Environmental reduplication or reduplicative paramnesia is one of the content-specific delusions (CSD) which is characterized by reduplication of places. CSD has been reported in focal and diffuse cerebral disorders. A focal lesion such as frontal lobes and the right hemispheric lesion have been documented. The authors describe a 66 year-old woman who had a delusion of misidentification for place one month after right middle cerebral artery occlusion. The patient did not have any history of schizophrenia or other
psychiatric diseases. The patient believed that her car, furniture and house were duplicated. She also mentioned
that her son and friends tried to takeover all of her properties and told everyone that she was insane. The prominent cortical signs were tactile and visual neglect. Neuropsychological assessments revealed poor attention but she had neither confusion nor dementia. Clock drawing and construction tests revealed visuospatial impairment which was compatible with non-dominant hemispheric abnormality. MRI showed evidence of cerebral infarction in the right middle cerebral artery territory. Only one similar patient who had an intracerbral hematoma of the right frontal lobe has been reported in the literature. The role of occipitoparietal and fronto-temporal lobes or their connections in environmental reduplication is proposed.

Keywords: Environmental reduplication, Reduplicative paramnesia, Delusion of misidentification, Right middle cerebral artery occlusion