Regional gray matter volume and structural network strength in somatic vs. non-somatic delusional disorders

Altered temporal lobe connectivity is associated with psychotic symptoms in drug-naïve adolescent patients with first-episode schizophrenia

Research on individuals with a younger onset age of schizophrenia is important for identifying neurobiological processes derived from the interaction of genes and the environment that lead to the manifestation of schizophrenia. Schizophrenia has long been recognized as a disorder of dysconnectivity, but it is largely unknown how brain connectivity changes are associated with psychotic symptoms. Twenty-one adolescent-onset schizophrenia (AOS) patients and 21 matched healthy controls (HCs) were recruited and underwent resting-state functional magnetic resonance imaging. Regional homogeneity (ReHo) was used to investigate local brain connectivity alterations in AOS. Regions with significant ReHo changes in patients were selected as "seeds" for further functional connectivity (FC) analysis and Granger causality analysis (GCA), and associations of the obtained functional brain measures with psychotic symptoms in patients with AOS were examined. Compared with HCs, AOS patients showed significantly increased ReHo in the right middle temporal gyrus (MTG), which was positively correlated with PANSS-positive scores, PSYRATS-delusion scores and auditory hallucination scores. With the MTG as the seed, lower connectivity with the bilateral postcentral gyrus (PCG) and higher connectivity with the right precuneus were observed in patients. The reduced FC between the right MTG and bilateral PCG was significantly and positively correlated with hallucination scores. GCA indicated decreased Granger causality from the right MTG to the left middle frontal gyrus (MFG) and from the right MFG to the right MTG in AOS patients, but such effects did not significantly associate with psychotic symptoms. Abnormalities in the connectivity within the MTG and its connectivity with other networks were identified and were significantly correlated with hallucination and delusion ratings. This region may be a key neural substrate of psychotic symptoms in AOS.

Aberrant Gray Matter Volume and Cortical Surface in Paranoid-Type Delusional Disorder

INTRODUCTION

Delusions are core symptoms of schizophrenia-spectrum and related disorders. Despite their clinical relevance, the neural correlates underlying such phenomena are unclear. Recent research suggests that specific delusional content may be associated with distinct neural substrates.

OBJECTIVE

Here, we used structural magnetic resonance imaging to investigate multiple parameters of brain morphology in patients presenting with paranoid type delusional disorder (pt-DD, n = 14) compared to those of healthy controls (HC, n = 25).

METHODS

Voxel- and surface-based morphometry for structural data was used to investigate gray matter volume (GMV), cortical thickness (CT) and gyrification.

RESULTS

Compared to HC, patients with pt-DD showed reduced GMV in bilateral amygdala and right inferior frontal gyrus. Higher GMV in patients was found in bilateral orbitofrontal and in left superior frontal cortices. Patients also had lower CT in frontal and temporal regions. Abnormal gyrification in patients was evident in frontal and temporal areas, as well as in bilateral insula.

CONCLUSIONS

The data suggest the presence of aberrant GMV in a right prefrontal region associated with belief evaluation, as well as distinct structural abnormalities in areas that essentially subserve processing of fear, anxiety and threat in patients with pt-DD. It is possible that cortical features of distinct evolutionary and genetic origin, i.e. CT and gyrification, contribute differently to the pathogenesis of pt-DD.

Hashimoto’s Encephalopathy Revealed by Hypochondriacal Delusion: A Case Report Involving a Male Patient

Hashimoto’s encephalopathy (HE) is a rare autoimmune disorder. It associates encephalopathy with autoimmune thyroiditis, presenting abnormal elevations of thyroid antibodies. It is more common in females. It can present with various symptoms, including seizures, myoclonus, psychosis, hallucinations, and mood disturbances. Hypochondriacal delusion is an unusual clinical presentation of this disorder. The authors report a case of HE in a male patient whose clinical presentation was dominated by hypochondriacal delusion. The absence of response to antipsychotics, high serum antithyroid peroxidase antibodiesof about 199 UI/ml, the normality of magnetic resonance imaging, and improvement with corticosteroids confirmed the diagnosis. This neuroendocrine disorder is often misdiagnosed and it represents a diagnostic challenge for clinicians. It should be considered in patients presenting a refractory or an atypical neuropsychiatric disorder and having a family history of autoimmune disease.

Moderators and mediators of antipsychotic response in delusional disorder: Further steps are needed

Delusional disorder (DD) has been traditionally considered a relatively rare and treatment-resistant psychotic disorder. In the last decade, increasing attention has focused on therapeutic outcomes of individuals affected by this disorder. The aim of this paper is to provide a synthesis of the literature addressing two very important questions arising from DD research: (1) For which patients with DD do antipsychotic medications work best (the moderators of response); and (2) What variables best explain the relationship between such treatments and their effectiveness (the mediators of response). We searched PubMed and Google Scholar databases for English, German, French and Spanish language papers published since 2000. We also included a few classic earlier papers addressing this topic. Variables potentially moderating antipsychotic response in DD are gender, reproductive status, age, duration of illness, the presence of comorbidity (especially psychiatric comorbidity) and its treatment, brain structure, and genetics of neurochemical receptors and drug metabolizing enzymes. Antipsychotic and hormonal blood levels during treatment, as well as functional brain changes, are potential mediating variables. Some, but not all, patients with DD benefit from antipsychotic treatment. Understanding the circumstances under which treatment works best can serve to guide optimal management.

Left cerebral cortex complexity differences in sporadic healthy individuals with auditory verbal hallucinations: A pilot study

In the present pilot study, we aimed to characterize the brain surface differences between 42 sporadic healthy individuals with AVHs (Hi-AVHs) and 50 healthy individuals without AVHs. The Auditory Hallucinations Rating Scale (AHRS) was used to assess the severity of AVHs, while the gyrification index and fractal dimensions were used to evaluate cerebral cortex complexity. We observed a significant increase of the gyrification index was located in the left superior temporal gyrus, the left temporoparietal junction, the left superior frontal gyrus, and the left parietal lobe. The fractal dimensions had significantly increased in the left Wernicke's area, the left Broca's areas and the left parietal lobe. Our pilot findings indicated gyrification index and fractal dimensions differences were only located in the left hemisphere between the groups of Hi-with and without AVHs. However, these differences did not correlate with the AVHs symptoms, and the non-hallucinating healthy individuals did not demonstrate corresponding reverse changes; hence we cannot postulate that cerebral cortex complexity alterations are related to AVHs. Our pilot study provides a clue for further studies aimed at investigating the brain features of Hi-AVHs.

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

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.

Reframing delusional infestation: perspectives on unresolved puzzles

Delusional infestation (DI), a debilitating psychocutaneous condition, featured as a false fixed belief of being infested accompanied by somatosensory abnormality, behavior alteration, and cognitive impairment. Although management of primary causes and pharmacotherapy with antipsychotics and/or antidepressants can help to alleviate symptoms in most patients, the underlying etiology of DI still remains unclear. Morgellons disease (MD), characterized by the presence of cutaneous filaments projected from or embedded in skin, is also a polemic issue because of its relationship with spirochetal infection. This review aims to discuss the following topics that currently confuse our understandings of DI: 1) the relationship of real/sham “infestation” with DI/MD; 2) behavior alterations, such as self-inflicted trauma; 3) neuroimaging abnormality and disturbance in neurotransmitter systems; and 4) impaired insight in patients with this disease. In discussion, we try to propose a multifactorial approach to the final diagnosis of DI/MD. Future studies exploring the neurobiological etiology of DI/MD are warranted.

History of Morgellons disease: from delusion to definition

Morgellons disease (MD) is a skin condition characterized by the presence of multicolored filaments that lie under, are embedded in, or project from skin. Although the condition may have a longer history, disease matching the above description was first reported in the US in 2002. Since that time, the condition that we know as MD has become a polemic topic. Because individuals afflicted with the disease may have crawling or stinging sensations and sometimes believe they have an insect or parasite infestation, most medical practitioners consider MD a purely delusional disorder. Clinical studies supporting the hypothesis that MD is exclusively delusional in origin have considerable methodological flaws and often neglect the fact that mental disorders can result from underlying somatic illness. In contrast, rigorous experimental investigations show that this skin affliction results from a physiological response to the presence of an infectious agent. Recent studies from that point of view show an association between MD and spirochetal infection in humans, cattle, and dogs. These investigations have determined that the cutaneous filaments are not implanted textile fibers, but are composed of the cellular proteins keratin and collagen and result from overproduction of these filaments in response to spirochetal infection. Further studies of the genetics, pathogenesis, and treatment of MD are warranted.