Prevalence of Capgras syndrome in Alzheimer's patients: A systematic review and meta-analysis / Prevalência da síndrome de capgras em pacientes com doença de alzheimer: uma revisão sistemática e metanálise

ABSTRACT The association between Capgras syndrome and Alzheimer's disease has been reported in several studies, but its prevalence varies considerably in the literature, making it difficult to measure and manage this condition. Objective: This study aims to estimate the prevalence of Capgras syndrome in patients with Alzheimer's disease through a systematic review, and to review etiological and pathophysiological aspects related to the syndrome. Methods: A systematic review was conducted using the Medline, ISI, Cochrane, Scielo, Lilacs, and Embase databases. Two independent researchers carried out study selection, data extraction, and qualitative analysis by strictly following the same methodology. Disagreements were resolved by consensus. The meta-analysis was performed using the random effect model. Results: 40 studies were identified, 8 of which were included in the present review. Overall, a total of 1,977 patients with Alzheimer's disease were analyzed, and the prevalence of Capgras syndrome in this group was 6% (CI: 95% I² 54% 4.0-8.0). Conclusion: The study found a significant prevalence of Capgras syndrome in patients with Alzheimer's disease. These findings point to the need for more studies on the topic to improve the management of these patients.

RESUMO A associação da síndrome de Capgras com a doença de Alzheimer é relatada em diversos estudos, porém a sua prevalência varia consideravelmente entre bibliografias, dificultando a real mensuração e manejo desta patologia. Objetivo: O objetivo deste estudo foi estimar, através de uma revisão sistemática, a prevalência da síndrome de Capgras em pacientes com a doença de Alzheimer, bem como revisar os aspectos etiológicos e fisiopatológicos relacionados à síndrome. Métodos: Uma revisão sistemática foi realizada utilizando-se as seguintes bases de dados: Medline, ISI, Cochrane, Scielo, Lilacs e Embase. A seleção dos estudos, extração de dados e análise qualitativa foi feita por dois pesquisadores de forma independente e seguindo rigorosamente a mesma metodologia, sendo as discordâncias resolvidas por consenso. A metanálise foi calculada utilizando-se modelo de efeito randômico. Resultados: Foram recuperados 40 estudos, dos quais 8 foram incluídos na presente revisão. Considerando todos os estudos incluídos, 1977 pacientes com doença de Alzheimer foram analisados, sendo encontrada a prevalência da síndrome de Capgras dentre esses pacientes de 6% (IC: 95% I² 54% 4,0-8,0). Conclusão: A presente revisão encontrou uma prevalência significativa da síndrome de Capgras nos pacientes com doença de Alzheimer. Tal achado implica na necessidade de mais estudos visando melhorar o manejo desses pacientes.

Síndrome de Capgras: una revisión breve / Capgras syndrome: a brief review

Los síndromes de falsa identificación, grupo de patologías neuropsiquiátricas, con las delusiones de falso reconocimiento como denominador común, incluyen, entre otros, al Síndrome de Capgras, caracterizado por la firme creencia, por parte del paciente, de que una persona cercana a él/ella, generalmente un familiar, ha sido sustituida por un doble exacto o impostor , describiendo la similitud física entre ambos; en pocos casos, tal creencia se extiende a animales domésticos e incluso a objetos inanimados. Un alto porcentaje de casos se asocia a un trastorno orgánico cerebral de base, especialmente demencias neurodegenerativas, pero también puede ocurrir en enfermedades psiquiátricas primarias, tales como esquizofrenia y trastornos esquizoafectivos o afectivos. La exploración neurobiológica plantea diferentes hipótesis explicativas del síndrome, entre ellas los modelos de desconexión visuoanatómico de Ellis y Young, de lateralización de Gainotti y de distribución de redes neuronales de Gobbini y Haxby. El falso reconocimiento puede dar lugar a conductas violentas del paciente contra las personas implicadas como supuestos dobles , especialmente en casos de pacientes varones, con enfermedad psiquiátrica de fondo (i.e., esquizofrenia paranoide), con antecedentes de consumo de sustancias psicoactivas o presencia concomitante de alucinaciones auditivas imperativas. No existe tratamiento específico para el Síndrome de Capgras, pero ciertamente el cuadro psiquiátrico subyacente debe ser manejado con fármacos antipsicóticos e incluso terapia electroconvulsiva.

The false identification syndromes, a group of neuropsychiatric pathologies with delusions of false recognition as their common denominator, include among others, the Capgras Syndrome, characterized by the patient s firm belief that a person close to him/her, usually a relative, has been replaced by an exact double or impostor , describing the physical similarity between both; in a few cases, such belief encompasses domestic animals or inanimate objects. A large percentage of cases are associated with a basic organic disorder, especially neurodegenerative dementias, but it can also occur in a basic psychiatric illness such as paranoid schizophrenia, schizoaffective or affective disorders. Among the neurobiological explanations of the Capgras Syndrome, different models have been described: visuo- anatomic disconnection by Ellis and Young, lateralization by Gainotti, neuronal networks distribution by Gobbini and Haxby. The false recognition can lead to violence against the people involved, especially by male patients with an underlying psychiatric illness (i.e., paranoid schizophrenia), a history of psychoactive substance use or the presence of imperative auditory hallucinations. There is no specific treatment for Capgras Syndrome but, certainly, management of the underlying psychiatric condition with antipsychotic drugs and even electroconvulsive therapy, should be initiated.

Síndrome de Capgras: una revision de la literatura / Capgras syndrome: a review of the literature

Los síndromes de falsa identificación delirante (DMS, por su sigla en inglés) son trastornos neuropsiquiátricos poco frecuentes que se caracterizan por tener ideas delirantes respecto a la propia identidad y la de otras personas, animales o lugares conocidos por el paciente. Los principales DMS son el Síndrome de Capgras (SC), el de Fregoli, el de doble subjetivo y el de intermetamorfosis. Se presentan en contexto tanto de enfermedades psiquiátricas como en cuadros orgánicos. Distintos modelos han tratado de encontrar una explicación a los DMS, con aportes tanto desde la psicología como de las neurociencias. Entre las causas están enfermedades neurodegenerativas, cuadros psiquiátricos, alteraciones estructurales, efecto de drogas, y alteraciones metabólicas. El manejo depende de la patología de base y las características clínicas específicas. Esta revisión se centra específicamente en el SC, ya que dentro de los DMS, es el más frecuente y estudiado

Delusional misidentification syndromes (DMS) are rare neuropsychiatric disorders that are characterized by having delirious ideas regarding one's and other people, animals or places identity known by the patient. The main DMS are the Capgras syndrome, the Fregoli syndrome, the subjective double syndrome and the intermetamorphosis syndrome. They appear in context of both psychiatric illnesses and organic disorders. Different models have tried to find an explanation to the DMS, with contributions from both psychology and neurosciences. Among the causes are neurodegenerative diseases, psychiatric symptoms, structural alterations, drug effects, and metabolic alterations. Management depends on the underlying pathology and the specific clinical characteristics. This review focuses specifically on the SC, since within the DMS, it is the most frequent and studied.

Paramnesia reduplicativa: a propósito de un caso asociado a esquizofrenia / Reduplicative paramnesia: a propos of a case associated with schizophrenia

Los síndromes de falsa identificación delusional (SFID) constituyen un cuadro clínico relativamente frecuente en la casuística psiquiátrica aunque la paramnesia reduplicativa (PR) se ha atribuido con más frecuencia a causas de tipo orgánico cerebral. Presentamos el caso de un paciente con diagnóstico de esquizofrenia paranoide, que desarrolló paramnesia reduplicativa afirmando que poseía dos domicilios iguales, uno verdadero y otro falso -copia del primero-, pero en este último no podía respirar porque no disponía de aire. Dentro de una breve revisión de la literatura respectiva, hallamos progresos en la explicación neurobiológica de la PR, sobre todo a partir del fenómeno hallado en pacientes con organicidad cerebral, sin embargo subsisten preguntas que pueden requerir una concepción más abarcativa de este síntoma en cuanto manifestación psicótica de la esquizofrenia.

Delusional misidentification syndromes (DMS) are a relatively common group of disorders in clinical psychiatry, although the symptom known as Reduplicative Paramnesia (RP) has been, in most cases, attributed to organic (brain- related) causes. The case of a patient with diagnosis of paranoid schizophrenia who developed RP is presented: he reported having two identical homes, one real and one false, the latter a copy of the former, but in which he could not breathe because of lack of air. A brief review of the literature revealed progress in the neurobiological explanation of RP, particularly related to evidences of organic cerebral pathology; nevertheless, a number of questions remain, requiring a more comprehensive conception of this symptom as a psychotic manifestation of schizophrenia.

Capgras syndrome associated with limbic encephalitis in a patient with diffuse large B-cell lymphoma / Síndrome de Capgras associada a Encefalite Límbica em um Paciente com Linfoma Difuso de Grandes Células B

We report the case of a patient with insidious onset and slowly progressive cognitive impairment, behavioral symptoms, temporal lobe seizures and delusional thoughts typical of delusional misidentification syndromes. Clinical presentation along with extensive diagnostic work-up revealed limbic encephalitis secondary to diffuse large B-cell lymphoma. The patient underwent immunotherapy with high-dose corticosteroid but no significant improvement was observed. No specific treatment for lymphoma was performed because the patient died of septic shock following a nosocomial respiratory infection. Delusional misidentification syndromes are an unusual and unique form of cognitive impairment in which a patient consistently misidentifies persons, places, objects, or events. Capgras syndrome is the most common subtype of this disorder, being defined by the recurrent and transient belief that someone close has been substituted by an imposter. These entities are generally associated with neurodegenerative diseases and psychiatric disturbances. Rare reports of associations between misidentification syndromes and autoimmune diseases such as multiple sclerosis have been published, but no papers address a correlation with limbic encephalitis or lymphoma.

Nós relatamos o caso de um paciente com início insidioso e lentamente progressivo de declínio cognitivo, sintomas comportamentais, crises convulsivas do lobo temporal e pensamentos delirantes típicos dos delírios monotemáticos de identificação. A apresentação clínica associada aos exames complementares levaram ao diagnóstico de encefalite límbica relacionada a linfoma difuso de grandes células B. O paciente foi submetido a imunoterapia com altas doses de corticoide sem melhora clínica. Não foi realizado tratamento específico para o linfoma em função do paciente ter evoluído para óbito por choque séptico secundário a infecção respiratória nosocomial. Os delírios monotemáticos de identificação representam uma forma única e incomum de comprometimento cognitivo nas quais o paciente consistentemente identifica de forma errônea pessoas, lugares, objetos ou eventos. A síndrome de Capgras é o subtipo mais comum dessas desordens, sendo definida como a crença recorrente e transitória que um impostor substituiu uma pessoa familiar. Essas entidades são geralmente relacionadas com doenças neurodegenerativas e distúrbios psiquiátricos. Raros relatos da associação entre os delírios monotemáticos de identificação e doenças autoimunes como esclerose múltipla foram publicados, porém não há artigos abordando a correlação com encefalite límbica ou linfoma.

Capgras syndrome presenting in an adolescent girl in the Caribbean / El síndrome de capgras en una adolescente del Caribe

The case of a 16-year old Jamaican girl who presented to the psychiatric service of a general hospital with features of Capgras syndrome is presented. Her history, treatment, progress and relevant psychodynamic and neurocognitive issues are explored. This is the first known published case of an adolescent with Capgras syndrome from the Caribbean. The case highlights that the syndrome may occur in different cultural contexts and that clinicians should be sensitive to its existence in order to avert under-diagnosis or misdiagnosis.

Se presenta el caso de una joven jamaicana de 16 años que acudió al servicio de psiquiatría de un hospital general con los rasgos del síndrome de Capgras. Se explora su historia, tratamiento, progreso, problemas neurocognitivos y psicodinámicos relevantes. Éste es el primer caso publicado de que se tenga noticias, de una adolescente con el síndrome de Capgras en la región del Caribe. El caso pone de relieve que el síndrome puede ocurrir en diferentes contextos culturales, y que los médicos deben de estar sensibilizados con su existencia a fin de evitar un subdiagnóstico o un diagnóstico erróneo.