Pathogenesis Of Auditory Hallucinations Research Articles

The role of the attachment relation in the pathogenesis of auditory hallucinations – literature overview

Objective: The purpose of the article is to provide an overview of the literature concerning the role of the attachment relation in the pathogenesis of auditory hallucinations. The article holistically integrates the knowledge about the attachment relation with cognitive and biological factors. Materials and method: The literature overview was compiled using the following databases: EBSCO, PsycINFO, PubMed, Google Scholar. The databases were searched using the following keywords: „secure”, „disorganized”, „epigenetic”, „genetic”, „auditory hallucinations” and the term „monoaminergic system”. These words were combined with the term „attachment style”. Results: The literature analysis suggests that neurobiological and cognitive factors mediate in the pathomechamism affiliating traumatic experience in the attachment relation with auditory hallucinations These include: dysregulation within the monoaminergic systems, atrophy of the temporal areas and cognitive distortions such as source monitoring errors and negative automatic thoughts. Discussion and conclusions: Cognitive dysfunctions along with hereditary genetic susceptibility to auditory hallucinations may constitute factors distorting the correct interpretation of traumatic intrusions of relational experience. Future research should verify to what extent auditory hallucinations are the memory marks of a relational trauma. Verification of these hypotheses will enable better understanding of the role of the attachment styles in the development of auditory hallucinations and the formation of convictions about them.

Alterations in innate immune defense distinguish first-episode schizophrenia patients from healthy controls.

Innate immune components involved in host defense have been implicated in schizophrenia (SCZ). However, studies exploring their clinical utility in SCZ diagnosis are limited. The main purpose of this study was to evaluate whether circulating endotoxin, high mobility group box 1 protein (HMGB1) and complement component 4 (C4) could act as peripheral biomarkers to distinguish first-episode schizophrenia (FES, n = 42) patients from healthy controls (HCs, n = 35) in associations with psychopathological symptoms and cognitive dysfunctions. Also, their changes after 8-week antipsychotic treatment were investigated. The Positive and Negative Syndrome Scale (PANSS), Psychotic Symptom Rating Scale (PSYRATS), and MATRICS Consensus Cognitive Battery (MCCB) were administered. Receiver operating characteristic (ROC) curves were conducted to evaluate the diagnostic effectiveness of the three biological indicators. Compared to HCs, levels of endotoxin, HMGB1, and C4 were remarkably increased in FES patients after controlling for age, gender, body mass index (BMI) and education years, and the combination of the three biomarkers demonstrated desirable diagnostic performance (AUC = 0.933). Moreover, the endotoxin level was positively correlated with the severity of auditory hallucinations. After 8 weeks of treatment, HMGB1 was decreased significantly in patients but still higher than that in HCs, whereas endotoxin and C4 did not change statistically. The baseline levels of endotoxin, HMGB1, and C4, as well as their changes were not associated with changes in any PANSS subscale score and total score. Our preliminary results suggest that a composite peripheral biomarker of endotoxin, HMGB1, and C4 may have accessory diagnostic value to distinguish SCZ patients from HCs. Additionally, endotoxin might be implicated in the pathogenesis of auditory hallucinations.

AUDITORY BRAINSTEM RESPONSE ABNORMALITIES IN SCHIZOPHRENIC PATIENTS WITH AUDITORY HALLUCINATIONS

Background : although the exact pathogenesis of auditory hallucinations is not yet known, some suggested the impairment of perception and processing of auditory information as a possible explanation. So, the aim of this study is to evaluate auditory pathways of schizophrenic patients using auditory brainstem responses (ABR). Methods : schizophrenic patients with auditory hallucinations and age and sex matched healthy non-relative controls were recruited in this case-control study. Scale for assessment of positive symptoms (SAPS) was used for rating the severity of hallucinations. Then, ABR recorded from all participants and the latencies of waves I, II, III, IV, V and inter-peak latencies (IPL) of waves I-III, III-V were analyzed on both sides. Chi squire and independent t tests were applied for statistical analysis. P-value≤0.05 was considered significant. Results : 39 patients and 35 controls were included. Latencies of waves III and V and IPL of III-V were significantly prolonged on the left side. Disease duration had no influence on the results. Conclusion : there is a link between abnormal ABRs and auditory hallucinations in schizophrenic patients that indicates dysfunction and abnormal asymmetry of auditory pathways in these patients.

Auditory hallucinations: Insights and questions from neuroimaging

Introduction. The human brain has the capacity to hallucinate but rarely, except in severe neuropsychiatric conditions such as schizophrenia, do they naturally predominate. The neural basis of auditory verbal hallucinations (AVHs) has been investigated using structural and functional neuroimaging techniques. So far, no studies have defined a model that explains why auditory hallucinations are perceived in the absence of an external stimulus.Methods. A selective literature review was undertaken specifically to focus on: (1) clinical phenomenology; (2) putative brain systems involved in the pathogenesis of auditory hallucinations as suggested by neuroimaging studies; (3) contributions and weaknesses of the neuroimaging findings in potentially bridging the gap between the neuroscience and phenomenology. Throughout, an attempt was made to ask questions as much as to answer them.Results. Functional domains implicated in the genesis of auditory verbal hallucinations include: (1) hearing and language; (2) “sense of reality”, including externality of voices; (3) attention and salience; (4) emotional response; (5) memory; (6) volition and self-monitoring; (7) impulse control. Each of these domains can be mapped onto neural “systems” that comprise components that overlap with brain regions known to activate during the experience of auditory hallucinationsConclusions. In the next phase of neuroimaging research into the pathogenesis of auditory hallucinations we need to examine component processes that lead to the patient's perception of them as real.

Locating voices in space: A perceptual model for auditory hallucinations?

Introduction. Auditory hallucinations are often perceived as being located in external auditory space (“outside the head”), like real auditory perceptions, but in the absence of a speaker or other external stimulus.Method. A selective literature review of the spatial phenomenology of auditory hallucinations and the cognitive neuroscience of locating real voices in external space was undertaken. An auditory-perceptual model of external auditory hallucinations was developed in healthy right-handed subjects using functional magnetic resonance imaging and the presentation of speech in virtual acoustic space.Results. Karl Jaspers inextricably linked “reality” and “externality” of auditory hallucinations. Although these two properties do not always occur simultaneously in hallucinating patients, the issue of “externality” is important from both a clinical and neuroscientific perspective. In an auditory-perceptual model of auditory hallucinations, association cortex in the left planum temporale is critically involved in the perception of real voices as located in external space. Right-sided voice stimuli are associated with greater neural response in the dominant (left) auditory cortex than left-sided stimuli. Subjects are better at identifying the spatial location of voices presented on the right than on the left.Conclusion. The auditory-perceptual model described helps identify candidate brain systems likely to be involved in the pathogenesis of auditory hallucinations in schizophrenia, and is distinct from other models, which use concepts of “internal monitoring” and “inner speech”. Its application, in the cognitive neuroscientific investigation of the phenomenology of auditory hallucinations, may shed further light on the mechanisms underlying this distressing experience.