Delusional Misidentification Syndromes in Neurological Disorders

Delusional misidentification syndromes (DMS) encompass a group of striking disturbances in person recognition, most notably Capgras syndrome, in which a familiar individual is perceived as an impostor. Variants include Fregoli syndrome, involving the belief that different people are a single persecutory individual in disguise, and intermetamorphosis, in which one person is believed to transform into another. These syndromes arise in a spectrum of neurological conditions—from neurodegenerative diseases such as Alzheimer’s or Lewy body dementia to focal brain lesions, stroke, epilepsy and demyelinating disorders. Contemporary models emphasise a dual-route framework of face processing: one route supporting conscious recognition and another mediating autonomic emotional response. Disruption of connectivity between temporal–occipital face-processing areas and limbic or frontal circuits is thought to precipitate a mismatch between intact perceptual identification and impaired affective tagging, giving rise to fixed, monothematic delusions. Clinically, DMS carry implications for patient safety, carer burden and management strategies, necessitating interdisciplinary assessment using neuroimaging, detailed neuropsychology and targeted pharmacotherapy.

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Delusional Misidentification Syndromes in Neurological Disorders publication trend

The graph below shows the total number of articles in delusional misidentification syndromes in neurological disorders across all publications each year (not limited to Nature Index journals).

Technical terms

Dual-route model: A theoretical framework positing separate neural pathways for conscious recognition of identity and for affective response to familiar stimuli.

Monothematic delusion: A fixed false belief focused on a single theme or topic, often impervious to contradictory evidence.

Prosopagnosia: Impairment of overt face recognition due to lesions in the fusiform gyrus, used as a contrast to DMS.

Interoception: The neural representation of internal bodily states, crucial for linking autonomic signals with emotional recognition.

Temporoparietal junction: A cortical hub integrating visual and self-referential information, often implicated in misidentification phenomena.

References

1. Nature and extent of person recognition impairments associated with Capgras syndrome in Lewy body dementia. Frontiers in Human Neuroscience (2014).
2. Capgras Syndrome Due to Cannabinoids Use: A Case Report With Radiological Findings. Cureus (2022).
3. Delusional Misidentification Syndromes: Untangling Clinical Quandary With the Newer Evidence-Based Approaches. Cureus (2021).
4. Capgras Syndrome, Multiple Sclerosis, and COVID-19 Infection: A Case Report. Cureus (2024).
5. Face Processing Impairments and Delusional Misidentification. Behavioural Neurology (1990).