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PubMedDate not supplied

Recurrence of hallucinations in consecutive episodes of schizophrenia and affective disorder.

48 patients with episodic psychosis (18 schizophrenia, 30 MDP) were studied to examine whether they had similar hallucinations in consecutive episodes. 34 cases reported hallucinations, 23 of whom had hallucinations in consecutive episodes. In 22 of these 23 cases, the same type of hallucination (in the same sense organ modality) recurred. A recurrence of similar content was found in nearly half of the cases. In cases in whom the hallucinatory content persisted, however, there was no persistence of delusional content. Similar neurophysiological disturbances in similar neuroanatomical regions may result in the persistence of the same hallucinations.

Adolescent↗
PubMedDate not supplied

Hallucinations in Latino psychiatric outpatients: a preliminary investigation.

Accuracy of diagnosis and efficacy of treatment depend on recognition of cultural variation in symptomatology of mental illness. Caribbean Latinos have been observed to present in outpatient settings with a higher than expected prevalence of hallucinations; however little is known about this phenomenon and whether it reflects psychotic illness. This study is a retrospective record review of 54 Spanish-speaking psychiatric outpatients who were evaluated in their own language. Demographic and clinical data were extracted from the records and relationships to hallucinations were examined. Of the total sample, 46% reported hallucinations, and 84% of these were simple (e.g., hearing one's name called). Thought disorder was diagnosed in only 9% of the sample. Caribbean Latinos presented to this outpatient mental health setting with a high rate of perceptual symptoms in the absence of other signs of psychosis. Since hallucinations are known to be nonspecific, the symptoms reported in this patient sample are best understood as nonpsychotic hallucinations. Further research is necessary to clarify the epidemiological and cultural aspects of this phenomenon, and to guide treatment.

Adult↗
PubMed2004

The clinical spectrum of musical hallucinations.

Musical hallucinations are a well known although rare phenomenon in neurological and psychiatric patients. Many case reports have been published to date. However, an accepted common theory on the classification and on the pathophysiology of musical hallucinations is still missing. We analysed all cases published to date, including two own cases, with respect to their demographic and clinical features and to the possible pathomechanisms underlying the hallucinations. In total, 132 cases could be analysed statistically and separated into five groups according to their aetiology (hypacusis; psychiatric disorder; focal brain lesion; epilepsy; intoxication). There was a female preponderance of 70% and a mean age of 61.5 years. Patients with focal brain lesions were significantly younger than the other groups, the hemisphere of the lesion did not play a major role. No systematic studies on treatment are available. However, anticonvulsant and antidepressive substances were reported to be effective most consistently. The pathophysiology of musical hallucinations is discussed considering the theories of deafferentiation including the concept of auditory Charles-Bonnet syndrome, of sensory auditory deprivation, of parasitic memory, and of spontaneous activity in a cognitive network module. In conclusion, musical hallucinations are a phenomenon with heterogeneous clinical and pathophysiological backgrounds.

Adult↗
PubMed2006

Computerized binary scale of auditory speech hallucinations (cbSASH).

BACKGROUND: Evidence indicates that the neuropathology of auditory verbal hallucinations (AVH) varies according to their phenomenological characteristics. Therefore, AVH should be subgrouped accordingly in hallucinations research. As evaluation of these characteristics depends entirely on the patient report, obtaining measurement of the reliability of these reports is crucial. METHOD: A computerized binary scale of auditory speech hallucinations (cbSASH) was developed to evaluate the phenomenology of AVH. It includes two subscales (inconsistency and malingering) to assess the reliability of the patient report. The cbSASH was administered along with MMPI-2, a general psychopathology scale, which includes similar validity subscales. Thirty-four psychotic patients with history of AVH were enrolled in this study. RESULTS: The scores on the inconsistency and malingering subscales of the cbSASH were correlated with the scores on the corresponding validity subscales in the MMPI-2. The combination of the malingering and inconsistency subscales provided robust measures of the reliability and ability of the patients' descriptions of their hallucinations. CONCLUSION: The cbSASH provides a reliable and comprehensive evaluation of the phenomenology of AVH. Consequently, it is possible to subgroup patients according to the characteristics of their hallucinations. This refinement of AVH phenotypes could reduce the noise and inconsistency noted in AVH and psychosis research.

Adult↗
PubMed2000

Visual hallucinations immediately after macular photocoagulation.

PURPOSE: To evaluate the incidence of visual hallucinations after macular photocoagulation for choroidal neovascularization. METHODS: After macular photocoagulation for choroidal neovascularization, 60 consecutive patients were asked to respond to an orally administered questionnaire. RESULTS: Twenty-seven patients (45%) described photopsias, flashing lights of various colors. Ten additional patients (16.6%) also described structured hallucinations, including known or unknown faces, flowers, and geometric patterns, which occurred hours or a few days after photocoagulation. Patients with structured hallucinations were older (P =.04) and more often had subfoveal choroidal neovascularization (P =.005) and severe macular disease in both eyes or at least in the treated eye (P =.01). CONCLUSIONS: Visual hallucinations appear to be a frequent, albeit unrecognized, side effect of macular photocoagulation of choroidal neovascularization. The provision of proper information to patients may avoid concern about a psychiatric origin of their hallucinations.

Adult↗
PubMed2000

Intrusive thoughts and auditory hallucinations: a comparative study of intrusions in psychosis.

Several theories of auditory hallucinations implicate the involvement of intrusive thoughts and other theories suggest that the interpretation of voices determines the distress associated with them. This study tested the hypotheses that patients who experience auditory hallucinations will experience more intrusive thoughts and be more distressed by them and interpret them as more uncontrollable and unacceptable than the control groups. It also examines whether the interpretation of hallucinations is associated with the distress caused by them and whether there are differences in the way that patients respond to and interpret their thoughts and voices. A questionnaire examining the frequency of intrusive thoughts and the reactions to them was administered to a group of patients with a diagnosis of schizophrenia who experienced auditory hallucinations, a psychiatric control group and a non-patient control group. In addition, the patients in the first group completed a similar questionnaire in relation to their voices. Analyses of covariance showed that patients who experienced auditory hallucinations had more intrusive thoughts than the control groups and that they found their intrusive thoughts more distressing, uncontrollable and unacceptable than the control groups. Correlational analyses revealed that patients' interpretations of their voices were associated with the measures of distress in relation to them. Repeated measures analyses of covariance found no differences between thoughts and voices on the dimensions assessed. The theoretical and clinical implications of these findings are discussed.

Adult↗
PubMed1999

Transcranial magnetic stimulation of left temporoparietal cortex in three patients reporting hallucinated "voices".

BACKGROUND: Prior studies suggest that auditory hallucinations of "voices" arise from activation of speech perception areas of the cerebral cortex. Low frequency transcranial magnetic stimulation (TMS) can reduce cortical activation. METHODS: We have studied three schizophrenic patients reporting persistent auditory hallucinations to determine if low frequency TMS could curtail these experiences. One hertz stimulation of left temporoparietal cortex was compared with sham stimulation using a double-blind, cross-over design. RESULTS: All three patients demonstrated greater improvement in hallucination severity following active stimulation compared to sham stimulation. Two of the three patients reported near total cessation of hallucinations for > or = 2 weeks. CONCLUSIONS: TMS may advance our understanding of the mechanism and treatment of auditory hallucinations.

Adult↗
PubMedDate not supplied

Complex visual hallucinations in the visually impaired: the Charles Bonnet Syndrome.

Visually impaired patients may experience complex visual hallucinations, a condition known as the Charles Bonnet Syndrome. Patients usually possess insight into the unreality of their visual experiences, which are commonly pleasant but may sometimes cause distress. The hallucinations consist of well-defined, organized, and clear images over which the subject has little control. It is believed that they represent release phenomena due to de-afferentation of the visual association areas of the cerebral cortex, leading to a form of phantom vision. Cognitive defects, social isolation, and sensory deprivation have also been implicated in the etiology of this condition. This condition, which is most common in the elderly, frequently goes unrecognized in clinical practice, due to both lack of awareness among doctors and patients' reluctance to admit to hallucinatory experiences, for fear of being labeled mentally unstable. Furthermore, patients who comprehend the unreality of their hallucinations may be distressed by the real fear of imminent insanity. Sensitive and sympathetic history taking is essential to ascertain the existence of hallucinations. Reassurance and explanation that the visions are benign and do not signify mental illness have a powerful therapeutic effect. Hallucinatory activity may terminate spontaneously, on improving visual function or on addressing social isolation. There is no universally effective drug treatment but anticonvulsants may play a limited role in aborting the hallucinations. Physician awareness and empathy are the cornerstones of management.

Anticonvulsants↗
PubMed1995

Abnormal monitoring of inner speech: a physiological basis for auditory hallucinations.

Auditory verbal hallucinations ("voices") are thought to arise from a disorder of inner speech (thinking in words). We examined the neural correlates of tasks which involve inner speech in subjects with schizophrenia who hear voices (hallucinators), subjects with schizophrenia who do not (nonhallucinators), and normal controls. There were no differences between hallucinators and controls in regional cerebral blood flow during thinking in sentences. However, when imagining sentences being spoken in another person's voice--which entails both the generation and monitoring of inner speech--hallucinators had a normal left frontal response, but reduced activation in the left middle temporal gyrus and the rostral supplementary motor area, regions which were activated by both normal subjects and nonhallucinators (p < 0.001). These findings suggest that a predisposition to verbal hallucinations is associated with a failure to activate areas concerned with the monitoring of inner speech.

Adult↗
PubMed1998

Effects of a negative visual hypnotic hallucination on ERPs and reaction times.

The study of changes in ERPs provoked by negative hypnotic hallucinations has thus far yielded contradictory results. Most previous studies have failed to separate specific changes in the processing of the hallucinated stimuli from non-specific changes in arousal due to hypnosis. The present study addresses this issue with the combination of two experimental effects in the task designed to test the hallucination: the noise-compatibility effect and the Simon effect. A choice reaction task was used in which targets appearing at either side of a screen were defined by color and were accompanied by irrelevant noise, and a negative hallucination suggestion was given for noise stimuli. Four highly hypnotizable subjects performed the task on two separate occasions, with and without the suggestion. Increases in reaction times and P300 latencies were found as a function of noise and spatial stimulus-response (SR) incompatibility (Simon effect). Suggestion decreased the response times for all types of trials non-significantly, and it decreased significantly those of left-hand responses. On the other hand, suggestion reduced the increase in P300 latencies in noise-incompatible trials, but did not influence the Simon effect. This result indicates a specific effect of suggestion in the processing of hallucinated stimuli, which is consistent with the hallucinatory experience reported by the subjects.

Adult↗
PubMed2002

Auditory hallucinations: hypothesis in the context of spread spectrum communications.

Among patients with mental disorders there are some who experience auditory hallucinations. Auditory hallucinations are often associated with schizophrenia. However, there are studies that indicate that other patients with affective disorders may also experience auditory hallucinations. The mechanism of auditory hallucinations is not known. In view of the results of biochemical studies of the hearing mechanisms and spread spectrum communications, we present a hypothesis that individuals who experience auditory hallucinations are perhaps receiving and processing signals in a different way. Treatment with pharmacologically active compounds improves the condition of patients with mental disorders by changing the brain function and perhaps the presence of these compounds may also be modifying the way in which incoming signals of varying frequencies are processed.

Hallucinations↗
PubMed1999

Activation of Heschl's gyrus during auditory hallucinations.

Apart from being a common feature of mental illness, auditory hallucinations provide an intriguing model for the study of internally generated sensory perceptions that are attributed to external sources. Until now, the knowledge about the cortical network that supports such hallucinations has been restricted by methodological limitations. Here, we describe an experiment with paranoid schizophrenic patients whose on- and offset of auditory hallucinations could be monitored within one functional magnetic resonance imaging (fMRI) session. We demonstrate an increase of the blood oxygen level-dependent (BOLD) signal in Heschl's gyrus during the patients' hallucinations. Our results provide direct evidence of the involvement of primary auditory areas in auditory verbal hallucinations and establish novel constraints for psychopathological models.

Acoustic Stimulation↗
PubMed2000

The functional anatomy of auditory hallucinations in schizophrenia.

We used continuous whole brain functional magnetic resonance imaging (fMRI) with a 3-T magnet to map the cerebral activation associated with auditory hallucinations in four subjects with schizophrenia. The subjects experienced episodes of hallucination whilst in the scanner so that periods of hallucination could be compared with periods of rest in the same individuals. Group analysis demonstrated shared areas of activation in right and left superior temporal gyri, left inferior parietal cortex and left middle frontal gyrus. When the data were examined on an individual basis, the temporal cortex and prefrontal cortex areas were activated during episodes of hallucination in all four subjects. These findings support the theory that auditory hallucination reflects abnormal activation of normal auditory pathways.

Adult↗
PubMed2002

Right prefrontal rTMS treatment for refractory auditory command hallucinations - a neuroSPECT assisted case study.

Auditory command hallucinations probably arise from the patient's failure to monitor his/her own 'inner speech', which is connected to activation of speech perception areas of the left cerebral cortex and to various degrees of dysfunction of cortical circuits involved in schizophrenia as supported by functional brain imaging. We hypothesized that rapid transcranial magnetic stimulation (rTMS), by increasing cortical activation of the right prefrontal brain region, would bring about a reduction of the hallucinations. We report our first schizophrenic patient affected with refractory command hallucinations treated with 10 Hz rTMS. Treatment was performed over the right dorsolateral prefrontal cortex, with 1200 magnetic stimulations administered daily for 20 days at 90% motor threshold. Regional cerebral blood flow changes were monitored with neuroSPECT. Clinical evaluation and scores on the Positive and Negative Symptoms Scale and the Brief Psychiatric Rating Scale demonstrated a global improvement in the patient's condition, with no change in the intensity and frequency of the hallucinations. NeuroSPECT performed at intervals during and after treatment indicated a general improvement in cerebral perfusion. We conclude that right prefrontal rTMS may induce a general clinical improvement of schizophrenic brain function, without directly influencing the mechanism involved in auditory command hallucinations.

Attention↗
PubMed1999

Neuroimaging of hallucinations: a review of the literature.

While hallucinations have been described for over two millennia, their cause remains unclear. Brain-based models suggest that abnormal cerebral excitation and a lack of normal cerebral inhibition may play primary roles, but evaluation of these hypotheses has been hampered by difficulty in studying the hallucinatory state. Recent advances in neuroimaging have provided researchers with tools to study a variety of mental states, including hallucinations. We review the literature regarding the structural and functional neural correlates of hallucinations. Despite small sample sizes and methodological differences, several studies describe similar results: hallucinations are associated with sensory modality-specific activation in cerebral areas involved in normal sensory processing. Furthermore, neural activation may be specifically related to distinct phenomenological features of the hallucinatory experience. Further work is needed to better understand the neural basis of hallucinations.

Adult↗
PubMed1996

The auditory hallucination: a phenomenological survey.

A comprehensive semi-structured questionnaire was administered to 100 psychotic patients who had experienced auditory hallucinations. The aim was to extend the phenomenology of the hallucination into areas of both form and content and also to guide future theoretical development. All subjects heard 'voices' talking to or about them. The location of the voice, its characteristics and the nature of address were described. Precipitants and alleviating factors plus the effect of the hallucinations on the sufferer were identified. Other hallucinatory experiences, thought insertion and insight were examined for their inter-relationships. A pattern emerged of increasing complexity of the auditory-verbal hallucination over time by a process of accretion, with the addition of more voices and extended dialogues, and more intimacy between subject and voice. Such evolution seemed to relate to the lessening of distress and improved coping. These findings should inform both neurological and cognitive accounts of the pathogenesis of auditory hallucinations in psychotic disorders.

Adaptation, Psychological↗
PubMed2003

Misleading hallucinations in unrecognized narcolepsy.

OBJECTIVE: To describe psychosis-like hallucinatory states in unrecognized narcolepsy. METHOD: Two patients with hypnagogic/hypnapompic hallucinations are presented. RESULTS: Both patients had realistic and complex - multi-modal and scenic-daytime sexual hallucinations leading, in the first case, to a legal procedure because of false accusation, and in the second, to serious workplace conflicts. Both patients were convinced of the reality of their hallucinatory experiences but later both were able to recognize their hallucinatory character. Clinical data, a multiple sleep latency test, polysomnography, and HLA typing revealed that both patients suffered from narcolepsy. CONCLUSION: We suggest that in unrecognized narcolepsy with daytime hypnagogic/hypnapompic hallucinations the diagnostic procedure may mistakenly incline towards delusional psychoses. Daytime realistic hypnagogic/hypnapompic hallucinations may also have forensic consequences and mislead legal evaluation. Useful clinical features in differentiating narcolepsy from psychoses are: the presence of other narcoleptic symptoms, features of hallucinations, and response to adequate medication.

Adult↗
PubMed1990

The illusion of reality: a review and integration of psychological research on hallucinations.

Hallucinations are among the most severe and puzzling forms of psychopathology. Although usually regarded as first-rank symptoms of schizophrenia, they are found in a wide range of medical and psychiatric conditions. Moreover, a substantial minority of otherwise normal individuals report hallucinatory experiences. The purpose of this article is to review the considerable research into the cognitive mechanisms underlying (particularly psychotic) hallucinations that has been carried out and to integrate this research within a general framework. The available evidence suggests that hallucinations result from a failure of the metacognitive skills involved in discriminating between self-generated and external sources of information. It is likely that different aspects of these skills are implicated in different types of hallucinatory experiences. Further research should focus on specific metacognitive deficits associated with different types of hallucinations and on treatment strategies designed to train hallucinators to reattribute thoughts to themselves.

Cognition↗