Prevalence and correlates of Capgras syndrome in Alzheimer's disease

Capgras Syndrome as the Core Manifestation of Early-Onset Alzheimer’s Disease

Capgras syndrome (CS) was usually considered a symptom of a functional disorder in the young, most commonly schizophrenia, or an organic disorder in the elderly. The occurrence of CS among early-onset Alzheimer’s disease (EOAD) is extremely rare. We describe a case in which the unrecognition of CS as part of EOAD resulted in a wrong psychiatric diagnosis and inappropriate treatment. This paper aims to acknowledge CS as an early or core manifestation and highlight EOAD as a differential diagnosis of mental disorders in young people, even without a remarkable family history.

Psychosis

PURPOSE OF REVIEW

Psychosis can manifest in primary psychotic disorders, neurologic diseases, and medical conditions. This article reviews the definition of psychotic symptoms and the evaluation and management of psychosis in primary psychiatric and neurologic disorders frequently seen in neurologic practice.

RECENT FINDINGS

Emerging evidence supports significant connections between psychosis and structural and functional brain changes in both primary psychotic and neurologic disorders. In addition to antidopaminergic activity, the mechanism of new-generation antipsychotics shifts to act on serotonin receptors, which potentially contributes to their benefits in the treatment of negative symptoms of psychosis and a lesser frequency of extrapyramidal side effects compared with typical antipsychotics. This is also helpful in the treatment of psychosis in patients who have neurodegenerative diseases and are vulnerable to developing extrapyramidal side effects from typical antipsychotics.

SUMMARY

Even with significant overlap, management of psychosis in primary psychotic disorders differs from the approach of psychosis in neurologic diseases. This article helps clinicians learn how to practically evaluate psychosis from both psychiatric and neurologic perspectives.

Evolution of Capgras syndrome in neurodegenerative disease: the multiplication phenomenon

Capgras syndrome (CS) is a delusional misidentification syndrome that is encountered in various pathologies. Here, we report the case of an 83-year-old woman affected by dementia with Lewy bodies who presented a CS during the disease. The neuropsychological assessment showed executive and face processing deficits. In this case, CS was characterized, in the beginning, by the duplication of a relative and then by its multiplication. To our knowledge, the description of the evolution of a CS in the course of a neurodegenerative disease is rare and we discuss this multiplication phenomenon in light of existing models of delusions.

Capgras Syndrome in the Young: Schizophrenia or Alzheimer Disease?

This is a case report of an atypical presentation of early onset Alzheimer disease (EOAD) in a young patient with Capgras syndrome and cognitive impairment. The concurrent onset of psychiatric and cognitive symptoms prompted a detailed evaluation for a neurodegenerative disease. A 50-year-old male lawyer presented with low mood, apathy, delusions, and auditory hallucinations over 18 months. He considered his wife as an imposter and would require her text message to confirm her identity. He became more forgetful and had to give up his law practice. His neuropsychological assessment was impaired in all domains. Genetic testing revealed homozygosity for APOEe4 alleles. His magnetic resonance imaging showed predominant parietal and medial temporal atrophy, [18F]Fluorodeoxyglucose positron emission tomography showed frontal, parietal and posterior temporal hypometabolism and [18F]Flutemetamol positron emission tomography was positive for amyloid deposition, leading to the diagnosis of EOAD. This case highlights EOAD as a differential diagnosis in young patients who present with Capgras syndrome.

[Delusional Misidentification Syndrom and Violent Behavior - Risk Assessment and Management]

OBJECTIVE AND METHOD

A case series of three patients with Delusional Misidentification Syndroms (DMS) and violent behavior is presented with respect to the correlation between DMS and violence as well as to the management of such occurrences.

RESULTS AND CONCLUSION

DMS could be one of the reasons for violent behavior of patients with psychiatric disorders. In such case violent behavior is not just restricted to intimates and relatives but also turns on non-familiar caregivers. DMS could be a risk factor for violent behavior and should therefore be registered with help of a nuanced psychopathological exploration at the time of clinical admission and in course of treatment. Moreover risk assessment tools and safety measures (e. g. medication, monitoring) could be considered for patients with DMS.

Prevalence of Capgras syndrome in Alzheimer's patients: A systematic review and meta-analysis

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.

A Case of Capgras Syndrome With Frontotemporal Dementia

Capgras syndrome (CS), also called imposter syndrome, is a rare psychiatric condition that is characterized by the delusion that a family relative or close friend has been replaced by an identical imposter. Here, we describe a 69-year-old man with CS who presented to the Kemal Arikan Psychiatry Clinic with an ongoing belief that his wife had been replaced by an identical imposter. MRI showed selective anterior left temporal lobe atrophy. Quantitative EEG showed bilateral frontal and temporal slowing. Neuropsychological profiling identified a broad range of deficits in the areas of naming, executive function, and long-term memory. On the basis of these findings, we diagnosed frontotemporal dementia. This case demonstrates that CS can clinically accompany frontotemporal dementia.

In fear of the most loved ones. A comprehensive review on Capgras misidentification phenomenon and case report involving attempted murder under Capgras syndrome in a relapse of a schizophrenia spectrum disorder

The present paper aims to describe a case of a schizophrenia spectrum disorder relapse leading to attempted murder, review literature, and investigate the epidemiological data and expression of violent behavior among Capgras-related incidents. 109 case reports deriving from various scientific areas dating from 1971 to 2017 were evaluated and juxtaposed with an equivalent comparison group of random psychiatry inpatients, who were examined for the same variables. Quantitative and qualitative differences were observed between samples. High level of interpersonal violence was disclosed among Capgras-related incidents, especially towards the main care-givers, with higher propensity among male patients. Homicidal behavior was also expressed in higher levels among male patients experiencing the Capgras delusion. A multidisciplinary approach is vital for the optimal management of these incidents. Further research on the pathophysiology of Capgras delusion with the utilization of functional imaging techniques is of exceptional significance for the understanding of issues of neuroscience.

Association Between Psychosis Phenotype and APOE Genotype on the Clinical Profiles of Alzheimer's Disease

BACKGROUND

Psychosis is a common phenomenon in Alzheimer's disease (AD). The APOE ε4 allele is the strongest genetic risk factor for the development of AD, but its association with psychosis remains unclear.

OBJECTIVE

We investigated the associations between psychosis, subdivided into delusions and hallucinations, as well as APOE ε4 allele on cognitive and functional outcomes. Secondarily, we investigated the associations between APOE ε4, Lewy bodies, and psychosis.

METHODS

Data from the National Alzheimer's Coordinating Center (NACC) were used. Nine hundred patients with a confirmed diagnosis of AD based on the NIA-AA Reagan were included in the analysis. Global cognition was assessed using the Mini-Mental State Exam (MMSE) and functional status was assessed using the Functional Activities Questionnaire (FAQ). Psychosis status was determined using the Neuropsychiatric Inventory Questionnaire (NPI-Q). Factorial design was used to assess the effects of psychosis and APOE ε4, as well as their interaction.

RESULTS

Psychosis and the presence of APOE ε4 were both associated with lower MMSE scores, while only psychosis was associated with higher FAQ scores. Furthermore, patients with hallucinations had lower MMSE and higher FAQ scores than patients with only delusions. There was a significant interaction effect between psychosis and APOE ε4 on MMSE scores, with APOE ε4 negatively affecting patients with hallucinations-only psychosis. APOE ε4 was positively associated with the presence of Lewy body pathology, and both were found to be more prevalent in psychotic patients, with a stronger association with hallucinations.

CONCLUSION

Psychosis in AD was associated with greater cognitive and functional impairments. Patients with hallucinations-with or without delusions-conferred even greater deficits compared to patients with only delusions. The APOE ε4 allele was associated with worse cognition, especially for patients with hallucination-only psychosis. APOE ε4 may mediate cognitive impairment in the hallucinations phenotype through the development of Lewy bodies. Our findings support that subtypes of psychosis should be evaluated separately.

Uncovering Capgras delusion using a large-scale medical records database

BACKGROUND

Capgras delusion is scientifically important but most commonly reported as single case studies. Studies analysing large clinical records databases focus on common disorders but none have investigated rare syndromes.

AIMS

Identify cases of Capgras delusion and associated psychopathology, demographics, cognitive function and neuropathology in light of existing models.

METHOD

Combined computational data extraction and qualitative classification using 250 000 case records from South London and Maudsley Clinical Record Interactive Search (CRIS) database.

RESULTS

We identified 84 individuals and extracted diagnosis-matched comparison groups. Capgras was not 'monothematic' in the majority of cases. Most cases involved misidentified family members or close partners but others were misidentified in 25% of cases, contrary to dual-route face recognition models. Neuroimaging provided no evidence for predominantly right hemisphere damage. Individuals were ethnically diverse with a range of psychosis spectrum diagnoses.

CONCLUSIONS

Capgras is more diverse than current models assume. Identification of rare syndromes complements existing 'big data' approaches in psychiatry.

DECLARATION OF INTERESTS

V.B. is supported by a Wellcome Trust Seed Award in Science (200589/Z/16/Z) and the UCLH NIHR Biomedical Research Centre. S.W. is supported by a Wellcome Trust Strategic Award (WT098455MA). Q.D. has received a grant from King's Health Partners.

COPYRIGHT AND USAGE

© The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

Vascular risk factors and neuropsychiatric symptoms in Alzheimer's disease: the Cache County Study

OBJECTIVE

Knowledge of potentially modifiable risk factors for neuropsychiatric symptoms (NPS) in Alzheimer's disease (AD) is important. This study longitudinally explores modifiable vascular risk factors for NPS in AD.

METHODS

Participants enrolled in the Cache County Study on Memory in Aging with no dementia at baseline were subsequently assessed over three additional waves, and those with incident (new onset) dementia were invited to join the Dementia Progression Study for longitudinal follow-up. A total of 327 participants with incident AD were identified and assessed for the following vascular factors: atrial fibrillation, hypertension, diabetes mellitus, angina, coronary artery bypass surgery, myocardial infarction, cerebrovascular accident, and use of antihypertensive or diabetes medicines. A vascular index (VI) was also calculated. NPS were assessed over time using the Neuropsychiatric Inventory (NPI). Affective and Psychotic symptom clusters were assessed separately. The association between vascular factors and change in NPI total score was analyzed using linear mixed model and in symptom clusters using a random effects model.

RESULTS

No individual vascular risk factors or the VI significantly predicted change in any individual NPS. The use of antihypertensive medications more than four times per week was associated with higher total NPI and Affective cluster scores.

CONCLUSIONS

Use of antihypertensive medication was associated with higher total NPI and Affective cluster scores. The results of this study do not otherwise support vascular risk factors as modifiers of longitudinal change in NPS in AD.

Capgras' syndrome in first-episode psychotic disorders

BACKGROUND

Misidentification phenomena, including the delusion of 'imposters' named after Joseph Capgras, occur in various major psychiatric and neurological disorders but have rarely been studied systematically in broad samples of modern patients. This study investigated the prevalence and correlated clinical factors of Capgras' phenomenon in a broad sample of patient-subjects with first-lifetime episodes of psychotic affective and nonaffective disorders.

METHODS

We evaluated 517 initially hospitalized, first-episode psychotic-disorder patients for the prevalence of Capgras' phenomenon and its association with DSM-IV-TR diagnoses including schizophreniform, brief psychotic, unspecified psychotic, delusional, and schizoaffective disorders, schizophrenia, bipolar-I disorder and major depression with psychotic features, and with characteristics of interest including antecedent psychiatric and neurological morbidity, onset type and presenting psychopathological phenomena, using standard bivariate and multivariate statistical methods.

RESULTS

Capgras' syndrome was identified in 73/517 (14.1%) patients (8.2-50% across diagnoses). Risk was greatest with acute or brief psychotic disorders (schizophreniform psychoses 50%, brief psychoses 34.8%, or unspecified psychoses 23.9%), intermediate in major depression (15%), schizophrenia (11.4%) and delusional disorder (11.1%), and lowest in bipolar-I (10.3%) and schizoaffective disorders (8.2%). Associated were somatosensory, olfactory and tactile hallucinations, Schneiderian (especially delusional perception), and cycloid features including polymorphous psychotic phenomena, rapidly shifting psychomotor and affective symptoms, pananxiety, ecstasy, overconcern with death, and perplexity or confusion, as well as rapid onset, but not sex, age, abuse history, dissociative features, or indications of neurological disorders.

CONCLUSIONS

Capgras' syndrome was prevalent across a broad spectrum of first-episode psychotic disorders, most often in acute psychoses of rapid onset.

Delusional misidentification syndromes and dementia: a border zone between neurology and psychiatry

The delusional misidentification syndromes (DMSs) are psychopathologic phenomena in which a patient consistently misidentifies persons, places, objects, or events. Although often described in relation to psychotic states including schzofrenia, it is, nevertheless, widely considered that these syndromes have an anatomical basis because of their frequent association with organic brain disease; studies have pointed to the presence of identifiable lesions, especially in the right frontal lobe and adjacent regions, in a considerable proportion of patients. The purpose of this article is to examine the phenomenon in people with dementia. We searched the electronic databases for original research and review articles on DMS in patients with dementia using the search terms "Delusional Misidentification Syndrome, Capgras syndrome, Fregoli syndrome, reduplicative paramnesia, and dementia." The DMSs are a frequent problem in dementia. The violence and dangerousness in patients with dementia having these syndromes are well documented, and forensic aspects are highlighted. Pathogenetic viewpoint and management are considered.

Origins of delusions in Alzheimer's disease

Research over the past two decades supports a shared aetiology for delusions in Alzheimer's disease (AD) and schizophrenia. Functional networks involved in salience attribution and belief evaluation have been implicated in the two conditions, and striatal D2/3 receptors are increased to a comparable extent. Executive/frontal deficits are common to both disorders and predict emergent symptoms. Putative risk genes for schizophrenia, which may modify the AD process, have been more strongly implicated in delusions than those directly linked with late-onset AD. Phenotypic correlates of delusions in AD may be dependent upon delusional subtype. Persecutory delusions occur early in the disease and are associated with neurochemical and neuropathological changes in frontostriatal circuits. In contrast, misidentification delusions are associated with greater global cognitive deficits and advanced limbic pathology. It is unclear whether the two subtypes are phenomenologically and biologically distinct or are part of a continuum, in which misidentification delusions manifest increasingly as the pathological process extends. This has treatment implications, particularly if they are found to have discrete chemical and/or pathological markers.

The prevalence of misidentification syndromes in neurodegenerative diseases

Although misidentification syndromes (MISs) have been often described in Alzheimer disease (AD), the prevalence of these phenomena in different neurodegenerative diseases has not been systematically studied. Three hundred ninety-two individuals with probable AD, 119 patients with the behavioral variety of frontotemporal dementia (FTD-bv), 101 patients with primary progressive aphasia, 24 subjects with semantic dementia, 18 subjects with corticobasal degeneration, 8 patients with progressive supranuclear palsy, 36 individuals with probable Lewy body dementia (DLB), and 26 subjects with Parkinson disease (PD) were the participants of this study. On the basis of a semistructured interview with both patients and their reliable caregivers, MIS was identified in 15.8% of cases with AD, 16.6% of patients with DLB, and in 8.3% of individuals with semantic dementia. The most frequent form of MIS was Capgras delusions, often accompanied by reduplication of place, phantom border phenomenon, or both. Although MIS typically appears in later stages of the disease, it can also occur surprisingly early in patients with AD. None of the patients with FTD-bv, primary progressive aphasia, corticobasal degeneration/supranuclear palsy, or PD developed MIS. Thus, our findings suggest that MISs are characteristic of AD and DLB, and tend to exclude FTD/Pick complex and PD.

A prospective study of delusional misidentification syndromes in Parkinson's disease with dementia

Delusional misidentification syndromes (DMS) are a group of neuropsychiatric disorders due to disturbances in familiarity. DMS in organic diseases have been related to deficits in executive, memory, and visuospatial function. DMS are frequently reported in dementia with Lewy bodies (DLB). The presence of DMS in Parkinson's disease with dementia (PDD), which shares similar clinical and neuropsychological features with DLB, has not been studied. We describe the frequency and clinical features of DMS in a cohort of PDD patients, and we compare the neuropsychological profile between PDD patients with and without DMS. Prospective study of 30 PDD patients recruited from an outpatient setting, who received a structured behavioral interview assessing DMS and hallucinations, and a neuropsychological battery assessing executive function, memory, language, and visuospatial abilities. DMS were found in 16.7% of PDD patients. All DMS subjects also exhibited hallucinations that were significantly more severe than in PDD without DMS. DMS were responsive to neuroleptic drugs. PDD subjects with DMS presented a different neuropsychological profile than PDD subjects without DMS, with more severe memory and language deficits, but similar levels of executive and visuospatial impairment. DMS is a neuropsychiatric feature associated with PDD. Greater impairment in language and memory in PDD with DMS suggests a prominent role of the temporal cortex in the genesis of DMS in PDD.

Frontotemporal dementia to Alzheimer's disease

Behavioral manifestations may dominate the clinical picture of the frontal variant of frontotemporal dementia (fv-FTD) for a long time before the appearance of true cognitive deficits. On the other hand, a deficit in the episodic memory domain represents the main manifestation of Alzheimer's disease (AD), Many behavioral disorders have been described in the clinical course of both FTD and AD; however, apathy and personality changes characterize frontal dementias, while depression dominates in AD, at least in the earlier stages. Depending on the distribution of neural damage, different patterns of noncognitive manifestations may be expected in different subtypes of FTD, Recent research on the social cognition deficit in FTD has offered new insights into the relationship between cognition and behavior, suggesting that some aspects of the behavioral changes in dementia may be generated by impairment in this domain.

Cognitive neuroscience of delusions in aging

Assessments and clinical understanding of late-onset delusions in the elderly are inconsistent and often incomplete. In this review, we consider the prevalence, neurobehavioral features, and neuroanatomic correlations of delusions in elderly persons - those with documented cognitive decline and those with no evidence of cognitive decline. Both groups exhibit a common phenotype: delusions are either of persecution or of misidentification. Late-onset delusions show a nearly complete absence of the grandiose, mystical, or erotomanic content typical of early onset psychoses. Absent also from both elderly populations are formal thought disorders, thought insertions, and delusions of external control. Neuroimaging and behavioral studies suggest a frontotemporal localization of delusions in the elderly, with right hemispheric lateralization in delusional misidentification and left lateralization in delusions of persecution. We propose that delusions in the elderly reflect a common neuroanatomic and functional phenotype, and we discuss applications of our proposal to diagnosis and treatment.

Neuropsychological functioning and delusions in dementia: a pilot study

The present pilot study investigated the pattern of neuropsychological functioning associated with the presence of delusions in mild-to-moderate dementia. Participants, all of whom met criteria for dementia, were divided into two groups, delusional (n = 9) and non-delusional (n = 9). Individuals with hallucinations were excluded. Participants completed a neuropsychological test battery. Global cognitive functioning (MMSE) and behavioral disturbance (BEHAVE-AD) were also assessed. Differences between the delusional and non-delusional group were most marked for immediate recall of stories, which was higher in the non-delusional group. Scores on semantic fluency, attention (mental control), and overall cognitive functioning (MMSE) were also lower in the delusional group. Conversely, simple attention span (Digit Span) was within normal limits in both groups. Floor effects were noted on measures of delayed recall and alternating attention. This study supports previous findings of greater neuropsychological impairment in delusional as compared to non-delusional individuals with dementia. However, some areas of cognitive functioning may be relatively preserved. Future research should examine semantic processing in persons with dementia with and without delusions.

Delusional misidentification

The Capgras syndrome and other forms of delusional misidentification may be encountered frequently in neuropsychiatric settings. DMS can occur in the presence of idiopathic psychiatric illness, in diffuse brain illness such as dementia, and in focal neurologic disease. In patients who have focal lesions, there is evidence that right hemisphere damage is necessary for the production of DMS. Although DMS is associated with a pattern of neuropsychologic impairments in the domains of memory, perception, and executive function, these impairments alone do not account for the selectivity and delusional nature of DMS. Therefore, other factors such as premorbid psychopathology, motivation, and loss of ego functions may be important in determining which vulnerable patients develop DMS and which do not.

Environmental reduplicative paramnesia in a case of atypical Alzheimer's disease

A 79-year-old patient with neuropathologically confirmed Alzheimer's disease (AD) presented with a selective environmental reduplicative paramnesia (RP), the belief that one or more environments exist simultaneously in two or more physical locations. Clinical presentation and neuropathological examination revealed an atypical form of AD. High neurofibrillary tangle densities were observed in the frontal and temporal association cortex, whereas the parietal and entorhinal cortex, as well as the hippocampus, were nearly spared. These findings are compared to those reported in frontal and frontotemporal variants of AD and discussed in the light of current anatomoclinical models for environmental RP.

Capgras syndrome: a review of the neurophysiological correlates and presenting clinical features in cases involving physical violence

OBJECTIVE

Acts of violence have been frequently reported in cases of Capgras syndrome (CS), a misidentification syndrome characterized by the delusional belief that imposters have replaced people familiar to the individual. CS has been observed in many neuropsychiatric and organic disorders, and neuroimaging studies indicate an association between CS and right hemisphere abnormalities. However, CS has received limited attention from a forensic psychiatric perspective. We propose that elucidating demographic and clinical features noted in cases of violence secondary to CS may highlight important factors in the progression of CS to violence.

METHOD

We review the neurophysiological correlates and clinical factors observed in CS and present characteristics of a series of cases that demonstrate the potential of CS patients for severe physical violence toward the misidentified person.

RESULTS

For patients with CS involving assault, we present and discuss commonly reported demographic and clinical features that may contribute to an increased risk for violence.

CONCLUSIONS

An understanding of the presenting clinical features of CS resulting in aggressive acts may assist clinicians to assess the potential for violence in these patients.

Review of delusions in dementia

Although delusions are common symptoms in dementia and are associated with a number of adverse outcomes, research in this area has been limited. This article attempts to summarize the existing literature on delusions in dementia with respect to known risk factors, etiology, pathogenesis, neurocognitive findings, behavioral symptoms, and treatment. This study reviews all relevant abstracts and articles pertaining to delusions and dementia. The reviewers found that the studies were limited by confusion concerning phenomenology. However, consistent findings show that delusions are associated with certain demographic variables, neuropathologic and neurocognitive findings, adverse behavioral outcomes, and limited treatment response. The authors conclude that further longitudinal studies with better clarification of terminology are required to clarify inconsistencies and shed light on future treatment options.

The prevalence of Capgras syndrome in a university hospital setting

BACKGROUND

Capgras syndrome (CS), the most common type of delusional misidentification syndrome, is the delusional belief that significant people in the patient's life have been replaced by identical doubles. Capgras syndrome is thought to be a rare syndrome which commonly occurs in a psychotic context.

OBJECTIVE

The objective of this study was to estimate the 5-year prevalence rate of CS in a university hospital in-patient setting and determine associated etiological and sociodemographic factors.

METHODS

All patient files and medical records were reviewed in detail for the presence of Capgras syndrome. The sociodemographic variables, clinical manifestations, and psychiatric and medical diagnoses of patients who fulfilled clinical criteria for Capgras syndrome were recorded for statistical evaluation.

RESULTS

The retrospective evaluation of patient files in 920 cases admitted to our psychiatric in-patient unit over 5 years revealed that 12 patients fulfilled the criteria for Capgras syndrome. The crude prevalence of Capgras syndrome in this population during 5-year period was 1.3% (1.8% for females, 0.9% for males). Schizophrenia (50%) was the most common psychiatric diagnosis in these patients. Only two patients presented with an organic etiology underlying Capgras syndrome.

CONCLUSIONS

The results of this study indicate that Capgras syndrome is not a rare syndrome, and commonly occurs during the course of either functional or organic psychotic illness. Age seems to be an important predicting factor for the etiology of psychosis underlying Capgras syndrome.

Capgras' syndrome in dementia with Lewy bodies

We report the occurrence of Capgras' syndrome, or the delusion of doubles, in a patient with dementia with Lewy bodies. The patient believed that several similar-looking impostors had replaced his wife of over 50 years. Uncharacteristically, he adopted a friendly attitude with these impostors. This unusual convivial reaction to the impostors may result from differential involvement of the dual visual pathways processing facial recognition and emotional responses to faces. The delusion resolved spontaneously, coincident with worsening of the dementia. In a retrospective chart review of 18 autopsy-confirmed cases of dementia with Lewy bodies, delusions were reported in 5 subjects (27.8%), of whom 1 had misidentification delusions much like Capgras' syndrome.