Abnormal cerebellar volume in somatic vs. non-somatic delusional disorders

Abstract

Background: There is abundant evidence for cerebellar involvement in schizophrenia, where the cerebellum has been suggested to contribute to cognitive, affective and motor dysfunction. More recently, specific cerebellar regions have also been associated with psychotic symptoms, particularly with auditory verbal hallucinations. In contrast, little is known about cerebellar contributions to delusions, and even less is known about whether cerebellar involvement differs by delusional content. Methods: Using structural magnetic resonance imaging at 1.0 T together with cerebellum-optimized segmentation techniques, we investigated gray matter volume (GMV) in 14 patients with somatic-type delusional disorder (S-DD), 18 patients with non-somatic delusional disorder (NS-DD) and 18 patients with schizophrenia (SZ) with persistent non-somatic delusions. A total of 32 healthy controls (HC) were included. Between-group comparisons were adjusted for age, gender, chlorpromazine equivalents and illness duration. Results: Compared to HC, S-DD patients showed decreased GMV in left lobule VIIIa. In addition, S-DD patients showed decreased GMV in lobule V and increased GMV in bilateral lobule VIIa/crus II compared to NS-DD. Patients with SZ showed increased GMV in right lobule VI and VIIa/crus I compared to HC. Significant differences between HC and NS-DD were not found. Conclusions: The data support the notion of cerebellar dysfunction in psychotic disorders. Distinct cerebellar deficits, predominantly linked to sensorimotor processing, may be detected in delusional disorders presenting with predominantly somatic content.

Abnormal Cerebellar Volume in Patients with Remitted Major Depression with Persistent Cognitive Deficits

“…To investigate between-group differences, voxel-wise t tests were calculated. As in previous studies [ 35 , 36 ], given a strong a priori hypothesis, we chose a significance threshold of p < 0.005 (uncorrected at the voxel level) to assess between-group differences. Based on random field theory [ 37 ], an empirically determined extent threshold according to the expected number of voxels per cluster within the respective contrast was applied.…”

Delusional Disorder in Old Age: A Hypothesis-Driven Review of Recent Work Focusing on Epidemiology, Clinical Aspects, and Outcomes

“…The third hypothesis was that poor response to treatment in DD in old age would be associated with brain changes and/or cognitive defects. Several of the studies we reviewed point to the presence of neurobiological correlates of delusions (cerebellar abnormalities [20], alterations in gray and white matter, lacunar infarctions and ischemic brain lesions in DD [19,22,29,30]. Our literature search suggests, but does not prove, that brain lesions can impair the response to psychotropic medications in the elderly age group [20].…”

“…Krämer et al [20] carried out a brain-imaging study in 14 patients with DD somatictype, 18 patients with nonsomatic DD, 18 patients with schizophrenia (SZ) and 32 healthy controls. Cerebellum-optimized segmentation images were obtained by MRI.…”

Significant Structural Alterations and Functional Connectivity Alterations of Cerebellar Gray Matter in Patients With Somatic Symptom Disorder

“…Higher GMV in the bilateral lobule VIIa/crus II has been detected in patients with somatic-type delusional disorder than in those with non-somatic delusional disorder. Patients with schizophrenia also showed increased GMV in VIIa/crus I compared with HC ( Krämer et al, 2020 ). Task-based fMRI confirmed that crus I is activated by executive functions such as working memory, planning, organizing, and strategy formation.…”

“…Finally, sex differences in GMV may account for the inconsistency; the proportion of men among SD patients in the study is only 4/25. The SUIT toolbox offers a high-resolution, spatially unbiased template of the human cerebellum, enabling more accurate intersubject alignment than whole-brain methods (Krämer et al, 2020). In some cases, SUIT is more sensitive to cerebellar changes than conventional whole-brain VBM (Diedrichsen, 2006;Kühn et al, 2012).…”