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.

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

BACKGROUND

Monothematic delusional disorders are characterized by a single tenacious belief. They provide a great opportunity to study underlying brain structures in the absence of confounding symptoms that accompany delusions in schizophrenia. Delusional beliefs include persecution, jealousy or somatic delusions including infestation. It is unclear whether specific delusional content is associated with distinct neural substrates.

METHODS

We used magnetic resonance imaging in patients presenting with somatic vs. non-somatic delusional disorders. Patients with delusional infestation (DI, n=18), and individuals with non-somatic delusional disorders (n=19) were included, together with healthy volunteers (n=20). Uni- and multivariate techniques for structural data analysis were applied to provide a comprehensive characterization of abnormal brain volume at both the regional and neural network level.

RESULTS

Patients with DI showed lower gray matter volume in thalamic, striatal (putamen), insular and medial prefrontal brain regions in contrast to non-somatic delusional disorders and healthy controls. Importantly, these differences were consistently detected at regional and network level. Compared to healthy controls, patients with delusional disorders other than DI showed lower gray matter volume in temporal cortical regions.

CONCLUSION

The data support the notion that dysfunctional somatosensory and peripersonal networks could mediate somatic delusions in patients with DI in contrast to delusional disorders without somatic content. The data also suggest putative content-specific neural signatures in delusional disorders and in delusion formation per se.

Cortical features of distinct developmental trajectories in patients with delusional infestation

BACKGROUND

Although there is strong neuroimaging evidence that cortical alterations are a core feature of schizophrenia spectrum disorders, it still remains unclear to what extent such abnormalities occur in monothematic delusional disorders. In individuals with delusional infestation (DI), the delusional belief to be infested with pathogens, previous structural MRI studies have shown prefrontal, temporal, parietal, insular, thalamic and striatal gray matter volume changes. Differential contributions of cortical features of evolutionary and genetic origin (such as cortical thickness, area and folding) which may distinctly contribute to DI pathophysiology are unclear at present.

METHODS

In this study, 18 patients with DI and 20 healthy controls (HC) underwent MRI scanning at 1.0T. Using surface-based analyses we calculated cortical thickness, surface area and local gyrification index (LGI). Whole-brain differences between patients and controls were investigated.

RESULTS

Surface analyses revealed frontoparietal patterns exhibiting altered cortical thickness, surface area and LGI in DI patients compared to controls. Higher cortical thickness was found in the right medial orbitofrontal cortex (p<0.05, cluster-wise probability [CWP] corrected). Smaller surface area in patients was found in the left inferior temporal gyrus, the precuneus, the pars orbitalis of the right frontal gyrus, and the lingual gyrus (p<0.05, CWP corr.). Lower LGI was found in the left postcentral, bilateral precentral, right middle temporal, inferior parietal, and superior parietal gyri (p<0.01, CWP corr.).

CONCLUSION

This study lends further support to the hypothesis that cortical features of distinct evolutionary and genetic origin differently contribute to the pathogenesis of delusional disorders. Regions in which atrophy was observed are part of neural circuits associated with perception, visuospatial control and self-awareness. The data are in line with the notion of a content-specific neural signature of DI.

Quality of life of children and adolescents with congenital anorectal malformations

anorectal malformations an at first glance invisible disorder - triggers the affected children and young people and their parents strong unease and is therefore often concealed and secretive. The problems are not less if the affected children grown up. Incontinence can affect quality of life and massive psychosocial developmental disorders can arrive (Jenetzky & Black 2008). Affected children and adolescents must make diets, they suffer from abdominal pain, incontinence and constipation, feel impaired in their body image and often they have feelings of fear and shame. In the social sphere, the children have to get difficulties to get in contact with their classmates and they are in school often absent or distracted (Grano et al. 2013). Objective: The aim of the present literature review is to describe the quality of life of children and adolescents with anorectal malformations and show developmental change in physical, psychological and social area. Method: To answer the question, a literature search was conducted. For this the relevant databases PubMed". " CINAHL with full text", ,,PsycInfo" and ,,Cochrane" were used. Results: The literature research shows, that children and young people with anorectal malformations have a worse quality of life than their healthy peers. They are ashamed, feel different than others and are afraid that they smell badly, They see themselves as unattractive and are often dissatisfied with their bodies. Among the adolescents there are significant gender differences: female adolescents, whether health or with anorectal malformations, have a worse quality of life than male adolescents (Michel et al 2009, cited by Grano et al 2013). Obviously pubertal development specificities of the two genders are responsible for this result (Patton et al. 2007, Petersen et al. 1991, cited in Grano et al. 2013). Children with fecal incontinence are in their behavior more prominent than their healthy peers and have more psychological/ psychosocial problems as their classmates in the exercise of activities of daily living, for example during routine school activities, during sports or if they say with friends (Hamid et al. 2007, cited by Grano et al. 2012). Conclusion: The multiple problems in the social, physical and psychological area make it necessary for children and adolescents with anorectal malformations to get early support (bowel management program, psychologist, group therapy). For example, affected children may begin already with 3¹/₂ years with a bowel management program to prevent negative consequences and/or to avoid social exclusion (Bischoff et al. 2009. cited in Grano et al. 2012). For parents, it is important that they learn to accept the child's illness and to help the children to cope their illness better. With this support in childhood it will be possible to accept the disease better and to integrate it into their self-image (Schmidt et al. 2010).

Delusional parasitosis and the dopamine transporter. A new insight of etiology?

Delusional parasitosis (DP) is a psychotic condition in which a person has the unshakeable and mistaken belief (delusion) and/or aberrant perception (hallucination) of being infested with parasites. The disorder will be usually classified in a primary DP-group without a detectable cause (so-called pure forms), while secondary DP-groups are associated with general organic conditions, psychiatric illnesses and drugs (substance induced). Etiology and pathophysiology of DP remain however unknown. In the present paper we hypothesize for the first time a decreased striatal dopamine transporter (DAT)-functioning (corresponding with an increased extracellular dopamine-level) as etiologic condition for DP (primary and secondary groups). The DAT as key regulator of the dopamine-reuptake in the human brain is well known (regulation of the extracellular dopamine concentration). It is a presynaptic plasma membrane protein highly dense represented in the striatum. The hypothesis of a decreased DAT-functioning as etiologic condition by DP is revealed in case reports which show that DAT-inhibitors, such as cocaine, pemoline, methylphenidate and other amphetamine-derivatives can induce the clinical expression of DP. Several other associated causes of secondary DP-groups (medications, parkinson, chorea huntington, multiple system atrophy, diabetes, cerebrovascular diseases, alcoholism, traumatic brain injury, hyperuricemia, human immunodeficiency virus, iron deficiency, schizophrenia, depression) suggest that the clinical expression of DP may be related to a decreased striatal DAT-functioning (blocking, reduced ligand binding, reduced density, reduced activity). Our examined DP-cases (2-females) show means of magnetic resonance imaging a structurally damaged striatum. Furthermore, we presume that by the primary DP-group, the physiologically age-related decline of the DAT-density is pathologically elevated. Based on this hypothesis we show in the present paper the relation between DP and decreased striatal DAT-functioning, trying to give a new insight into the pathophysiologically mechanism involved. The hypothesis provides supporting evidence that increased levels of extracellular dopamine in the striatum of DP-patients is likely to be the result of decreased DAT-functioning and not increased rates of release. The hypothesis can be investigated simply by dopamine transporter imaging in patients with DP.

[Neuropsychiatric bases of the methylphenidate-therapy of the attention deficit/hyperactivity disorder (ADHD)]

High prevalence and high co-morbidity rates with frequently aggravating psychosocial problems make the attention-deficit/hyperactivity disorder (ADHD) of children, adolescents and adults an important target for research and healthcare. Recent findings suggest a dopaminergic fronto-striatal information processing deficit in ADHD-patients (executive functions). This review summarizes and presents, in the context of recent studies (MRI, f-MRI, PET, SPECT, Mapping Genes) the neurobiochemical bases of the methylphenidate-therapy, clinically successfully applied since almost one half century by the ADHD. The increased striatal dopamine transporter density by the ADHD-methylphenidate-responder is reported as a scientifically sound and useful clinical working model.

Identification with peers as a strategy to muddle through the troubles of the adolescent years

This study was designed to explore critical events during adolescence and coping processes as dependent, first, on the relationship with peers, and second, on the type of peer-groups teenagers join. In all, 75 young people, members of four street groups and two religious groups, were given a questionnaire assessing identification with their peers and demographic characteristics, and then interviewed about critical events. The results show that the nature of the group individuals join is of minor importance, whereas the relationship established with peers is crucial: highly identified subjects not only more often join their peers but seem to derive more profit from interactions with people in general, both peers, friends, and parents. The peer-group is important, not to substitute for contacts with the family or other persons, but as a social entity to fill a vacuum during adolescent years.