capgras syndrome - when dementia misidentifies a...

Interreg-IPA Cross-border Cooperation Programme Romania-Serbia

September 2018

Capgras syndrome - when Dementia misidentifies a face

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Capgras syndrome

• Misidentification syndromes are among the most fascinating and puzzling forms of memory problems that can result from psychiatric or neurological disease. They are monothematic delusions that have intrigued psychologists and philosophers alike for over a century, but have only recently been brought into the area ofscientific investigation.

• Misidentification syndromes have been observed in relation to places, objects, and people, and have

become known collectively as “delusion of misidentification”

General framework

• CS is in close association with psychiatric illness (e. g. paranoid schizophrenia and other psychoses), it was thought for many years that CS is the result of abnormal psychodynamic processes.

• Researches conducted in the past 40 years have attempted to ground CS symptomatology

in brain-based dysfunction within face-processing and person recognition models.

General framework

• Some researchers have endorsed the view that the face recognition deficits in CS are the mirror-image of those observed in prosopagnosia.

• Evidence in support of the idea of deficits in affective reactivity in face recognition come from observations that many cases of CS have

been found to be associated with right prefrontal cortical damage.

General framework

• One hypothesis says that the second pathway is thought to be comprised of limbic structures, such as the amygdala and possibly frontal regions, including the insula and anterior cingulate cortex.

• It has also been suggested that CS could result from a disconnection between ventral visual

structures and limbic structures dedicated to affective processing.

General framework

• Many studies have confirmed that the CS is caused by a variety of etiologies, which revealed reduced autonomic responses.

• It has been hypothesized that the monothematic delusional belief that characterizes CS is a result of the patients’

attempt to “make sense” of the absence of an expected affective signal.

Misidentification

• A defining characteristic of delusions that is also present in CS is that patients will firmly hold on to their delusional beliefs.

Capgras syndrome

• In Lewy body Dementia and Alzheimer’speople can lose their ability to recognize faces. This leads to false belief and it can be incredibly stressful for everyone involved.

Capgras syndrome

• The disorder, known as Campgras Syndromeor Misidentification syndrome is characterizedby the delusional belief that a person withwhom the patient shares a close emotionalbond, typically the spouse, has been replacedby an imposter or a look-alike

Capgras syndrome

• In their study, Western university researchersdemonstrated that person recognitiondifficulties experienced by patient withCampgras syndrome are not restricted to theperson who is the target of their delusion andcan affect recognition of other well-knownindividuals such as famous TV and sports

personalities.

Capgras syndrome

• For faces, such difficulties even extended to recognizing the intensity of emotional facialexpressions.

• Interestingly, name recognition was spared, however.

Capgras syndrome

• The disorder places an enormous burden in patient care in dementia, given that the„imposter“ is usually also the primarycaregiver.

Capgras syndrome

• C. Fiaccoli said that their results suggest that itarises as a consequence of a missingemotional response that normallyaccompanies recognition of close familymembers and other well-known individuals, when we see their faces or hear their voices.

• This missing emotional response is likely theresult of abnormal functioning in theautonomic nervous system.

Conclusion

• Although the majority of CS cases reported in the literature have been associated with psychiatric illness, affective disorders, focal lesion, or traumatic brain injury, recent epdemiological evidence suggests that CS and other related misidentification problems are also often seem as part of neurodegenerative

disease, with a particularly large number of cases associated with DLB.

Study

Original research article

Front. Hum. Neurosci. Sept. 2014

“Nature and extent of person recognition impairments associated with Capgras

syndrome in Lewy body dementia”

by Chris M. Fiacconi, Victoria Barkley, Elizabeth C. Finger, Nicole Carson, Devin duke, R. Shayna

Rosenbaum, Asaf Gilboa and Stefan Kohler.

Thank you!