Original Research ARTICLE
Gyrification Connectomes in Unmedicated Patients with Schizophrenia and Following a Short Course of Antipsychotic Drug Treatment
- 1Department of Psychiatry, University of Alabama at Birmingham, United States
Schizophrenia (SZ) is a disease characterized by brain dysconnectivity and abnormal brain development. The study of cortical gyrification in schizophrenia may capture underlying alterations reflective of neurodevelopmental abnormalities better than other imaging modalities. Graph-based connectomic approaches have been previously used in schizophrenia to study structural and functional brain covariance using a diversity of techniques. The goal of the present study was to evaluate morphological covariance using a measure of local gyrification index in patients with schizophrenia. The aims of this study were twofold: (1) Evaluate, in unmedicated SZ, the structural covariance of local gyrification index using graph theory measures of integration and segregation, and (2) investigate the effect of a short antipsychotic drug (APD) treatment on these measures.
Using a longitudinal prospective design, structural scans were obtained prior to treatment in 34 unmedicated patients with SZ and after 6 weeks of treatment with risperidone. To control for the effect of time, 23 matched healthy controls (HC) were also scanned twice, 6 weeks apart. The cortical surface of each structural image was reconstructed and local gyrification index values were computed using FreeSurfer. Local gyrification index values where then parcellated into atlas based regions and entered into a 68 × 68 correlation matrix to construct local gyrification index connectomes for each group at each time point.
Longitudinal comparisons showed significant group by time interactions for measures of segregation (clustering, local efficiency) and modularity, but not for measures of integration (path length, global efficiency). Post hoc tests showed increased clustering, local efficiency, and modularity connectomes in unmedicated patients with SZ compared to HC. After 6 weeks of treatment, there were no significant differences between the groups on these measures
Abnormal cortical topography is detected in schizophrenia, likely indexing neurodevelopmental trajectory deviations. In addition, cortical topography is modified by short term APD treatment reflective of decreases in hyper-specialization in network connectivity. We speculate that changes in the structural organization of the brain is achieved through the trophic effects that APDs have on brain tissue, thus promoting better brain connections and, possibly, a therapeutic effect.
Keywords: Schizophrenia, antipsychotic medication, graph analysis, Gyrification index, prospective design
Received: 17 Oct 2018;
Accepted: 03 Dec 2018.
Edited by:Lena K. Palaniyappan, University of Western Ontario, Canada
Reviewed by:Maria R. Dauvermann, National University of Ireland Galway, Ireland
Tsutomu Takahashi, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Japan
Copyright: © 2018 Nelson, White, Kraguljac and Lahti. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: MD. Adrienne C. Lahti, University of Alabama at Birmingham, Department of Psychiatry, Birmingham, United States, firstname.lastname@example.org