Ventral striatum gray matter density reduction in patients with schizophrenia and psychotic emotional dysregulation

Abstract

IntroductionSubstantial heterogeneity remains across studies investigating changes in gray matter in schizophrenia. Differences in methodology, heterogeneous symptom patterns and symptom trajectories may contribute to inconsistent findings. To address this problem, we recently proposed to group patients by symptom dimensions, which map on the language, the limbic and the motor systems. The aim of the present study was to investigate whether patients with prevalent symptoms of emotional dysregulation would show structural neuronal abnormalities in the limbic system.Method43 right-handed medicated patients with schizophrenia were assessed with the Bern Psychopathology Scale (BPS). The patients and a control group of 34 healthy individuals underwent structural imaging at a 3T MRI scanner. Whole brain voxel-based morphometry (VBM) was compared between patient subgroups with different severity of emotional dysregulation. Group comparisons (comparison between patients with severe emotional dysregulation, patients with mild emotional dysregulation, patients with no emotional dysregulation and healthy controls) were performed using a one way ANOVA and ANCOVA respectively.ResultsPatients with severe emotional dysregulation had significantly decreased gray matter density in a large cluster including the right ventral striatum and the head of the caudate compared to patients without emotional dysregulation. Comparing patients with severe emotional dysregulation and healthy controls, several clusters of significant decreased GM density were detected in patients, including the right ventral striatum, head of the caudate, left hippocampus, bilateral thalamus, dorsolateral prefrontal and orbitofrontal cortex. The significant effect in the ventral striatum was lost when patients with and without emotional dysregulation were pooled and compared with controls.DiscussionDecreased gray matter density in a large cluster including the right ventral striatum was associated with severe symptoms of emotional dysregulation in patients with schizophrenia. The ventral striatum is an important part of the limbic system, and was indicated to be involved in the generation of incentive salience and psychotic symptoms. Only patients with severe emotional dysregulation had decreased gray matter in several brain structures associated with emotion and reward processing compared to healthy controls. The results support the hypothesis that grouping patients according to specific clinical symptoms matched to the limbic system allows identifying patient subgroups with structural abnormalities in the limbic network.

Systems Neuroscience of Psychosis: Mapping Schizophrenia Symptoms onto Brain Systems

“…Indirect signs of limbic dysfunction are delusions of abnormal threats or powers. Consistently, we have demonstrated that gray matter abnormalities in a key region of the limbic system, i.e., the ventral striatum, were specifically related to emotional dysregulation in schizophrenia, but at the same time unrelated to schizophrenia in general [59]. Furthermore, the probability of a structural connection between the ventral striatum and the amygdala was increased as a function of paranoid symptoms [97].…”

“…Good internal consistency and external validity of the BPS have been shown in several studies [59, 65-74]. …”

Amygdala and dlPFC abnormalities, with aberrant connectivity and habituation in response to emotional stimuli in females with BPD

“…Reduced ventral striatal grey matter volume has been linked to emotional dysregulation central to BPD. In a study of schizophrenic patients, the largest volume difference in a voxel-based-morphometry study was found in the left ventral striatum of patients only with severe emotional dysregulation and not in patients without emotional dysregulation 64 . However, underlying mechanisms at the cellular level driving observed changes remain unclear from voxel-based morphometry studies 65,66 .…”

Possible neurophysiological mechanisms for mild-exercise-enhanced executive function: An fNIRS neuroimaging study

“…The PFC can be divided into three sub-regions: dorsolateral (8, 9 and 46), ventrolateral (44,45, and lateral 47) and frontopolar (10), based on the Brodmann areas, and each region is interconnected with various brain areas processing external information, including sensory systems, cortical and subcortical motor systems, the brain stem, as well as internal information from limbic and midbrain sites involved in affect, memory, and reward 19,20) . Specifically, dorsal regions of the PFC are highly interconnected with brain regions such as the anterior cingulate cortex (ACC) involved in top-down cognitive control 21) , while ventral regions of the PFC interconnect with limbic systems involved with emotion 22,23) . In addition, the PFC also receives neuronal inputs from the brainstem arousal systems 24) .…”