Delusional misidentification in association with parkinsonism

Parkinson disease psychosis: from phenomenology to neurobiological mechanisms

Parkinson disease (PD) psychosis (PDP) is a spectrum of illusions, hallucinations and delusions that are associated with PD throughout its disease course. Psychotic phenomena can manifest from the earliest stages of PD and might follow a continuum from minor hallucinations to structured hallucinations and delusions. Initially, PDP was considered to be a complication associated with dopaminergic drug use. However, subsequent research has provided evidence that PDP arises from the progression of brain alterations caused by PD itself, coupled with the use of dopaminergic drugs. The combined dysfunction of attentional control systems, sensory processing, limbic structures, the default mode network and thalamocortical connections provides a conceptual framework to explain how new incoming stimuli are incorrectly categorized, and how aberrant hierarchical predictive processing can produce false percepts that intrude into the stream of consciousness. The past decade has seen the publication of new data on the phenomenology and neurobiological basis of PDP from the initial stages of the disease, as well as the neurotransmitter systems involved in PDP initiation and progression. In this Review, we discuss the latest clinical, neuroimaging and neurochemical evidence that could aid early identification of psychotic phenomena in PD and inform the discovery of new therapeutic targets and strategies.

Delusion and Delirium in Neurodegenerative Disorders: An Overlooked Relationship?

Delusions are part of the neuropsychiatric symptoms that patients suffering from neurodegenerative conditions frequently develop at some point of the disease course and are associated with an increased risk of cognitive and functional decline. Delirium is a syndrome characterized by acute onset of deficits in attention, awareness, and cognition that fluctuate in severity over a short time period. Delusions and delirium are frequently observed in the context of neurodegeneration, and their presence can easily mislead clinicians toward a misdiagnosis of psychiatric disorder further delaying the proper treatment. Risk factors for developing delusion and delirium in neurodegenerative conditions have been investigated separately while the possible interplay between these two conditions has not been explored so far. With this study, we aim to achieve a more comprehensive picture of the relationship between delusions and delirium in neurodegeneration by analyzing prevalence and subtypes of delusions in different neurodegenerative disorders; providing an overview of clinical tools to assess delusions in neurodegenerative patients and how delusions are covered by delirium assessment tools and discussing the possible common pathophysiology mechanisms between delusion and delirium in neurodegenerative patients. A more extensive characterization of the relationship between delusions and delirium may help to understand whether delusions may constitute a risk factor for delirium and may ameliorate the management of both conditions in patients with neurodegenerative disorders.

[Delusional misidentification syndromes: A factor associated with violence? Literature review of case reports]

OBJECTIVES

Delusional misidentification syndromes (DMS) correspond to the delusional belief of misidentification of familiar persons, places or objects and to the conviction that they have been replaced or transformed. Several cases of patients who developed violent behavior while suffering from DMS have been published. This led some authors to consider patients with DMS at risk of violence. However, only a few studies have focused on the potential relationship between violence and DMS. The aim of our study was to explore this relationship with a literature review of published cases of patients having committed violent acts associated to DMS.

METHODS

A systematic literature search was conducted on PubMed up to January 2017 using the following term combination "misidentification" and "violence" Fifteen cases of patients with DMS who had committed violent acts were identified. The data from these descriptions were analyzed and synthetized.

RESULTS

Most of the patients were men with a diagnosis of schizophrenia and Capgras syndrome. Acts of violence were severe with a relatively high number of murders or attempted murders. For half of the patients these violent acts were perpetrated with weapons. Victims were regularly the patient's family members and the assaults were usually not planned. Delusional syndromes often progressed for several years. Importantly, substance abuse, which is known to increase the risk of violence in patients with schizophrenia, was only observed in two patients.

CONCLUSION

DMS are associated with several risk factors of violence, such as a diagnosis of schizophrenia, specific delusions including megalomania, persecution, negative affects and identified targets. Despite this risk for severe violence, there are no existing guidelines on how to assess and treat DMS in schizophrenia. Accordingly, we propose (1) the establishment of formal diagnostic criteria, (2) the development of rigorous research on these syndromes and (3) the integration of DMS in assessment of violence risk in schizophrenic patients.

Parkinson's disease psychosis: presentation, diagnosis and management

Parkinson's disease is a neurodegenerative disorder characterized by motor and nonmotor symptoms. Psychosis is a common feature of Parkinson's disease. Parkinson's disease psychosis (PDP) encompasses minor phenomena (illusions, passage hallucinations and presence hallucinations), visual and nonvisual hallucinations and delusions. PDP is associated with reduced function and quality of life. The initial management approach should focus on identification and treatment of any contributory medical factors, reduction or discontinuation of medications with potential to induce or worsen psychosis, nonpharmacological strategies and consideration of acetylcholinesterase inhibitor treatment in the setting of dementia. Pimavanserin, quetiapine and clozapine may all be considered for use in PDP. In this review, we discuss the presentation, diagnosis and management of PDP.

Capgras delusion for animals and inanimate objects in Parkinson's Disease: a case report

BACKGROUND

Capgras delusion is a delusional misidentification syndrome, in which the patient is convinced that someone that is well known to them, usually a close relative, has been replaced by an impostor or double. Although it has been frequently described in psychotic syndromes, including paranoid schizophrenia, over a third of the documented cases of Capgras delusion are observed in patients with organic brain lesions or neurodegenerative disease, including Parkinson's Disease. Variants of Capgras involving animals or inanimate objects have also been described. The etiology of Capgras in Parkinson's remains unclear, but may arise from a combination of factors, such as frontal lobe dysfunction and dopaminergic medication.

CASE PRESENTATION

We present the case of a 53-year old right-handed female with Parkinson's disease who developed Capgras delusion during treatment with dopamine agonists and Levodopa/Carbidopa. She became convinced that her pet dogs and the plants in her garden had been substituted by identically looking ones. Our patient was initially treated with Quetiapine, with no improvement, and subsequently treated with Clozapine, which lead to partial regression of her symptoms. Neuropsychological Evaluation showed Mild Cognitive Impairment in Executive Functions.

CONCLUSIONS

Given the clinical history, onset and evolution of symptoms we believe our patient's delusion resulted from the overlap of dopaminergic medication and Mild Cognitive Impairment in executive functions. Zoocentric Capgras, the variant we describe, has been rarely described in scientific literature, and we believe it is of interest due to its unusual characteristics.

Behavioral effects of levodopa

In recent years, levodopa-induced behavioral changes have received increased attention in the medical literature and in clinical practice. The spectrum of these symptoms includes non-motor fluctuations with neuropsychiatric symptoms, compulsive behaviors such as punding, dopamine dysregulation syndrome, and impulse control disorders, psychosis and hallucinations, as well as hypomania and mania. Despite knowledge of the clinical features associated with these behaviors, many of them are probably underdiagnosed. Although the mechanisms underlying behavioral symptoms are still incompletely understood, recent data from imaging and pathological studies have increased our understanding and guided new treatment strategies. Appropriate management remains challenging, because reduction of levodopa (l-dopa) and dopaminergic treatment is often recommended; however, doses required for control of motor symptoms may still induce behavioral changes. Newer modes of delivery of dopaminergic treatment, deep brain stimulation, and nondopaminergic agents may either provide alternatives for treatment of these behavioral problems or permit treatment of parkinsonism with less risk of these behavioral disorders.

The spectrum of cognitive impairment in Lewy body diseases

Cognitive impairment represents an important and often defining component of the clinical syndromes of Lewy body disorders: Parkinson's disease and dementia with Lewy bodies. The spectrum of cognitive deficits in these Lewy body diseases encompasses a broad range of clinical features, severity of impairment, and timing of presentation. It is now recognized that cognitive dysfunction occurs not only in more advanced Parkinson's disease but also in early, untreated patients and even in those patients with pre-motor syndromes, such as rapid eye movement behavior disorder and hyposmia. In recent years, the concept of mild cognitive impairment as a transitional or pre-dementia state in Parkinson's disease has emerged. This has led to much research regarding the diagnosis, prognosis, and underlying neurobiology of mild cognitive impairment in Parkinson's disease, but has also raised questions regarding the usefulness of this concept and its application in clinical and research settings. In addition, the conundrum of whether Parkinson's disease dementia and dementia with Lewy bodies represent the same or different entities remains unresolved. Although these disorders overlap in many aspects of their presentations and pathophysiology, they differ in other elements, such as timing of cognitive, behavioral, and motor symptoms; medication responses; and neuropathological contributions. This article examines the spectrum and evolution of cognitive impairment in Lewy body disorders and debates these controversial issues in the field using point-counterpoint approaches.

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.

Delusional misidentification syndrome and other unusual delusions in advanced Parkinson's disease

BACKGROUND

Unusual delusional syndromes are rare protean diseases with speculative etiopathogenic mechanisms.

METHODS

Seven consecutive patients with advanced PD were evaluated over a 15-year period at the Movement Disorders Unit in the Neurology Service, Hospital de Clínicas, Federal University of Paraná, and the Paraná State Parkinson's Patients Association.

RESULTS

We describe advanced Parkinson's disease patients presenting with unusual delusional syndromes, including cases of Ekbom, Othello, Capgras' and Diogenes syndromes, reduplicative paramnesia and mirrored-self misidentification.

CONCLUSION

There are a few isolated reports of unusual neuropsychiatric disorders in patients with PD. We believe that these syndromes associated with advanced PD in elderly patients presenting with cognitive impairment and polypharmacy are probably often underestimated. Neurologists should be aware for these rare and treatable conditions.

Capgras syndrome in Dementia with Lewy Bodies

BACKGROUND

Capgras syndrome is characterized by the recurrent, transient belief that a person has been replaced by an identical imposter. We reviewed clinical characteristics of Dementia with Lewy Bodies (DLB) patients with Capgras syndrome compared to those without Capgras.

METHODS

We identified 55 consecutive DLB patients (11 cases with Capgras syndrome (DLB-C) and 44 cases without evidence of Capgras (DLB). Semi-structured interviews with the patient and an informant, neurological exams, and neuropsychological testing were performed. Caregivers were assessed for caregiver burden and depression. Primary comparisons were made between DLB-C and DLB. Exploratory analyses using stepwise logistic regression and bootstrap analyses were performed to determine clinical features associated with Capgras.

RESULTS

DLB-C patients experienced more visual hallucinations and self-reported anxiety, had higher scores on the Neuropsychiatric Inventory, and were less likely to be treated with cholinesterase inhibitors at time of initial evaluation. Extrapyramidal symptoms and depression were not associated with Capgras. Caregivers of DLB-C patients had higher caregiver burden. DLB-C was associated with self-reported anxiety (OR = 10.9; 95% CI = 2.6-47.6). In a bootstrap analysis, clinical findings that were predictors of Capgras included visual hallucinations (log(OR) = 18.3; 95% CI = 17.9-19.3) and anxiety (log(OR) = 2.9; 95% CI = 0.31-20.2).

CONCLUSIONS

Our study suggests that Capgras syndrome is common in DLB and usually occurs in the presence of anxiety and visual hallucinations, suggesting related etiopathogenesis. Early appreciation of Capgras syndrome may afford the opportunity to alleviate caregiver burden and improve patient and caregiver outcomes.

An effective environmental intervention for management of the 'mirror sign' in a case of probable Lewy body dementia

The term 'mirror sign' refers to the inability to recognize the reflection of oneself in a mirror, while the ability to recognize others' faces often remains intact. In this article, we present a case of an 85-year-old woman, with probable Lewy body dementia, who stably exhibited a delusional 'mirror sign' for a period of 9 months. Following a straightforward, ecological, non-pharmacological intervention, her 'mirror sign' delusion was no longer present.

[Capgras syndrome: a proposal of neuropsychological battery for assessment]

Capgras syndrome is the most prevalent of the delusional misidentification syndromes. It appears in both psychiatric illness and organic brain damage. Cognitive and neuropsychiatric models (lateralization and disconnection) have been proposed to explain the syndrome. From a neuropsychological point of view Capgras syndrome seems to be due to damage of bifrontal and right limbic and temporal regions. Memory, feeling of familiarity, monitoring of self and reality would be altered. All of these cause a failure to adequately integrate the information about emotions and facial recognition. Relative preservation of the left frontal lobe may be necessary for the development of delusional response. There does not seem to be a differential pattern as regards the aetiology, but there is a common underlying neuropsychiatric mechanism. Based on theoretic models, and clinics features, we propose a neuropsychological battery to assess the Capgras syndrome, that should be sensitive to the main expected deficits.

The serotonergic system in Parkinson's disease

Although the cardinal manifestations of Parkinson's disease (PD) are attributed to a decline in dopamine levels in the striatum, a breadth of non-motor features and treatment-related complications in which the serotonergic system plays a pivotal role are increasingly recognised. Serotonin (5-HT)-mediated neurotransmission is altered in PD and the roles of the different 5-HT receptor subtypes in disease manifestations have been investigated. The aims of this article are to summarise and discuss all published preclinical and clinical studies that have investigated the serotonergic system in PD and related animal models, in order to recapitulate the state of the current knowledge and to identify areas that need further research and understanding.

Capgras Syndrome associated with the use of psychoactive substances

INTRODUCTION

Capgras syndrome has originally been described as psychiatric syndrome. However, in the last few years reports of patients with this syndrome has significantly increased in patients with neurological, metabolic, and infectious diseases and those who consume alcohol. Different hypotheses have been proposed to explain the neurobiology of this very unusual symptom, such as changes in the dopamine circuit and specific dysfunctions in facial processing.

CASE

In this work we present a new case of Capgras syndrome, associated with an acute cocaine overdose, which was transient and reversible.

DISCUSSION

The neurobiological bases of this syndrome are analysed, along with their relationship with the changes induced by cocaine use. Thus, Capgras syndrome could be the expression of functional changes at frontal-temporal level, and the paralimbic region secondary to the consumption of psychoactive substances such as cocaine.

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.

Cognitive deficits and psychosis in Parkinson's disease: a review of pathophysiology and therapeutic options

Parkinson's disease is a neurodegenerative disorder causing not only motor dysfunction but also cognitive, psychiatric, autonomic and sensory disturbances. Symptoms of dementia and psychosis are common: longitudinal studies suggest that up to 75% of patients with Parkinson's disease may eventually develop dementia, and the prevalence of hallucinations ranges from 16-17% in population-based surveys to 30-40% in hospital-based series. These cognitive and behavioural features are important in terms of prognosis, nursing home placement and mortality. The pattern of cognitive deficits in Parkinson's disease is variable, but often includes executive impairment similar to that seen in patients with frontal lesions, as well as episodic memory impairment, visuospatial dysfunction and impaired verbal fluency. The most common manifestation of psychosis in Parkinson's disease is visual hallucinations, but delusions, paranoid beliefs, agitation and florid psychosis can also occur. An understanding of the pathophysiology underlying these symptoms is essential to the development of targeted therapeutic strategies. Post-mortem studies suggest an association between Lewy body deposition and dementia in Parkinson's disease, and indeed Parkinson's disease and dementia with Lewy bodies may form part of the same disease spectrum. Whether Lewy bodies actually play a causative role in cognitive dysfunction, however, is unknown. Deficits in neurotransmitter systems provide more obvious therapeutic targets and dysfunction of dopaminergic, cholinergic, noradrenergic and serotonergic systems have all been implicated; these may each underlie different features of Parkinson's disease dementia, perhaps explaining some of the heterogeneity of the syndrome. Psychosis has traditionally been considered as a dopaminergic drug-induced phenomenon, but factors intrinsic to the disease process itself also cause hallucinations and delusions. These factors may include Lewy body deposition in the limbic system, cholinergic deficits and impairments of primary visual processing. Therapeutic intervention for cognitive and behavioural symptoms in Parkinson's disease currently focuses on two main groups of drugs: cholinesterase inhibitors and atypical antipsychotics. A recent large, randomised, controlled trial suggests that cholinesterase inhibitors can produce a modest improvement in cognitive function, as well as psychotic symptoms, generally without an adverse effect on motor function. Certain atypical antipsychotics allow hallucinations, delusions and behavioural problems to be brought under control with minimal deleterious effects on motor function and cognition, but their safety in elderly patients has recently been called into question. Deep brain stimulation does not appear to be a useful treatment for cognitive and psychiatric dysfunction in patients with Parkinson's disease. Modafinil improves alertness in Parkinson's disease and warrants further investigation to establish its effects on cognitive performance.

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.

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.

Psychophysiological evidence for altered information processing in delusional misidentification syndromes

Recent research provides evidence that delusional misidentification syndromes (DMS) are associated with cognitive deficits. However, the underlying mechanisms of these deficits are not known. Since the P300 component of event-related potentials (ERPs) is related to fundamental aspects of working memory (WM), the present study is focused on P300 elicited during a WM test in DMS patients, as compared to those of healthy controls. Nine patients with DMS and 11 healthy controls, matched for age, sex and educational level were tested with a computerized version of the digit span test of the Wechsler batteries. Auditory ERPs were measured during the anticipatory period of the test. DMS patients showed significant reductions in P300 amplitude at the right frontal region compared to healthy controls. P300 latency in the central midline brain region was significantly prolonged in the DMS group. Each of these measures classified correctly 90% of the two groups. Moreover, the memory performance of the patient group was significantly lower, relatively to healthy controls. These findings provide evidence supporting the suggestion that DMS is associated with psychophysiological alterations occurring at the right frontal region, which mediates automatic processes, as well as with an irregular allocation of attentional resources, involving the interhemispheric circuitry, possibly due to gray matter degeneration. Finally, present work points to a need for further research investigating the characteristics, causes, course and treatment of severe cognitive deficits associated with DMS.

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.

Parkinson's disease: the treatment of drug-induced hallucinations and psychosis

Drug-induced psychosis is one of the most disabling complications of advancing Parkinson's disease. It has also been one of the most difficult to treat. Clozapine was the first medication shown to be safe and effective in this setting, and it remains the standard by which newer atypical antipsychotics are measured. However, due to the small but significant risk of agranulocytosis and the need for frequent blood testing, alternatives have been sought. Risperidone, olanzapine, and quetiapine are new atypical antipsychotics that have each been proposed as an alternative to clozapine, but the literature concerning their use in Parkinson's disease is conflicted and confusing. Although quetiapine appears to be the best current choice, none of these medications have equaled clozapine's ability to safely treat drug-induced psychosis without the risk of worsening parkinsonism.

Multiple fregoli delusions after traumatic brain injury

A 61 year old man after a traumatic brain injury resulting in right frontal and left temporoparietal contusions developed florid Fregoli-type misidentifications. Extensive neuropsychological testing demonstrated significant deficits in executive and memory functions. The patient's neuropsychological profile closely resembled that seen in previously reported patients with Capgras syndrome. Our findings are consistent with the hypothesis that a combination of executive and memory deficits may account for cases of delusional misidentification associated with brain lesions. However, the form which the delusion takes may be influenced by other factors including motivation.