Psychopathology and Integrity of the Superior Longitudinal Fasciculus in Deficit and Nondeficit Schizophrenia

Abstract

The superior longitudinal fasciculus (SLF) is a white matter bundle that connects the frontal areas with the parietal areas. As part of the visuospatial attentional network, it may be involved in the development of schizophrenia. Deficit syndrome (DS) is characterized by primary and enduring negative symptoms. The present study assessed SLF integrity in DS and nondeficit schizophrenia (NDS) patients and examined possible relationships between it and psychopathology. Twenty-six DS patients, 42 NDS patients, and 36 healthy controls (HC) underwent psychiatric evaluation and diffusion tensor imaging (DTI). After post-processing, fractional anisotropy (FA) values within the SLF were analyzed. Psychopathology was assessed with the Positive and Negative Syndrome Scale, Brief Negative Symptom Scale, and Self-evaluation of Negative Symptoms. The PANSS proxy for the deficit syndrome was used to diagnose DS. NDS patients had lower FA values than HC. DS patients had greater negative symptoms than NDS patients. After differentiating clinical groups and HC, we found no significant correlations between DTI measures and psychopathological dimensions. These results suggest that changes in SLF integrity are related to schizophrenia, and frontoparietal dysconnection plays a role in its etiopathogenesis. We confirmed that DS patients have greater negative psychopathology than NDS patients. These results are preliminary; further studies are needed.

Differences in inflammatory marker profiles and cognitive functioning between deficit and nondeficit schizophrenia

“…The proportion of DS patients reported in our study (36.17%) was higher than that found in some previous studies that used the Schedule for Deficit Syndrome (SDS) for categorizing deficit syndrome ( 25 , 26 ), but was similar to some others that used the PDS scale ( 4 , 27 ). Interestingly, a recent meta-analysis summarized the existing research with the SDS scale and calculated the pooled proportion of the DS subgroup was 32.64% ( 28 ).…”

“…Clinically, schizophrenia is a heterogeneous disease that manifests a variety of symptoms, which poses challenges to understanding its neurobiological mechanisms ( 47 ). In turn, classifying different subtypes and subpopulations of the disorder was regarded as a productive approach to overcoming this heterogeneity ( 27 ). An increasing amount of evidence has shown that DS is a homogeneous subtype of schizophrenia, with unique pathophysiological and psychological features.…”

Tract-based analyses of white matter in schizophrenia, bipolar disorder, aging, and dementia using high spatial and directional resolution diffusion imaging: a pilot study

“…The SLF is the largest associative fiber bundle system in the brain, and connects the frontal, temporal, and parietal lobes within the same hemisphere ( 74 , 75 ). The main functions supported by the regions connected by the SLF are visual and spatial cognition, attention processes, control of motor processes and executive functions, and language functions ( 76 ). SLF-I represents the dorsal division, connecting the superior parietal and superior frontal lobes, and appears to be involved with regulating motor behavior.…”

“…The SLF-III is the most ventral, extending from the supramarginal gyrus, anterior to the angular gyrus, to the ventral premotor and prefrontal areas. Frontoparietal dysconnectivity has been attributed to SCZ etiopathogenesis ( 76 ), and impaired SLF has been found in SCZ in several studies ( 7 , 8 , 77 – 79 ) and associated with psychotic symptom severity ( 79 , 80 ). Our results are consistent with these findings and suggest that decreased integrity of SLF tracts may indicate a more advanced symptom profile.…”

Using support vector machine to explore the difference of function connection between deficit and non-deficit schizophrenia based on gray matter volume

“…Magnetic resonance imaging (MRI) is widely used in a variety of mental illness and nervous system disease research, and provided early promise for the discovery of the neuroanatomical differences between the two subtypes of schizophrenia ( Wang et al, 2015 ; Lei et al, 2019 ). Some studies found excessive DS-specific brain structural changes in gray matter volume (GMV), white matter volume, CSF volume, and cortical structure; including frontal, parietal, and temporal regions ( Fischer et al, 2012 ; Podwalski et al, 2022 ). However, previous functional neuroimaging studies about the functional connectivity differences between these two subgroups of schizophrenia based on ROI from GMV are scarce.…”