What is Reduplicative paramnesia?

Delusions are false or incorrect personal beliefs about the world. It is beliefs that tend to be unusual and anomalous for people that share the same social cultural and subcultural background. It is believes that goes against evidence and science, and even thought the patients are told so by for instance their doctor, they stay with their believes. The inferences they have done of the world need to be extreme in order to call it a delusion. (Maher & Ross, 1984). 

Reduplicative paramnesia is a content-specific delusion where the patient has a subjective belief that a place or object  is being duplicated, that it exist two or more places at the same time . It is a rare condition that has been seen as an organic cause rather than psychiatric. (Politis & Loane, 2012). Often associated with brain injury in the right hemisphere, after frontal or temporal stroke. 

Different types of Reduplicative paramnesia:

There exits 3 types of reduplicative paramnesia including place reduplication, chimeric assimilation and extravagant spatial localization. The first one, place  reduplication includes that the patient believes that two places which has identical features exist at the same time, yet being geographically way from each other. Next one to mention is chimeric assimilation which refers to believing that two places are combined. They can for example tend to believe that there home has been cloned to the hospital they are staying, that their home is the hospital and vice versa. Lastly is the extravagant spatial localization whereof the patient believe that where they are in the current moment, is perceived as being another place (Lee et al., 2011) 

Pathology of Reduplicative Paramnesia

As already mention in most cases reduplicative paramnesia has a neurologic cause, symptoms occurring in patients suffering from an already neurodegenerative disorder as for example stroke, trauma that has effected the head and psychiatric disorders. In addition the cognitive dysfunction are in most cases caused by organic brain pathology, more specifically the right frontal pathology.  According to a study Kapur et al., (1988) there most be a present of right hemisphere and bilateral frontal pathology needed to be present to be able for the disorder to occur. 

                                                References:

Kapur, Turner & King (1988). Reduplicative paramnesia: possible anatomical and neuropsychological mechanisms.PMC: 

Lee, Shinbo, Hinako &Yumi (2011). Reduplicative Paramnesia After a Right Frontal Lesio. Cognitive and Behavioral Neurology: https://journals.lww.com/cogbehavneurol/Abstract/2011/03000/Reduplicative_Paramnesia_After_a_Right_Frontal.6.aspx

Maher, B., & Ross, J. S. (1984). Delusions. SpringerLink. https://link.springer.com/chapter/10.1007/978-1-4615-6681-6_14

Politis & Loane (2012). Reduplicative Paramnesia: A Review. Karger: https://www.karger.com/Article/Abstract/337748