Delusional misidentification in Parkinson’s disease: report of two cases and a review

ABSTRACT

Syndromes of delusional misidentification consist of disordered familiarity and have been reported in diverse diagnoses, including Parkinson’s disease. Although the most common delusional misidentification is Capgras syndrome, in which the sufferer believes a familiar person has been replaced by an identical imposter, other forms have been also described. The pathogenesis of delusions of misidentification appears to require dysfunction of or connection to a left cerebral cortical area involved in recognition of familiarity, and also right frontal cortex serving belief evaluation. Two cases of Parkinson’s disease with an unusual delusional misidentification, intermetamorphosis, are presented, along with their improvement with pimavanserin, a novel atypical antipsychotic medication.

KEYWORDS:

• Delusional misidentification
• Parkinson’s disease psychosis
• Parkinson’s disease
• pimavanserin

Declaration of interest

N Hermanowicz served as a site investigator for the pivotal trial that led to the FDA approval of pimavanserin for treatment of Parkinson’s disease psychosis. He has received income from Acadia Pharmaceuticals, the manufacturer of pimavanserin, through speakers bureau presentations and as a participant in advisory boards. The author has no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Additional information

Funding

This paper was not funded.