DELUSIONAL MISIDENTIFICATION SYNDROME: DISSOCIATION BETWEEN RECOGNITION AND IDENTIFICATION PROCESSES

Delusional misidentification syndrome (DMS) is an umbrella term for syndromes of intermetamorphosis, Fregoli, and Capgras. DMS) is thought to be related to dissociation between recognition and identification processes. DMS was described for the first time in 1932 as a variant of the Capgras syndrome and is currently on the DSM-V list of diseases as an independent disease entity. Patients affected by DMS believed that people around them, most often family, have changed physically (appearance) and mentally (character). Other symptoms include confabulation, derealization or depersonalization. In patients, aggressive behavior is often observed, aimed at alleged doppelgangers resulting from the sense of being cheated and manipulated. With the intermetamorphosis syndrome, for example, schizophrenia, depression, bipolar disorder or other misidentification syndromes (Fregoli's, Capgras) may coexist. There is also a reverse intermetamorphosis, where the object of the changed appearance or character becomes the patient himself. One of its forms may be lycanthropy. The etiology of the intermetamorphosis has not been fully understood, one of the reasons may be brain damage and changes in the parietal and/or temporal lobes of the right hemisphere. It may then damage long neuronal connections to the frontal areas of the brain, disturbances of working memory (WM) accountable for the keep and online management of data, so that it is available for further processing, and the patient's will be uncritical. The basic method of diagnosis of this delusion is a medical interview with the patient. Other diagnostic methods include computed tomography, magnetic resonance imaging, EEG and ERPs. Experimental methods include searching for the neuromarker of DMS. Currently, there are no treatment guidelines of this delusional disorder, and pharmacotherapy experimental, but the drugs from the group of neuroleptics and lithium seem effective. Some hope for the treatment is created by neurotherapy, but it is also experimental.

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Psychiatric, neurological and medical aspects of misidentification syndromes: a review of 260 cases

Psychological Medicine ◽

10.1017/s0033291700029895 ◽

1991 ◽

Vol 21 (4) ◽

pp. 905-910 ◽

Cited By ~ 114

Author(s):

Hans Förstl ◽

Osvaldo P. Almeida ◽

Adrian M. Owen ◽

Alistair Burns ◽

Robert Howard

Keyword(s):

Right Hemisphere ◽

Neurological Diseases ◽

Case Reports ◽

Neuropsychological Testing ◽

Functional Psychosis ◽

Paranoid Type ◽

The Right ◽

Misidentification Syndromes ◽

Mistaken Identification ◽

Reduplicative Paramnesia

SYNOPSISTwo hundred and sixty case reports of misidentification syndromes were evaluated. One hundred and seventy-four patients had a Capgras syndrome misidentifying other persons, 18 a Fregoli syndrome, 11 intermetamorphosis, 17 reduplicative paramnesia and the rest had other forms or combinations of mistaken identification. Schizophrenia (127 cases), mostly of paranoid type, affective disorder (29), and organic mental syndromes including dementia (46) were the most common diagnoses in patients who misidentified others or themselves. The patients with reduplicative paramnesia more frequently suffered from head trauma or cerebral infarction and showed more features of right hemisphere lesions on neuropsychological testing or CT scan than the patients with other misidentification syndromes. Forty-one case-reports implicated underlying medical conditions. Forty-six of the patients were reported to show violent behavioaur.The misidentification of persons can be a manifestation of any organic or functional psychosis, but the misidentification of place is frequently associated with neurological diseases, predominantly of the right hemisphere. Misidentification syndromes show a great degree of overlap and do not represent distinctive syndromes nor can they be regarded as an expression of a particular disorder. These patients deserve special diagnostic and therapeutic attention because of the possible underlying disorders and their potentially dangerous behavioura.

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Lithium Intoxication Presenting as a Mixed Misidentification Syndrome

Behavioural Neurology ◽

10.1155/1992/489282 ◽

1992 ◽

Vol 5 (1) ◽

pp. 19-22 ◽

Cited By ~ 6

Author(s):

S. G. Potts

Keyword(s):

Right Hemisphere ◽

Cerebral Atrophy ◽

Ct Scanning ◽

Lithium Intoxication ◽

Capgras Syndrome ◽

The Right ◽

Misidentification Syndromes

A case is reported of lithium intoxication presenting with a mixed misidentification syndrome including features of Capgras syndrome. CT scanning showed cerebral atrophy, greater on the right, consistent with earlier evidence, suggesting that misidentification syndromes are more common with right hemisphere lesions.

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Depressed Subjects Have Decreased rCBF Activation During Facial Emotion Recognition

CNS Spectrums ◽

10.1017/s1092852900011081 ◽

1997 ◽

Vol 2 (10) ◽

pp. 45-55 ◽

Cited By ~ 3

Author(s):

Mark S. George ◽

Terence A. Ketter ◽

Priti I. Parekh ◽

Debra S. Gill ◽

Lauren Marangell ◽

...

Keyword(s):

Emotion Recognition ◽

Right Hemisphere ◽

Brain Regions ◽

Facial Emotion Recognition ◽

Facial Emotion ◽

Temporal Lobes ◽

Facial Identity ◽

Positron Emission ◽

The Right ◽

Right Hemisphere Brain Damage

AbstractDepressed subjects have deficits in facialemotion recognition that resemble the deficits found in persons with focal right hemisphere brain damage. To locate the brain regions responsible for this problem, the authors imaged regional cerebral blood flow (rCBF) with H2O15 positron emission tomography in 10 mood-disordered patients, as well as in 10 age- and sex-matched healthy comparison subjects, while the subjects matched photographs for facial emotion or, as a control, facial identity. While matching faces for emotion, mood-disordered subjects had decreased rCBF activation bilaterally in their temporal lobes, as well as in the right insula, compared with healthy comparison subjects. Abnormal function of limbic and paraiimbic regions may partially explain the facial emotion-recognition deficits previously noted in depressed subjects.

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Why Are the Right and Left Hemisphere Conceptual Representations Different?

Behavioural Neurology ◽

10.1155/2014/603134 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 20

Author(s):

Guido Gainotti

Keyword(s):

Left Hemisphere ◽

Conceptual Knowledge ◽

Right Hemisphere ◽

Semantic Knowledge ◽

Temporal Lobes ◽

Conceptual Representations ◽

Motor Information ◽

Advanced Stages ◽

The Right ◽

Joint Disruption

The present survey develops a previous position paper, in which I suggested that the multimodal semantic impairment observed in advanced stages of semantic dementia is due to the joint disruption of pictorial and verbal representations, subtended by the right and left anterior temporal lobes, rather than to the loss of a unitary, amodal semantic system. The main goals of the present review are (a) to survey a larger set of data, in order to confirm the differences in conceptual representations at the level of the right and left hemispheres, (b) to examine if language-mediated information plays a greater role in left hemisphere semantic knowledge than sensory-motor information in right hemisphere conceptual knowledge, and (c) to discuss the models that could explain both the differences in conceptual representations at the hemispheric level and the prevalence of the left hemisphere language-mediated semantic knowledge over the right hemisphere perceptually based conceptual representations.

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Spatial distribution and hemispheric asymmetry of electrically evoked experiential phenomena in the human brain

Journal of Neurosurgery ◽

10.3171/2019.3.jns183429 ◽

2020 ◽

Vol 133 (1) ◽

pp. 54-62 ◽

Cited By ~ 1

Author(s):

Michal M. Andelman-Gur ◽

Tomer Gazit ◽

Fani Andelman ◽

Svetlana Kipervasser ◽

Uri Kramer ◽

...

Keyword(s):

Neural Networks ◽

Left Hemisphere ◽

Right Hemisphere ◽

Functional Organization ◽

Focal Epilepsy ◽

Drug Resistant ◽

Visual Hallucinations ◽

Presurgical Evaluation ◽

Temporal Lobes ◽

The Right

OBJECTIVEExperiential phenomena (EP), such as illusions and complex hallucinations, are vivid experiences created in one’s mind. They can occur spontaneously as epileptic auras or can be elicited by electrical brain stimulation (EBS) in patients undergoing presurgical evaluation for drug-resistant epilepsy. Previous work suggests that EP arise from activation of different nodes within interconnected neural networks mainly in the temporal lobes. Yet, the anatomical extent of these neural networks has not been described and the question of lateralization of EP has not been fully addressed. To this end, an extended number of brain regions in which electrical stimulation elicited EP were studied to test whether there is a lateralization propensity to EP phenomena.METHODSA total of 19 drug-resistant focal epilepsy patients who underwent EBS as part of invasive presurgical evaluation and who experienced EP during the stimulation were included. Spatial dispersion of visual and auditory illusions and complex hallucinations in each hemisphere was determined by calculation of Euclidean distances between electrodes and their centroid in common space, based on (x, y, z) Cartesian coordinates of electrode locations.RESULTSIn total, 5857 stimulation epochs were analyzed; 917 stimulations elicited responses, out of which 130 elicited EP. Complex visual hallucinations were found to be widely dispersed in the right hemisphere, while they were tightly clustered in the occipital lobe of the left hemisphere. Visual illusions were elicited mostly in the occipital lobes bilaterally. Auditory illusions and hallucinations were evoked symmetrically in the temporal lobes.CONCLUSIONSThese findings suggest that complex visual hallucinations arise from wider spread in the right compared to the left hemisphere, possibly mirroring the asymmetry in the white matter organization of the two hemispheres. These results offer some insights into lateralized differences in functional organization and connectivity that may be important for functional mapping and planning of surgical resections in patients with epilepsy.

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Visual Hypo and Hypergnosia as Exemplars of Poles of Psychic Tonus in the Occipital Lobes: Multiple Case Analyses

Behavioural Neurology ◽

10.1155/2008/139436 ◽

2008 ◽

Vol 19 (4) ◽

pp. 153-168

Author(s):

Claude M. J. Braun ◽

Anik Guimond

Keyword(s):

Visual Imagery ◽

Visual Hallucination ◽

Right Hemisphere ◽

Hemispheric Specialization ◽

Unilateral Lesion ◽

Temporal Lobes ◽

Parietal Lobes ◽

Multiple Case ◽

The Right ◽

Occipital Lobes

The “psychic tonus” model or PTM [1] of hemispheric specialization states that the left hemisphere is a psychic and behavioral activator and that the right hemisphere is an inhibitor. The PTM predicts that the tonus of visual representation ought to manifest hemispheric specialization in the occipital lobes. Specifically PTM predicts that pathological positive visual tonus (visual hallucination) ought to be associated more frequently with right occipital lesions. PTM also predicts that pathological negative visual tonus (loss of visual imagery) ought to result more often from left occipital lesions. We reviewed 78 cases of post lesion hallucination and 12 cases of post lesion loss of evocation of images, all following a unilateral lesion. Analyses of these relevant previously published cases support the predictions. In accordance with previously published demonstrations of hemispheric specialization for auditory tonus in the temporal lobes and for somesthetic tonus in the parietal lobes, the present findings extend the psychic tonus model of hemispheric specialization to vision in the occipital lobes.

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Investigation of the Effect of Mode and Tempo on Emotional Responses to Music Using EEG Power Asymmetry

Journal of Psychophysiology ◽

10.1027/0269-8803/a000099 ◽

2013 ◽

Vol 27 (3) ◽

pp. 142-148 ◽

Cited By ~ 11

Author(s):

Konstantinos Trochidis ◽

Emmanuel Bigand

Keyword(s):

Left Hemisphere ◽

Right Hemisphere ◽

Emotional Responses ◽

Interactive Effects ◽

Eeg Activity ◽

Musical Excerpt ◽

Major Mode ◽

Musical Modes ◽

Slow Tempo ◽

The Right

The combined interactions of mode and tempo on emotional responses to music were investigated using both self-reports and electroencephalogram (EEG) activity. A musical excerpt was performed in three different modes and tempi. Participants rated the emotional content of the resulting nine stimuli and their EEG activity was recorded. Musical modes influence the valence of emotion with major mode being evaluated happier and more serene, than minor and locrian modes. In EEG frontal activity, major mode was associated with an increased alpha activation in the left hemisphere compared to minor and locrian modes, which, in turn, induced increased activation in the right hemisphere. The tempo modulates the arousal value of emotion with faster tempi associated with stronger feeling of happiness and anger and this effect is associated in EEG with an increase of frontal activation in the left hemisphere. By contrast, slow tempo induced decreased frontal activation in the left hemisphere. Some interactive effects were found between mode and tempo: An increase of tempo modulated the emotion differently depending on the mode of the piece.

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Right-Hemisphere Specialization for Contour Grouping

Experimental Psychology (formerly Zeitschrift für Experimentelle Psychologie) ◽

10.1027/1618-3169/a000252 ◽

2014 ◽

Vol 61 (5) ◽

pp. 331-339 ◽

Cited By ~ 1

Author(s):

Gregor Volberg

Keyword(s):

Right Hemisphere ◽

Contour Detection ◽

Global Processing ◽

Detection Accuracy ◽

Frequency Spectra ◽

Visual Hemifield ◽

Spatial Frequencies ◽

A Chain ◽

The Right ◽

Hemisphere Specialization

Previous studies often revealed a right-hemisphere specialization for processing the global level of compound visual stimuli. Here we explore whether a similar specialization exists for the detection of intersected contours defined by a chain of local elements. Subjects were presented with arrays of randomly oriented Gabor patches that could contain a global path of collinearly arranged elements in the left or in the right visual hemifield. As expected, the detection accuracy was higher for contours presented to the left visual field/right hemisphere. This difference was absent in two control conditions where the smoothness of the contour was decreased. The results demonstrate that the contour detection, often considered to be driven by lateral coactivation in primary visual cortex, relies on higher-level visual representations that differ between the hemispheres. Furthermore, because contour and non-contour stimuli had the same spatial frequency spectra, the results challenge the view that the right-hemisphere advantage in global processing depends on a specialization for processing low spatial frequencies.

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