Modulation of environmental reduplicative paramnesia by perceptual experience

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.

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.

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

Reduplicative paramnesia for places (i.e., the delusional belief that a place has been duplicated or exists in two different locations) is a rare disorder observed in neurological patients. We review the existing literature on the topic, highlighting commonalities and differences among the 51 cases published since the first report in 1903. Our results highlight the combination of multiple factors in the pathogenesis of this monothematic spatial delusion. From a neurological perspective, a crucial role is played by damage to the right frontal and temporal lobe. Deficits of non-verbal memory and executive functions, along with topographical disorientation, appear to be the most common (but, not systematic) cognitive impairments. The clinical picture of the disorder is further complicated by often overlooked psychological and motivational factors. Consequently, the precise neuro-cognitive substrate of this disorder is yet to be described in detail. We stress the need for a more detailed and systematic approach exploiting neurological, neuroimaging, neuropsychological and psychopathological methods. To guide future investigations, we provide clinical- and research-oriented recommendations. Finally, we illustrate the interplay of all above-mentioned factors with a new case report.