Capgras Syndrome and Other Delusional Misidentification Syndromes

Abstract

The delusional misidentification syndromes (DMS) are a group of disorders, characterized by patients mistaking the identity of people they know, although they recognize them physically. The term DMS is an umbrella term which may cover disorders whose definition extends to objects other than people, such as animals, places, or familiar material objects. The most common and best known DMS is Capgras syndrome. In this disorder, the misidentification leads to the delusional conviction that a close friend or relative has been replaced by an identical - or almost identical - "double," whose original has disappeared. This double is an imposter without name or identity. Most often considered as a persecutor, the double may be subjected to aggression, which may be very violent. Neuropsychological hypotheses based on cerebral dysfunctions are now commonly considered to be at the origin of the disorder. They have been elaborated from achievements in the neurosciences, particularly the facial recognition models. In return, knowledge about the normal cognitive processes involved in recognition and familiarity has benefited from the work that cognitive neuropsychiatry has invested in these disorders. The DMS are observed in various contexts of morbidity: primary psychiatric diagnosis, or secondary to various organic disorders, particularly in neurodegenerative disease; they are rarely met in isolated form. Most often, they develop in line with the associated pathology. In the absence of consensual clinical description, the epidemiology of DMS is uncertain; they may be more frequent than previously supposed. There is no specific treatment for these disorders; neuroleptics are generally used in association with treatment of the concomitant disorder. The frequent association of DMS with organic disorders which may be curable and the particularly dangerous profile of these patients are factors that underline the need for better screening.

Prevalence and Clinical Implications of the Mirror and TV Signs in Advanced Alzheimer’s Disease and Dementia with Lewy Bodies

“…The inclusion criteria for DLB was as follows: (1) patients fulfilled the fourth consensus diagnostic criteria for probable DLB [8], (2) with no or mild ischemic changes on head CT or MRI, and (3) their Mini-Mental State Examination (MMSE) score lay between 0 and 19. The inclusion criteria of AD was as follows: (1) patients fulfilled the clinical diagnostic criteria for probable AD dementia according to the NIA-AA recommendation [16], (2) with no or mild ischemic changes on head CT or MRI, (3) their MMSE score lay between 0 and 19, and (4) without recurrent visual hallucinations. According to these criteria, we selected 200 probable AD dementia and 200 probable DLB subjects from the consecutive patients who were admitted between June 2015 and October 2018.…”

“…Delusional misidentification, which is a false belief about the identity of a person, place, or object, is one major category among BPSDs [1]. A representative symptom is Capgras syndrome, in which a patient believes that a familiar person, such as the spouse, has been replaced by an imposter [2,3]. There is considerable variability in the classification of actual symptoms into the subcategories of delusional misidentification syndromes (DMSs) in previous publications [1,[4][5][6][7].…”

Wahnhafte Missidentifikation und gewalttätiges Verhalten – Risikoabschätzung und Management

“…Trotz hoch dosierter antipsychotischer Pharmakotherapie (Olanzapin 30 mg/d, Levomepromazin [10] an. Da WM bei einer Vielzahl psychischer und organisch bedingter Störungen auftritt [7,11], sollte nicht von einer eigenständigen Krankheitsentität, sondern einem unspezifischen psychopathologischen Symptom bzw. Phänomen ausgegangen werden [12].…”

“…Dabei blieb die affektive Antwort auf die vertraute Stimme eines Angehörigen unbeeinträchtigt. Bei einem Teil der publizierten Fälle mit WM konnten, überwiegend rechtshemisphärische, Läsionen im Bereich des Temporal-und Frontallappens gefunden werden [7]. Auch können fokale Schädigungen in diesen Regionen WM nach sich ziehen.…”

“…Einigkeit besteht in der Literatur dahingegen, dass sich Gewalt im Rahmen von WM üblicherweise gegen wahnhaft verkannte "betrügerische Doppelgänger" richtet [7] und häufig im familiären Rahmen oder gegen enge Bezugspersonen auftritt [4]. Bei 2 der hier geschilderten Kasuistiken (Kasuistik 1 und 3) sind die Opfer der Gewalt aber, entgegen den überwiegenden bisherigen Fallschilderungen, weder Familienangehörige noch vertraute Bezugspersonen, sondern den Patienten erst kurz bekannte Mitarbeiter psychiatrischer Einrichtungen.…”