Cerebellar parcellation in schizophrenia and bipolar disorder.

OBJECTIVE: The cerebellum is involved in cognitive processing and emotion control. Cerebellar alterations could explain symptoms of schizophrenia spectrum disorder (SZ) and bipolar disorder (BD). In addition, literature suggests that lithium might influence cerebellar anatomy. Our aim was to study cerebellar anatomy in SZ and BD, and investigate the effect of lithium. METHODS: Participants from 7 centers worldwide underwent a 3T MRI. We included 182 patients with SZ, 144 patients with BD, and 322 controls. We automatically segmented the cerebellum using the CERES pipeline. All outputs were visually inspected. RESULTS: Patients with SZ showed a smaller global cerebellar gray matter volume compared to controls, with most of the changes located to the cognitive part of the cerebellum (Crus II and lobule VIIb). This decrease was present in the subgroup of patients with recent-onset SZ. We did not find any alterations in the cerebellum in patients with BD. However, patients medicated with lithium had a larger size of the anterior cerebellum, compared to patients not treated with lithium. CONCLUSION: Our multicenter study supports a distinct pattern of cerebellar alterations in SZ and BD.

Social cognition in autism is associated with the neurodevelopment of the posterior superior temporal sulcus.

OBJECTIVE: The posterior superior temporal sulcus (pSTS) plays a critical role in the 'social brain'. Its neurodevelopment and relationship with the social impairment in autism spectrum disorders (ASD) are not well understood. We explored the relationship between social cognition and the neurodevelopment of the pSTS in ASD. METHOD: We included 44 adults with high-functioning ASD and 36 controls. We assessed their performances on the 'Reading the mind in the eyes' test (for 34 of 44 subjects with ASD and 30 of 36 controls), their fixation time on the eyes with eye tracking (for 35 of 44 subjects with ASD and 30 of 36 controls) and the morphology of the caudal branches of the pSTS (length and depth), markers of the neurodevelopment, with structural MRI. RESULTS: The right anterior caudal ramus of the pSTS was significantly longer in patients with ASD compared with controls (52.6 mm vs. 38.3 mm; P = 1.4 × 10-3 ; Cohen's d = 0.76). Its length negatively correlated with fixation time on the eyes (P = 0.03) in the ASD group and with the 'Reading the mind in the eyes' test scores in both groups (P = 0.03). CONCLUSION: Our findings suggest that the neurodevelopment of the pSTS is related to the ASD social impairments.

Similar white matter but opposite grey matter changes in schizophrenia and high-functioning autism.

OBJECTIVE: High-functioning autism (HFA) and schizophrenia (SZ) are two of the main neurodevelopmental disorders, sharing several clinical dimensions and risk factors. Their exact relationship is poorly understood, and few studies have directly compared both disorders. Our aim was thus to directly compare neuroanatomy of HFA and SZ using a multimodal MRI design. METHODS: We scanned 79 male adult subjects with 3T MRI (23 with HFA, 24 with SZ and 32 healthy controls, with similar non-verbal IQ). We compared them using both diffusion-based whole-brain tractography and T1 voxel-based morphometry. RESULTS: HFA and SZ groups exhibited similar white matter alterations in the left fronto-occipital inferior fasciculus with a decrease in generalized fractional anisotropy compared with controls. In grey matter, the HFA group demonstrated bilateral prefrontal and anterior cingulate increases in contrast with prefrontal and left temporal reductions in SZ. CONCLUSION: HFA and SZ may share common white matter deficits in long-range connections involved in social functions, but opposite grey matter abnormalities in frontal regions that subserve complex cognitive functions. Our results are consistent with the fronto-occipital underconnectivity theory of HFA and the altered connectivity hypothesis of SZ and suggest the existence of both associated and diametrical liabilities to these two conditions.

Cerebellar volume in schizophrenia and bipolar I disorder with and without psychotic features.

OBJECTIVE: There is growing evidence that cerebellum plays a crucial role in cognition and emotional regulation. Cerebellum is likely to be involved in the physiopathology of both bipolar disorder and schizophrenia. The objective of our study was to compare cerebellar size between patients with bipolar disorder, patients with schizophrenia, and healthy controls in a multicenter sample. In addition, we studied the influence of psychotic features on cerebellar size in patients with bipolar disorder. METHOD: One hundred and fifteen patients with bipolar I disorder, 32 patients with schizophrenia, and 52 healthy controls underwent 3 Tesla MRI. Automated segmentation of cerebellum was performed using FreeSurfer software. Volumes of cerebellar cortex and white matter were extracted. Analyses of covariance were conducted, and age, sex, and intracranial volume were considered as covariates. RESULTS: Bilateral cerebellar cortical volumes were smaller in patients with schizophrenia compared with patients with bipolar I disorder and healthy controls. We found no significant difference of cerebellar volume between bipolar patients with and without psychotic features. No change was evidenced in white matter. CONCLUSION: Our results suggest that reduction in cerebellar cortical volume is specific to schizophrenia. Cerebellar dysfunction in bipolar disorder, if present, appears to be more subtle than a reduction in cerebellar volume.

Cytomegalovirus seropositivity and serointensity are associated with hippocampal volume and verbal memory in schizophrenia and bipolar disorder.

INTRODUCTION: Cytomegalovirus (CMV) is a member of the herpesviridae family that has a limbic and temporal gray matter tropism. It is usually latent in humans but has been associated with schizophrenia, bipolar disorder and cognitive deficits in some populations. Hippocampal decreased volume and dysfunction play a critical role in these cognitive deficits. We hypothesized that CMV seropositivity and serointensity would be associated with hippocampal volume and cognitive functioning in patients with schizophrenia or bipolar disorder. METHODS: 102 healthy controls, 118 patients with bipolar disorder and 69 patients with schizophrenia performed the California Verbal Learning Test (CVLT) and had blood samples drawn to assess CMV IgG levels. A subgroup of 52 healthy controls, 31 patients with bipolar disorder and 27 patients with schizophrenia underwent T1 MRI for hippocampal volumetry. We analyzed the association between CMV serointensity and seropositivity with hippocampal volume. We also explored the correlation between CMV serointensity and seropositivity and CVLT scores. RESULTS: In both patient groups but not in controls, higher CMV serointensity was significantly associated with smaller right hippocampal volume. Further, in the group of patients with schizophrenia but not bipolar disorder, CMV serointensity was negatively correlated with CVLT scores. CONCLUSION: CMV IgG titers are associated with decreased hippocampal volume and poorer episodic verbal memory in patients with schizophrenia or bipolar disorder. The mechanism of this association warrants further exploration.