Working Memory Function in Recent-Onset Schizophrenia Patients Associated With White Matter Microstructure: Connectometry Approach Publisher



Dolatshahi M¹ ; Rahmani F² ; Shadmehr MH³ ; Peoppl T⁴ ; Shojaie A¹ ; Noorizadeh F¹ ; Aarabi MH¹ ; Mohammadi Jooyandeh S⁴ Show Affiliations
Source: Mathematics and Visualization Published:2017

Abstract

Schizophrenia is a kind of psychosis accompanied by cognitive deficits. In addition, white matter abnormalities are observed in various brain regions and tracts in the disease. Association of some tracts like superior longitudinal fasciculus (SLF), inferior longitudinal fasciculus (ILF), inferior fronto-occipital fasciculus (IFOF) with working memory function have been observed using diffusion MRI analysis methods such as tract-based spatial statistics (TBSS). Thus, we applied connectometry, not suffering from some limitations of tract specific analysis, in a group of 29 patients and 32 healthy controls to investigate association of working memory performance (as measured by letter-number sequencing test) with white matter integrity in recent-onset schizophrenic patients, who are less affected by antipsychotic medications. Connectometry is a recently introduced approach utilized to associate local connectomes with a study variable along the fiber pathways themselves instead of finding the difference in the whole fiber pathways. This study showed that lesser integrity of some fiber tracts like the arcuate fasciculus, the inferior longitudinal fasciculus, the body of corpus callosum and also some fibers of corticospinal tract, IFOF, and cingulum bundle associated with working memory deficits in schizophrenic patients while healthy controls did not show any correlation unless the percentage threshold was increased up to 45%. These results are consistent with previous ones to a large extent but we also found some fiber tracts other than previous studies like the body of corpus callosum and some fibers of corticospinal tract. On the whole, Our study further supports disconnectivity hypothesis in schizophrenia, playing a major role in cognitive dysfunction. © Springer International Publishing AG 2017.