Delusional misidentification: a clinical, neuropsychological and brain imaging case study.

The case of a young woman with a disorder involving Capgras syndrome, Frégoli syndrome, intermetamorphosis, and the subjective-doubles syndrome is reported. Neuropsychological assessment showed a low efficiency in the complex visuospatial organization tasks and in non-verbal memory. MRI found a left lenticular hypodensity, and two PET scans performed in the symptomatic and recovered states showed significant changes and asymmetries in cerebral glucose metabolism in the frontal, parietal, and subcortical regions. These findings are discussed with respect to recent models of delusional misidentification syndromes.