HASlice and Paul dwell a cheerful retirement in a stone home in a small city in Brittany, sharing their free time between portray, touring, and their grandchildren. One spring morning, Paul notices that his spouse is behaving surprisingly: she observes him suspiciously for a couple of minutes, out of the nook of her eye, silent, then resumes her actions as if nothing had occurred.
The following week, as he entered the kitchen to organize breakfast, his spouse set free a shrill cry when she noticed him, grabbed a kitchen knife and questioned him about his identification: “Who are you? ? What are you doing right here ? Paul, assist! We went dwelling, name the police! » earlier than collapsing on the stone ground. Urgently transferred to the hospital, she explains to the medical doctors {that a} stranger resembling her husband entered the home and spoke to her as in the event that they knew one another. She reviews that she has already seen this unusual look-alike of her husband within the earlier weeks, and that she suspects that he might have damaged into their dwelling a number of occasions.
Capgras syndrome or the phantasm of lookalikes
Capgras syndrome, or delusion of lookalikes, is a uncommon however fascinating neuropsychiatric dysfunction characterised by the delusional perception that family members have been changed by impostors: the affected person then has the horrible impression that strangers are his dwelling, share his life, or converse to him with familiarity. In rarer types of the dysfunction, some sufferers can also have the impression that one object or place has been changed by one other: rooms in the home or gadgets within the wardrobe appear unfamiliar, as if he had by no means lived there or worn these garments.
This identification dysfunction was named in 1929 by the psychiatrist Joseph Lévy-Valensi in homage to the work of the French psychiatrist Joseph Capgras. The latter had revealed in 1923 together with his intern Jean Reboul-Lachaux the medical case of a 53-year-old affected person claiming that her family members had been changed by lookalikes (The phantasm of lookalikes in a persistent systematized delirium). Although uncommon within the normal inhabitants (lower than 0.12%), this type of agnosia (lack of ability to acknowledge one thing within the absence of sensory deficits) is extra frequent in sufferers affected by psychiatric issues (1.3%). and significantly amongst ladies.
A sense of strangeness when contacting family members
The medical presentation of the syndrome is variable. In essentially the most traditional kind, sufferers handle to appropriately acknowledge the faces of their family members, however they’re however satisfied that they’re impostors or doubles: they’re seized by a sense of strangeness attributable to the impression of recognizing the options of these near them, whereas having the sensation that these usually are not actually the folks they know. This is a vital distinction from prosopagnosia (from the Greek prososface), by which sufferers are unable to acknowledge acquainted faces, and have the impression of continually encountering new folks.
At the interface between neurology and psychiatry, Capgras syndrome is commonly related to traumatic mind accidents, strokes, or neurodegenerative illnesses resembling Lewy physique illness or Alzheimer's illness. It can also be present in sure psychiatric issues resembling schizophrenia, and it could actually hardly ever happen throughout very extreme depressive episodes. The neurobiological mechanisms concerned usually are not absolutely understood, however a number of research recommend dysfunctions in neural pathways associated to facial recognition and emotion processing.
A dissociation between bodily notion and emotional state
Indeed, after we meet somebody acquainted, after we observe the options of their face, our mind makes the hyperlink between this morphological info and our episodic reminiscence (reminiscence of moments skilled), bringing collectively all of the reminiscences linked to this particular person . There is thus an emotional hyperlink contributing to the sensation of familiarity felt after we understand the face of a beloved one. In Capgras syndrome, this connection between bodily look and emotional state could also be damaged, inflicting sensory discomfort. In our medical case, the affected person Alice is seized with panic when she sees her husband enter the kitchen: she acknowledges his bodily look however however has the feeling of being confronted with a whole stranger.
A examine revealed in 2017 within the journal Brain by neuroscientists from Beth Israel Deaconess Medical Center (BIDMC) helps this analysis speculation: from 17 medical circumstances, the researchers produced a mind atlas of the lesions related to the dysfunction and a exact mapping of the networks linked to those injured areas. The areas of the mind with lesions have been usually related to the left retrosplenial cortex (Brodmann space 30) and the fitting frontal cortex, two mind areas concerned in face familiarity and perception era.
These outcomes are in line with a speculation suggesting a so-called two-factor course of to clarify the looks of Capgras delusion: first, a disruption within the mind's processing of data crucial for recognition of the familiarity of facial options, inducing the sensation strangeness throughout contact with family members; second, a disruption of perception formation mechanisms, favoring the emergence of delusional perception.
In this murky house between actuality and phantasm, the idea that the beloved one is actually a double makes it doable to clarify the strangeness felt of their presence, serving to to scale back uncertainty.
In this new sequence, psychiatrists Hugo Bottemanne and Lucie Joly* introduce us to those uncommon issues which strike, usually in secret, each the nameless and the beloved one, the mum or dad, the buddy… Through an interesting story and delicate, the 2 medical doctors decipher the obscure and sometimes worrying paths of psychological sickness.
*The medical historical past reported is fictitious however based mostly on actual info which have been assembled with out the potential of particular person identification.
https://www.lepoint.fr/sante/secrets-de-psychiatres-le-syndrome-de-capgras-un-monde-de-sosies-imaginaires-19-04-2024-2558135_40.php