Reduplicative paramnesia for places: A comprehensive review of the literature and a new case report

Delusional belief about location ("reduplicative paramnesia")

INTRODUCTION

People admitted to hospital as inpatients following head injury or stroke sometimes form the delusional belief that they are located somewhere else-often, near or in their home. This delusion was first described by Pick, who named it "reduplicative paramnesia"; we argue instead for the term "location delusion".

METHODS

We carried out a literature search and identified 112 cases of location delusion published since Pick's original 1903 case.

RESULTS

We found that, in this cohort of patients, the belief about being located elsewhere than the hospital is elaborated into more specific delusional beliefs about just where the patient is located (e.g., beliefs that involve mislocation of the hospital). We identified eight specific location beliefs and offered a two-factor motivational explanation of these eight forms of location delusion. The patient wishes to be somewhere more congenial, that wish becomes a hypothesis (as occurs in normal belief formation), and then, because these patients have impaired ability to evaluate hypotheses, the hypothesis is accepted and maintained as a (delusional) belief.

CONCLUSION

Our previous papers on the two-factor theory of delusional belief focussed on fully neuropsychological delusions. Here we propose that this theory can also explain delusions generated by motivational influences.

Everything in its right place: a case report of reduplicative paramnesia with therapeutic and theoretical considerations

Introductions: Reduplicative paramnesia (RP) is a rare and poorly understood phenomenon in which a person believes the place they are in has been replicated and exists in two places at once. There is minimal extant theoretical work addressing possible cognitive mechanisms subtending RP.Method: We present a new case of RP and discuss the therapeutic and theoretical implications of this case for the management and understanding of this phenomenon. Using the hypothetico-deductive approach to a neuropsychological case, we examine the phenomenon in the light of one and two-factor approaches to understanding the genesis of delusions.Results: The individual discussed in this case showed some evidence of relatively efficient incorporation of new evidence (belief updating) despite concurrently maintaining a delusional belief system.Conclusion: This case raises novel challenges for the two-factor account of neurological delusions.

Oh it's me again: Déjà vu, the brain, and self-awareness

Déjà vu and involuntary autobiographical memories (IAMs) are differentiated by a number of factors including metacognition. In contrast to IAMs, déjà vu activates regions associated with self-awareness including the right dorsolateral prefrontal cortex.

The neuropsychology and neuroanatomy of reduplicative paramnesia

Reduplicative paramnesia refers to the delusional belief that there are identical places in different locations. In this case-control study we investigated the clinical, phenomenological, neuropsychological and neuroanatomical data of eleven patients with reduplicative paramnesia and compared them against a control group of eleven patients with severe spatial disorientation without signs of reduplicative paramnesia. We show that most patients with reduplicative paramnesia report that a current place is reduplicated and/or relocated to an other familiar place. Patients with reduplicative paramnesia show a higher prevalence of deficits in the executive functions compared to the control patients, while mnestic and visuo-spatial deficits were both frequent in patients with reduplicative paramnesia and the control group. Patients with reduplicative paramnesia mostly suffer from right hemispheric lesions with a maximal overlap in the dorsolateral prefrontal cortex. Using lesion network mapping we show that lesions causing reduplicative paramnesia are connected to bilateral anterior insula and the right cingulate cortex. We argue that patients with reduplicative paramnesia fail to integrate the actual context with visuo-spatial memories and personal relevant emotional information due to a disruption of the neural network within the anterior temporal lobe, the cingulate cortex and the anterior insula. Also patients with reduplicative paramnesia are not able to resolve this conflict due to the lesion of the dorsolateral prefrontal cortex and executive dysfunction.

Clinical presentation and neural correlates of stroke-associated spatial delusions

BACKGROUND AND PURPOSE

Incongruent beliefs about self-localization in space markedly disturb patients' behavior. Spatial delusions, or reduplicative paramnesias, are characterized by a firm conviction of place reduplication, transformation, or mislocation. Evidence suggests they are frequent after right hemisphere lesions, but comprehensive information about their clinical features is lacking.

METHODS

We prospectively screened 504 acute right-hemisphere stroke patients for the presence of spatial delusions. Their behavioral and clinical features were systematically assessed. Then, we analyzed the correlation of their duration with the magnitude of structural disruption of belief-associated functional networks. Finally, we described the syndrome subtypes and evaluated whether the clinical categorization would be predicted by the structural disruption of familiarity-associated functional networks using an unsupervised k-means clustering algorithm.

RESULTS

Sixty patients with spatial delusions were identified and fully characterized. Most (93%) localized the misidentified places closer to home than the hospital. The median time duration was 3 days (interquartile range = 1-7 days), and it was moderately correlated with the magnitude of structural-functional decoupling of belief-associated functional networks (r = 0.39, p = 0.02; beta coefficient regressing for lesion volume = 3.18, p = 0.04). Each clinical subtype had characteristic response patterns, which were reported, and representative examples were provided. Clustering based on structural disruption of familiarity- and unfamiliarity-associated functional networks poorly matched the clinical categorization (lesion: Rand index = 0.47; structural disconnection: Rand index = 0.51).

CONCLUSIONS

The systematic characterization of the peculiar clinical features of stroke-associated spatial delusions may improve the syndrome diagnosis and clinical approaches. The novel evidence about their neural correlates fosters the clarification of the pathophysiology of delusional misidentifications.

Mapping delusions of space onto a structural disconnectome that decouples familiarity and place networks

Interpretation of space is an important determinant of human behaviour. Delusions of space, or reduplicative paramnesias, are a particularly disturbing form of spatial disorientation characterized by the patients' strong belief of place reduplication, transformation or mislocation. Their occurrence following focal brain damage provides a unique opportunity to unveil the structural-functional basis of space misinterpretations. First, we identified reports of lesion-associated reduplicative paramnesias with brain images available through a systematic review of the literature (n = 24). Each lesion was matched with 4 stroke controls and the sample was randomly split in an exploratory (n = 60) and in a validation (n = 60) dataset. Second, we used 178 7T tractographies to compute structural disconnectome maps and analysed lesion topography and disconnection patterns. Delusions of space were significantly associated with structural disconnection of right ventrolateral prefrontal and right temporal regions, and this finding was replicated in the validation sample. Third, we performed a functional meta-analysis of syndrome-related terms. We demonstrated that the structural disconnectomes of delusions of space were spatially correlated with the functional meta-analytic maps of familiarity and place, and replicated the previous evidence that the lesion topography maps are spatially correlated with belief-related functional networks. No association was found with control terms. These results reveal that structural disconnection putatively mediates functional changes associated with reduplicative paramnesias and provide a possible neural basis for the content specificity for places that characterizes these delusional beliefs.