Cognitive neuropsychiatric analysis of an additional large Capgras delusion case series

Abstract

Introduction:Although important to cognitive neuropsychiatry and theories of delusions, Capgras delusion has largely been reported in single case studies. Bell et al. [2017. Uncovering Capgras delusion using a large scale medical records database. British Journal of Psychiatry Open, 3(4), 179–185] previously deployed computational and clinical case identification on a large-scale medical records database to report a case series of 84 individuals with Capgras delusion. We replicated this approach on a new database from a different mental health service provider while additionally examining instances of violence, given previous claims that Capgras is a forensic risk.Methods:We identified 34 additional cases of Capgras. Delusion phenomenology, clinical characteristics, and presence of lesions detected by neuroimaging were extracted.Results:Although most cases involved misidentification of family members or partners, a notable minority (20.6%) included the misidentification of others. Capgras typically did not present as a monothematic delusion. Few cases had identifiable lesions with no evidence of right-hemisphere bias. There was no evidence of physical violence associated with Capgras.Conclusions:Findings closely replicate Bell et al. (2017). The majority of Capgras delusion phenomenology conforms to the “dual route” model although a significant minority of cases cannot be explained by this framework.

What is Capgras Syndrome? Diagnosis and Treatment Approach

“…The rareness of CS, as well as its impressive clinical manifestation as a colorful syndrome, has caused most publications to present case descriptions as scientific curiosities [8,9]. CS has also attracted the attention of novelists in fictional literature.…”

“…While psychodynamic theories consist of ambivalence theory, depersonalization theory, and regression theory, neurocognitive hypotheses focus on right hemispheric dysfunction, face-recognition processing abnormalities, and focal structural cerebral abnormalities [29]. There are two components of the visual recognition of a familiar face, one of which is responsible for conscious recognition of the face and the remembrance of associated semantic information, while the other is responsible for the limbic-mediated emotional arousal including the feeling of familiarity that accompanies the conscious recognition of a known face [9].…”

“…In the affective circuit, the ventral route from the visual centers to the temporal lobes may be protected, also active in conscious face recognition; however, the dorsal visual track that gives the face its emotional significance is damaged. A brief disruption of the ventral visual pathway leads to prosopagnosia, whereas damage to the dorsal visual areas leads to an impaired sense of familiarity for known faces, as in CS [9,18,30,32]. While the ability to identify that person is intact, patient with CS probably has a brain lesion that interferes with the patient's ability to sense a familiarity toward the significant other [16].…”

Wahnhafte Missidentifikation und gewalttätiges Verhalten – Risikoabschätzung und Management

“…Neben frühen psychodynamischen ätiologischen Modellen (z. B. Ablehnung oder inzestuöses Begehren von Familienangehörigen [19]), verweist bereits Capgras eigener Erklärungsversuch des von ihm beschriebenen Wahns, es komme dabei zu einem "Verlust der affektiven Vertrautheit für Gesichter während der initialen Gesichtserkennung" [1] auf spätere neuropsychologische Erklärungsmodelle [11,[20][21][22]. Seit den Arbeiten von Ellis [23,24] wird angenommen, dass ein Missverhältnis von kognitivem und affektivem Erkennen von Gesichtern besteht.…”

“…Während manche Autoren bereits seit den späten 1980er-Jahren über ein erhöhtes Risiko von Gewalttätigkeit bei WM berichten [2,3,25,26], betonen neuere Arbeiten hierbei einen möglichen Bias durch Einzelfallpublikationen [21,27]. So findet Pandis in seiner aktuellen systematischen Nachuntersuchung von 255 publizierten Fällen mit Capgras-Wahn bei gut einem Drittel der Patienten fremdaggressives Verhalten (bei 4 % sogar mit Tötungsdelikten) und interpretiert dies entweder als möglichen Hinweis für die Gefährlichkeit von WM oder als Ausdruck eines Publikations-Bias [19].…”