摘要:

Delusional misidentification provides us with an excellent example of how it is necessary to take both organic brain disease and psychological processes into account when describing the development of mental symptoms. A model of delusional misidentification is proposed which was developed in an attempt to explain this interaction. The model is based on the events that occur during preconscious processing of perceptions. It predicts an inverse relationship between the presence of organic brain disease and the presence of paranoid delusions. This was tested using a retrospective analysis of case reports. A graded and inverse relationship between the degree of organic disturbance and the presence of paranoid delusions preceding the delusional misidentification was found. A satisfactory model of delusional misidentification syndromes must be able to acknowledge the way these two forces are able to interact.

ISSN:0254-4962    

DOI:10.1159/000284865

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Five hundred and seventy cases in 252 reports of the delusion of substitution yielded 200 cases with an organic contributor to the occurrence of the delusion. In 79 cases lateralization or localization could be determined, with lesions primarily in the left temporal or right frontal areas. Factors related to ‘feature recognition’, ‘familiarity’ and ‘reduplication’ could be found and are discussed in relation to the neurobehavioral features of the symptom.

ISSN:0254-4962    

DOI:10.1159/000284866

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Following a general review of the literature linking right hemisphere dysfunction to psychoses in general and Capgras delusion (CD) in particular, two studies are described that confirm the link. Study 1 revealed that, compared with matched psychiatric controls, 3 CD patients were particularly poor at matching pairs of faces shown briefly in the left visual field – which implies dysfunctioning right hemisphere performance. However there was no difference in performance when the faces appeared bilaterally, which fails to support the hypothesis that poor interhemispheric communication may give rise to CD. The second study involved tests of face memory and word memory. CD and other delusional misidentification groups scored markedly low on the face test, again implying right hemisphere deficit. Finally, a model of what may be the right hemisphere mechanism giving rise to CD was explored. This assumes two routes to face recognition, ventral and dorsal. It is argued that exclusive damage to the former may cause prosopagnosia and problems in the latter may give rise to the symptoms of CD.

ISSN:0254-4962    

DOI:10.1159/000284867

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

In the Capgras syndrome (CS) there is a natural dissociation between recognition and identification and it deserves to be designated as an agnosia of identification. Joseph Capgras who first introduced this concept of agnosia, also suggested that the syndrome might be studied within the framework of ‘méconnaissance systématique’ (translated here as systematic unawareness), thus anticipating a type of interpretation in which the basis of CS (and other delusional misidentification syndromes) would be a lack of corporeal and/or egocentric space awareness. From two examples, it is suggested that the basic phenomenon of unawareness may be due to sensory deprivation. A particular process of awareness concerning personal objects is hypothesized which would explain the specific delusion of reduplication that occurs when these objects are misidentified.

ISSN:0254-4962    

DOI:10.1159/000284868

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Delusional misidentification symptoms (DMS) are common in Alzheimer’s disease (AD) and they are frequent sources of serious distress for patients and particularly caregivers. We observed DMS in around 30% of the patients with moderate to severe AD in two independent prospective studies; the Capgras type, phantom boarder, mirror and TV DMS were found most frequently. Patients with DMS showed increased EEG delta-power over the right hemisphere, their CT scans showed more severe right frontal lobe atrophy, and the number of their pyramidal cells in area CA1 was lower than in the patients without DMS. This may indicate that the development of DMS in AD can be promoted by certain patterns of brain degeneration which affect systems relevant to the recognition and updating of memories, while verbal skills may initially be left largely intact.

ISSN:0254-4962    

DOI:10.1159/000284869

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

The case of a young woman with a disorder involving Capgras syndrome, Frégoli syndrome, intermetamorphosis, and the subjective-doubles syndrome is reported. Neuropsychological assessment showed a low efficiency in the complex visuospatial organization tasks and in non-verbal memory. MRI found a left lenticular hypodensity, and two PET scans performed in the symptomatic and recovered states showed significant changes and asymmetries in cerebral glucose metabolism in the frontal, parietal, and subcortical regions. These findings are discussed with respect to recent models of delusional mis-identification syndromes.

ISSN:0254-4962    

DOI:10.1159/000284870

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Capgras’ delusion (CD) may be secondary to a neurologic lesion, particularly in the right frontal or occipital regions. A 40-year-old woman with multiple sclerosis underwent SPECT during and after an episode of CD. Analysis during delusion showed an uptake defect in the right parietal cortex with an 11% index of asymmetry (normal: < 4%). Post-delusion SPECT showed decreased bifrontal and biparietal cortical uptake indices but a normal index of asymmetry. Functional brain imaging may provide clues to the psychopathology of CD.

ISSN:0254-4962    

DOI:10.1159/000284871

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

Dangerousness in the delusional misidentification syndromes is studied by reviewing a sample of 82 cases defined by either verbal threats or physical violence caused by a misidentification delusion. Eighty cases were obtained from a review of the anglophone psychiatric literature in which the patients exhibited some degree of dangerousness, to which we added 2 previously unreported cases.

ISSN:0254-4962    

DOI:10.1159/000284872

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

A review of new cases of delusional misidentification reported between 1986 and 1992 suggests that the delusion of inanimate doubles is a variant of the Capgras phenomenon in approximately 10% of cases. It is argued that this variant makes current psychological theories of misidentification untenable.

ISSN:0254-4962    

DOI:10.1159/000284873

出版商:S. Karger AG    

年代:1994

数据来源: Karger

摘要:

We explore the relation between the Capgras delusion (the belief that your relatives have been replaced by impostors) and the Cotard delusion (the delusional belief that you have died). At first sight, these delusions would seem to have little to do with each other, except that they both involve bizarre claims about existence (for self or others). On closer examination, however, there are other parallels. Here, we summarise similarities in associated impairments of face perception, and argue that both delusions reflect an interaction of impairments at two levels. One set of contributory factors involves perceptual impairment, or anomalous perceptual experience. The other factors lead to an incorrect interpretation of this, for which we offer an explanation in terms of attribution theory. Although the Capgras and Cotard delusions are phenomenally distinct, they may therefore represent attempts to make sense of fundamentally similar experiences.

ISSN:0254-4962    

DOI:10.1159/000284874

出版商:S. Karger AG    

年代:1994

数据来源: Karger