SPECT neuroimaging in schizophrenia with religious delusions

Characteristic brain hypoperfusion by 99mTc-ECD single photon emission computed tomography (SPECT) in patients with the first-episode schizophrenia

Objective

In this study, we evaluated brain perfusion in patients with first-episode medicated schizophrenia using the new analytical method, statistical parametric mapping (SPM) applied to single photon emission computed tomography (SPECT).

Method

We performed SPECT with 99-Tc-ethyl cysteinate dimer (99mTc-ECD) of the brain and magnetic resonance imaging (MRI) in patients with schizophrenia (n = 30) and control subjects matched for age and gender (n = 37). A voxel-by-voxel group analysis was performed using SPM2 (Z > 3.0, P < 0.001, uncorrected for multiple comparisons).

Result

In comparison with control subjects, the volumes of the bilateral frontal areas were found to be decreased on MRI. Blood flow was found to be reduced in the bilateral temporal areas in the patients with schizophrenia on SPECT.

Conclusion

In this study, patients with first-episode schizophrenia appeared to have significant bilateral temporal hypoperfusion, although temporal volumes were not significantly decreased in comparison with control subjects. Abnormality of temporal lobe blood flow in schizophrenia may show that functional changes occur earlier than structural changes, and may assist in the diagnosis of schizophrenia.

The influence of religious activity and polygenic schizophrenia risk on religious delusions in schizophrenia

BACKGROUND

Religious delusions are a common symptom in patients experiencing psychosis, with varying prevalence rates of religious delusions across cultures and societies. To enhance our knowledge of this distinct psychotic feature, we investigated the mutually-adjusted association of genetic and environmental factors with occurrence of religious delusions.

METHODS

We studied 262 adult German patients with schizophrenia or schizoaffective disorder. Association with lifetime occurrence of religious delusions was tested by multiple logistic regression for the following putative predictors: self-reported degree of religious activity, DSM-IV diagnosis, sex, age, education level, marital status, presence of acute delusion at the time of interview and an individual polygenic schizophrenia-risk score (SZ-PRS, available in 239 subjects).

RESULTS

Of the 262 patients, 101 (39%) had experienced religious delusions. The risk of experiencing religious delusions was significantly increased in patients with strong religious activity compared to patients without religious affiliation (OR = 3.6, p = 0.010). Low or moderate religious activity had no significant effect. The same analysis including the SZ-PRS confirmed the effect of high religious activity on occurrence of religious delusions (OR = 4.1, p = 0.008). Additionally, the risk of experiencing religious delusions increased with higher SZ-PRS (OR 1.4, p = 0.020, using pT = 0.05 for SZ-PRS calculation). None of the other variables were significantly associated with lifetime occurrence of religious delusions.

CONCLUSIONS

Our results suggest that strong religious activity and high SZ-PRS are independent risk factors for the occurrence of religious delusions in schizophrenia and schizoaffective disorder.

Experiences with 99mTc-HMPAO in a Diagnostic Pathway for Violent Patients with Schizophrenic Spectrum Disorders

BACKGROUND AND OBJECTIVE

In a security ward we assessed the diagnostic contribution of single photon scintigraphy [SPECT] in our diagnostic pathway for patients with serious mental disease and a history of violence.

METHODS

Twenty patients were examined between 2012 and 2015 and the findings compared to those in nine patients with the same diagnosis, but no history of violence.

RESULTS

All violent patients had areas with reduced accumulation of 99mTc-HMPAO frontally and in the temporal lobe, in the non-violent group only two patients demonstrated these findings.

CONCLUSION

Traditionally, low accumulation of the tracer in SPECT is related to reduced perfusion of brain tissue. We discuss our findings in the light of other possible pathophysiological mechanisms.

Orbitofrontal cortex volume and intrinsic religiosity in non-clinical psychosis

Research indicates that religiosity plays a complex role in mental illness. Despite this link, little work has been done to clarify the role of religiosity in persons exhibiting non-clinical psychosis (NCP, individuals experiencing fleeting psychotic-like symptoms in the absence of a formal psychotic disorder). Further, there are no NCP investigations into whether abnormalities exist in brain structures that are associated with religiosity. Understanding these relationships in NCP is important to clarify the role of religiosity and brain structural anomalies in psychosis. Twenty individuals experiencing NCP and twenty controls were assessed for intrinsic religiosity (IR; motivation/commitment to religious beliefs and/or practices) using a well-validated self-report scale. Structural magnetic resonance imaging was used to determine volumes of the orbitofrontal cortex (OFC), a critical region that has been associated with increased religiosity. Results indicate that IR is elevated in the NCP group, and that these individuals exhibit bilateral volume reduction in both the lateral and medial OFC. Sample-wide correlations are non-significant, but show notable relationships between smaller OFC regions and increased IR. Significant negative relationships were found between OFC volume and depressive and negative symptoms. Overall, results suggest that brain abnormalities associated with NCP may also confer a heightened susceptibility for religiosity.

Neurobiological correlates of delusion: beyond the salience attribution hypothesis

Dopamine dysfunction is a mainstay of theories aimed to explain the neurobiological correlates of schizophrenia symptoms, particularly positive symptoms such as delusions and passivity phenomena. Based on studies revealing dopamine dysfunction in addiction research, it has been suggested that phasic or chaotic firing of dopaminergic neurons projecting to the (ventral) striatum attribute salience to otherwise irrelevant stimuli and thus contribute to delusional mood and delusion formation. Indeed, several neuroimaging studies revealed that neuronal encoding of usually irrelevant versus relevant stimuli is blunted in unmedicated schizophrenia patients, suggesting that some stimuli that are irrelevant for healthy controls acquire increased salience for psychotic patients. However, salience attribution per se may not suffice to explain anxieties and feelings of threat that often accompany paranoid ideation. Here, we suggest that beyond ventral striatal dysfunction, dopaminergic dysregulation in limbic areas such as the amygdala in interaction with prefrontal and temporal cortex may contribute to the formation of delusions and negative symptoms. Neuroleptic medication, on the other hand, appears to interfere with anticipation of reward in the ventral striatum and can thus contribute to secondary negative symptoms such as apathy and avolition.

A general neuropsychological model of delusion

INTRODUCTION

Neurocognitive accounts of delusion have traditionally highlighted perceptual misrepresentation, as the primary trigger in addition to other cognitive deficits that maintain the delusion. Here, a general neurocognitive model of delusional disorder (DSM-IV) is proposed, not so much based on perceptual or cognitive deficits after right hemisphere damage as on cognitive propensities, specifically excessive inferencing (especially jumping to conclusions) and excessive reference to the self, due to left hemisphere overactivity.

METHOD

The functional imaging, topographic EEG, and experimental imaging literatures on delusional disorder are reviewed, and 37 previously published cases of postunilateral lesion delusion (DSM-IV type, grandeur, persecution, jealousy, erotomania, or somatic), are reviewed and analysed multivariately.

RESULTS

Functional imaging and EEG topography data were slightly more indicative of left hemisphere overactivity in delusional disorder. In addition, 73% of the postunilateral lesion cases (χ(2)=7.8, p=.005) of delusional disorder (DSM-IV type) had a right hemisphere lesion, whereas only 27% had a left hemisphere lesion.

CONCLUSION

Left hemisphere release appears to be a more primary cause of delusional disorder than right hemisphere impairment, the latter merely entailing loss of inhibition of delusional beliefs. We propose that most patients with DSM-IV diagnoses of delusional disorder could be afflicted by excessive left hemisphere activity, but further research is necessary.

Imaging the deluded brain

Various factors contribute to the development and maintenance of delusions in the context of schizophrenic psychoses. Studies with functional and structural MRI were able to detect neurobiological correlates of paranoid symptoms. Consistent with the neurodevelopmental hypothesis of schizophrenic psychosis, which implies an early developmental disorder affecting temporo-limbic areas and resulting in a disinhibition of striatal dopamine release, current imaging studies point towards the involvement of temporo-limbic and frontal dysfunction in delusion formation. In line with this, a specific role of dopamine as a neuromodulator in delusion formation is being discussed. Finally, mechanisms relevant to delusion formation appear to involve cognitive processes such as biases of attribution with regard to emotionally salient events as well as attentional biases during the perception of affective stimuli.

Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition symptoms of mania: which one(s) result(s) more often from right than left hemisphere lesions?

Previously published single case reports of patients with a unilateral lesion were assembled. After the lesion, each of the 244 cases presented at least one of the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) symptoms of a manic episode, namely, elated or irritable mood, grandiosity, talkativeness, flight of ideas, hyperhedonism, reduced need for sleep, agitation, or distractibility (all optional in DSM-IV). As expected, the subgroup of 59 manic patients had a right hemisphere lesion far more often than a left one. However, this was also true of various sets of the nonmanic cases. Furthermore, elation was not the symptom most strongly associated with lesion side. Elation without mania was not significantly predicted by lesion side. However, talkativeness was strongly predicted by right lesion side whether in manic or nonmanic patients or even when the symptom was the only symptom observed. Agitation was consistently and robustly associated with right lesion side, but not completely distinctly so (it fell short of significance when not accompanied by elation or other symptoms). It is proposed that prevalence of right hemisphere lesions causing mania is primarily related to mental and behavioral disinhibition rather than a shift of mood and that it consists of release of left hemisphere influence.

The interface between religion and psychosis

OBJECTIVE

This paper aims to explore the interface between religion and psychosis, and to comment on its relevance in clinical practice.

METHOD

The context of religious psychotic phenomena is briefly discussed, leading to an examination of the biological substrates of religious experiences, the hypothesized process of religious psychotic symptom formation, and the clinical implications when assessing religious delusions. A PubMED search was conducted to identify original research and review articles of relevance to the discussion.

RESULTS

Religion is an enduring theme in psychosis, the understanding of which can be assisted by distinguishing between religion as a culture and religiosity as pathology. There are strong arguments for the involvement of temporolimbic instability in the generation of religious psychotic symptoms.

CONCLUSIONS

Psychosis can be conceptualized as the manifestation of aberrant perceptual and/or integrative processes. The prevalence of religion as a psychotic theme may be explained by its central cultural role, the implication of temporolimbic overactivity in the pathogenesis of some cases of psychosis, and the tendency to interpret intense or discrepant perceptual events as spiritual. In the clinical setting, the determination of religious delusions can be challenging at times. In addition to seeking advice on unfamiliar religions, a thorough assessment of the dimensions of religious beliefs and symptoms of neurocognitive dysfunction can be useful.

Left temporal perfusion associated with suspiciousness score on the Brief Psychiatric Rating Scale in schizophrenia

We evaluated the relationship between regional cerebral blood flow (rCBF) and clinical symptoms in patients with schizophrenia. Single photon emission computed tomography with N-isopropyl-p-[123I]iodoamphetamine (123I-IMP) was used to study 29 patients with schizophrenia. Clinical symptoms were assessed using the Brief Psychiatric Rating Scale (BPRS). We examined the correlation between rCBF and each BPRS item score using Statistical Parametric Mapping software. Corrected P-values < 0.05 were considered as statistically significant. The suspiciousness score on the BPRS was positively correlated with rCBF in the left inferior temporal gyrus. There was no significant correlation between rCBF and any other items of the BPRS. There was no significant correlation between rCBF and chlorpromazine-equivalent dosage. This analysis permits the quantitative assessment of the severity of persecutory delusions in relation to left temporal perfusion in patients with schizophrenia.

The role of the extrapersonal brain systems in religious activity

The neuropsychology of religious activity in normal and selected clinical populations is reviewed. Religious activity includes beliefs, experiences, and practice. Neuropsychological and functional imaging findings, many of which have derived from studies of experienced meditators, point to a ventral cortical axis for religious behavior, involving primarily the ventromedial temporal and frontal regions. Neuropharmacological studies generally point to dopaminergic activation as the leading neurochemical feature associated with religious activity. The ventral dopaminergic pathways involved in religious behavior most closely align with the action-extrapersonal system in the model of 3-D perceptual-motor interactions proposed by . These pathways are biased toward distant (especially upper) space and also mediate related extrapersonally dominated brain functions such as dreaming and hallucinations. Hyperreligiosity is a major feature of mania, obsessive-compulsive disorder, schizophrenia, temporal-lobe epilepsy and related disorders, in which the ventromedial dopaminergic systems are highly activated and exaggerated attentional or goal-directed behavior toward extrapersonal space occurs. The evolution of religion is linked to an expansion of dopaminergic systems in humans, brought about by changes in diet and other physiological influences.

Neuroscientific Psychophysiology: The International Organization of Psychophysiology (I.O.P.) associated with the United Nations (New York) in the 21st Century

This Presidential Address 2004 emphasizes the pivotal role of Psychophysiology as an integrated neuroscience with a panoply of electrophysiological and neuroimaging technologies for the establishment of methodologically crucial conceptual links for the understanding and mapping of brain functions pertaining to cognitive, emotional and motivational processes. Moreover, Psychophysiology's unique neuroscientific perspective by integrating functions of central and autonomic nervous systems with behavior in health and disease is underlined. Based on these developments, the progress of rigorous neuroscientific Clinical Psychophysiology offers possibilities for diagnosis, treatment and objective evaluation of therapeutic outcome in various pathological conditions.