Association between cortical volume and gray-white matter contrast with second generation antipsychotic medication exposure in first episode male schizophrenia patients

Correlation of Immune-Inflammatory Response System (IRS)/Compensatory Immune-Regulatory Reflex System (CIRS) with White Matter Integrity in First-Episode Patients with Schizophrenia

Several studies have reported compromised white matter integrity, and that some inflammatory mediators may underlie this functional dysconnectivity in the brain of patients with schizophrenia. The immune-inflammatory response system and compensatory immune-regulatory reflex system (IRS/CIRS) are novel biomarkers for exploring the role of immune imbalance in the pathophysiological mechanism of schizophrenia. This study aimed to explore the little-known area regarding the composite score of peripheral cytokines, the IRS/CIRS, and its correlation with white matter integrity and the specific microstructures most affected in schizophrenia. First-episode patients with schizophrenia (FEPS, n = 94) and age- and sex-matched healthy controls (HCs, n = 50) were enrolled in this study. Plasma cytokine levels were measured using enzyme-linked immunosorbent assay (ELISA), and psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS). The whole brain white matter integrity was measured by fractional anisotropy (FA) from diffusion tensor imaging (DTI) using a 3-T Prisma MRI scanner. The IRS/CIRS in FEPS was significantly higher than that in HCs (p = 1.5 × 10-5) and Cohen's d effect size was d = 0.74. FEPS had a significantly lower whole-brain white matter average FA (p = 0.032), which was negatively associated with IRS/CIRS (p = 0.029, adjusting for age, sex, years of education, BMI, and total intracranial volume), but not in the HCs (p > 0.05). Among the white matter microstructures, only the cortico-spinal tract was significantly correlated with IRS/CIRS in FEPS (r =  - 0.543, p = 0.0009). Therefore, elevated IRS/CIRS may affect the white matter in FEPS.

The relationship between gray/white matter contrast and cognitive performance in first-episode schizophrenia

Previous postmortem brain studies have revealed disturbed myelination in the intracortical regions in patients with schizophrenia, possibly reflecting anomalous brain maturational processes. However, it currently remains unclear whether this anomalous myelination is already present in early illness stages and/or progresses during the course of the illness. In this magnetic resonance imaging study, we examined gray/white matter contrast (GWC) as a potential marker of intracortical myelination in 63 first-episode schizophrenia (FESz) patients and 77 healthy controls (HC). Furthermore, we investigated the relationships between GWC findings and clinical/cognitive variables in FESz patients. GWC in the bilateral temporal, parietal, occipital, and insular regions was significantly higher in FESz patients than in HC, which was partly associated with the durations of illness and medication, the onset age, and lower executive and verbal learning performances. Because higher GWC implicates lower myelin in the deeper layers of the cortex, these results suggest that schizophrenia patients have less intracortical myelin at the time of their first psychotic episode, which underlies lower cognitive performance in early illness stages.

Cortical thickness, gray-white matter contrast, and intracortical myelin in first-episode schizophrenia patients treated with long-acting paliperidone palmitate versus oral antipsychotics

This longitudinal study evaluated the cortical thickness, gray-to-white matter contrast (GWC), and frontal lobe intracortical myelin (ICM) volume in first-episode schizophrenia (FES) patients treated with oral antipsychotics (OAP) versus a long-acting injectable antipsychotic, paliperidone palmitate (PP). 2D proton density and inversion recovery images, and 3D T1-weighted MPRAGE images were acquired at 3T from 68 FES patients in a randomized clinical trial with PP vs OAP. At baseline, no differences in GWC and ICM were observed between FES patients and HCs, but the thickness of the left precuneus, the right transverse temporal gyrus, and the bilateral superior temporal gyri was found to be thinner in FES patients relative to HCs. Following 9 months of antipsychotics, OAP treatment, compared to PP treatment, resulted in a more widespread cortical thickness reduction including the right lateral occipital and orbitofrontal gyri. No significant ICM and GWC changes were observed in the PP group, whereas OAP treatment led to a significant ICM volume decrease and GWC increase. A negative correlation was found between ICM changes and GWC changes within multiple frontal regions after 9 months of OAP treatment. These preliminary findings suggest that PP treatment might aid preservation of brain morphology.

Prospective, randomized, multicenter clinical trial evaluating longitudinal changes in brain function and microstructure in first-episode schizophrenia patients treated with long-acting injectable paliperidone palmitate versus oral antipsychotics

Widespread anatomical alterations and abnormal functional connectivity have shown strong association with symptom severity in first-episode schizophrenia (FES) patients. Second-generation antipsychotic treatment might slow disease progression and possibly modify the cerebral plasticity in FES patients. However, whether a long-acting injectable antipsychotic (paliperidone palmitate [PP]), available in monthly and every-3-months formulations, is more effective than oral antipsychotics (OAP) in improving cerebral organization has been unclear. Therefore, in the current longitudinal study, we evaluated the differences in functional and microstructural changes of 68 FES patients in a randomized clinical trial of PP vs OAP. When compared to OAP treatment, PP treatment was more effective in decreasing abnormally high fronto-temporal and thalamo-temporal connectivity, as well as increasing fronto-sensorimotor and thalamo-insular connectivity. Consistent with previous studies, multiple white matter pathways showed larger changes in fractional anisotropy (FA) and mean diffusivity (MD) in response to PP compared with OAP treatment. These findings suggest that PP treatment might reduce regional abnormalities and improve cerebral connectivity networks compared with OAP treatment, and identified changes that may serve as reliable imaging biomarkers associated with medication treatment efficacy.

Effect of treatment with paliperidone palmitate versus oral antipsychotics on frontal lobe intracortical myelin volume in participants with recent-onset schizophrenia: Magnetic resonance imaging results from the DREaM study

OBJECTIVE

We investigated changes in brain intracortical myelin (ICM) volume in the frontal lobe after 9 months of treatment with paliperidone palmitate (PP) compared with 9 months of treatment with oral antipsychotics (OAP) in participants with recent-onset schizophrenia or schizophreniform disorder from the Disease Recovery Evaluation and Modification (DREaM) study, a randomized, open-label, delayed-start trial.

METHODS

DREaM included 3 phases: Part I, a 2-month oral run-in; Part II, a 9-month disease progression phase (PP or OAP); and Part III, 9 months of additional treatment (participants receiving PP continued PP [PP/PP] and participants receiving OAP were rerandomized to receive either PP [OAP/PP] or OAP [OAP/OAP]). In Part II, magnetic resonance imaging (MRI) and functional and symptomatic assessment was performed at baseline, day 92, and day 260. ICM volume as a fraction of the entire brain volume was quantified by subtraction of a proton density image from an inversion recovery image. Within-treatment-group changes from baseline were assessed by paired t-tests. Analysis of covariance was used to analyze ICM volume changes between treatment groups, adjusting for country.

RESULTS

The MRI analysis sample size included 71 DREaM participants (PP, 23; OAP, 48) and 64 healthy controls. At baseline, mean adjusted ICM fraction values did not differ between groups (PP, 0.057; OAP, 0.058, p = 0.79). By day 92, the adjusted ICM fraction in the OAP group had decreased significantly (change from baseline, -0.002; p = 0.001), whereas the adjusted ICM fraction remained unchanged from baseline in the PP group (0.000; p = 0.80). At day 260, the change from baseline in adjusted ICM fraction was -0.004 (p = 0.004) in the OAP group and -0.001 (p = 0.728) in the PP group. The difference between treatment groups did not reach statistical significance (p = 0.147).

CONCLUSIONS

In participants with recent-onset schizophrenia or schizophreniform disorder, frontal ICM volume was preserved at baseline levels in those treated with PP over 9 months. However, a decrease of frontal ICM volume was observed among participants treated with OAPs.

TRIAL REGISTRATION

clinicaltrials.gov identifier NCT02431702.

Systematic Review of Functional MRI Applications for Psychiatric Disease Subtyping

Background: Psychiatric disorders have been historically classified using symptom information alone. Recently, there has been a dramatic increase in research interest not only in identifying the mechanisms underlying defined pathologies but also in redefining their etiology. This is particularly relevant for the field of personalized medicine, which searches for data-driven approaches to improve diagnosis, prognosis, and treatment selection for individual patients. Methods: This review aims to provide a high-level overview of the rapidly growing field of functional magnetic resonance imaging (fMRI) from the perspective of unsupervised machine learning applications for disease subtyping. Following the PRISMA guidelines for protocol reproducibility, we searched the PubMed database for articles describing functional MRI applications used to obtain, interpret, or validate psychiatric disease subtypes. We also employed the active learning framework ASReview to prioritize publications in a machine learning-guided way. Results: From the 20 studies that met the inclusion criteria, five used functional MRI data to interpret symptom-derived disease clusters, four used it to interpret clusters derived from biomarker data other than fMRI itself, and 11 applied clustering techniques involving fMRI directly. Major depression disorder and schizophrenia were the two most frequently studied pathologies (35% and 30% of the retrieved studies, respectively), followed by ADHD (15%), psychosis as a whole (10%), autism disorder (5%), and the consequences of early exposure to violence (5%). Conclusions: The increased interest in personalized medicine and data-driven disease subtyping also extends to psychiatric disorders. However, to date, this subfield is at an incipient exploratory stage, and all retrieved studies were mostly proofs of principle where further validation and increased sample sizes are craved for. Whereas results for all explored diseases are inconsistent, we believe this reflects the need for concerted, multisite data collection efforts with a strong focus on measuring the generalizability of results. Finally, whereas functional MRI is the best way of measuring brain function available to date, its low signal-to-noise ratio and elevated monetary cost make it a poor clinical alternative. Even with technology progressing and costs decreasing, this might incentivize the search for more accessible, clinically ready functional proxies in the future.