Reduplicative paramnesia after right basal ganglia hemorrhage

Abstract

Background Reduplicative paramnesia (RP) is a delusional misidentification syndrome first described by Arnold Pick in which individuals believe they are in a duplicate location. RP can manifest as place reduplication, chimeric assimilation, or confabulatory mislocation, with parallels to person misidentification syndromes like Capgras and Fregoli. Though associated with various conditions, stroke-induced lesions are the most common cause, as evidenced by studies identifying brain network disruptions linked to RP. Case presentation This case study involves a 71-year-old hypertensive male who presented with a right-sided caudate nucleus hemorrhage, leading to intensive care, ventricular drainage, and rehabilitation. Fourteen months post-stroke, the patient exhibited delusional beliefs that his apartment had been swapped with a similar one in another town. Comprehensive neuropsychological assessment and advanced neuroimaging were performed to elucidate the underlying neural correlates. Neuropsychological testing revealed normal verbal memory and interference control but significant deficits in spatial perception and memory for geometrical shapes. Neuroimaging identified a lesion centered upon the right caudate nucleus, consistent with structural disconnection maps associated with RP. Conclusions This case highlights RP as complication following stroke, in this case due to functional disconnection of frontal and temporal regions on the right hemisphere. The findings underscore the importance of considering RP in differential diagnoses of post-stroke confusion and the potential utility of advanced imaging techniques in identifying at-risk patients.