løberg,Erik Johnsen,Rune Andreas Kroken,Kenneth Hugdahl,Alexander R Craven,Renate Grüner

doi:10.3390/diagnostics11010139

Justyna Beresniewicz, Else-Marie Løberg + Show 5 more

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https://doi.org/10.3390/diagnostics11010139

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Abstract

The relation between auditory verbal hallucinations (AVH) and white matter has been studied, but results are still inconsistent. This inconsistency may be related to having only a single time-point of AVH assessment in many studies, not capturing that AVH severity fluctuates over time. In the current study, AVH fluctuations were captured by utilizing a longitudinal design and using repeated (Positive and Negative Symptoms Scale) PANSS questionnaire interviews over a 12 month period. We used a Magnetic Resonance Diffusion Tensor Imaging (MR DTI) sequence and tract-based spatial statistics (TBSS) to explore white matter differences between two subtypes of schizophrenia patients; 44 hallucinating (AVH+) and 13 non-hallucinating (AVH-), compared to 13 AVH- matched controls and 44 AVH+ matched controls. Additionally, we tested for hemispheric fractional anisotropy (FA) asymmetry between the groups. Significant widespread FA-value reduction was found in the AVH+ group in comparison to the AVH- group. Although not significant, the extracted FA-values for the control group were in between the two patient groups, for all clusters. We also found a significant difference in FA-asymmetry between the AVH+ and AVH- groups in two clusters, with significantly higher leftward asymmetry in the AVH- group. The current findings suggest a possible qualitative difference in white matter integrity between AVH+ and AVH- patients. Strengths and limitations of the study are discussed.

Highlights

It has been suggested that auditory verbal hallucinations (AVH) may involve alterations in structural and functional connectivity of frontal and temporoparietal language-related brain areas [6,7,8] as well as altered internode connectivity within large-scale networks such as the default mode network (DMN) [9,10]
By using diffusion tensor imagining (DTI) to explore microstructural changes in vivo, a substantial number of studies have reported on a correlation between white matter integrity and schizophrenia [11,12,13,14,15,16]
The most consistent finding was the alteration of hemispheric language pathways in AVH+ patients, which has been reported in previous studies, the nature and direction of this relation have often differed [6,15,16,19]

Summary

Introduction

A majority of patients with schizophrenia experience auditory verbal hallucinations (AVH) [5]. The neural underpinnings of the symptoms the patient experiences have been extensively investigated, yet remain unclear. It has been suggested that AVH may involve alterations in structural and functional connectivity of 4.0/). By using diffusion tensor imagining (DTI) to explore microstructural changes in vivo, a substantial number of studies have reported on a correlation between white matter integrity and schizophrenia [11,12,13,14,15,16]. The association between AVH, as a key symptom in schizophrenia, and white matter integrity is still not fully understood, and findings are often contradictory.

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