An unusual delusion of duplication in a patient affected by Dementia with Lewy bodies

Abstract

BackgroundDementia with Lewy bodies (DLB) is the second most frequent diagnosis of progressive degenerative dementia in older people. Delusions are common features in DLB and, among them, Capgras syndrome represents the most frequent disturbance, characterized by the recurrent and transient belief that a familiar person, often a close family member or caregiver, has been replaced by an identical-looking imposter. However, other delusional conditions near to misidentification syndromes can occur in DLB patients and may represent a major psychiatric disorder, although rarely studied systematically.Case presentationWe reported on a female patient affected by DLB who presented with an unusual delusion of duplication. Referring to the female professional caregiver engaged by her relatives for her care, the patient constantly described the presence of two different female persons, with a disorder framed in the context of a delusion of duplication.A brain 99Tc-hexamethylpropyleneamineoxime SPECT was performed showing moderate hypoperfusion in both occipital lobes, and associated with marked decreased perfusion in parieto-fronto-temporal lobes bilaterally.ConclusionsAn occipital hypoperfusion was identified, although in association with a marked global decrease of perfusion in the remaining lobes. The role of posterior lobes is certainly important in all misidentification syndromes where a natural dissociation between recognition and identification is present. Moreover, the concomitant presence of severe attentional and executive deficits evocative for a frontal syndrome and the marked global decrease of perfusion in the remaining lobes at the SPECT scan also suggest a possible dysfunction in an abnormal connectivity between anterior and posterior areas.Electronic supplementary materialThe online version of this article (doi:10.1186/s12883-017-0842-1) contains supplementary material, which is available to authorized users.

‘She is not my wife’: a rare and complicated case of Capgras syndrome

“…Another recent case report by Solla and colleagues 5 described a female patient affected by Lewy body dementia. This patient referred to her caregiver as two different female persons 5 . This was suggestive of a delusional disorder of duplication.…”

“…This patient referred to her caregiver as two different female persons. 5 This was suggestive of a delusional disorder of duplication. The case report described a brain single-photon emission CT scan demonstrating moderate hypoperfusion in the frontal, temporal, parietal, and occipital lobes bilaterally.…”

Case Report: De Clerambault's Syndrome in Dementia With Lewy Bodies

“…More than 50% of these patients develop delusions in the mild stages (clinical dementia rating, 0.5) ( 20 ). There have been some reports on patients with DLB and unusual delusions, such as Othello syndrome ( 11 ), delusional parasitosis ( 21 , 22 ) and delusion of duplication ( 23 ). In particular, Othello syndrome, characterized by delusional beliefs of infidelity of a partner, was known to be found in as much as 26.3% of DLB ( 11 ).…”