mirror sign

   Also known as signe du miroir and Capgras syndrome for the mirror image. All three terms are used to denote the inability to recognize oneself in a reflecting surface such as a window or a mirror, while the ability to recognize others in such reflecting surfaces is typically intact, as is the ability to recognize oneself in a photograph or a painting. The mirror sign can be classified as a symptom (more specifically, a delusional misidentification symptom) occurring in the context of *mirrored self-misidentification, which itself constitutes a type of *misidentification syndrome. However, competing classifications have also been proposed. The expression signe du miroir was introduced in or shortly before 1927 by the French psychiatrist Paul Abely to denote the need or urge to examine oneself for prolonged and frequent periods in front of a reflecting surface. Abely was under the impression that the mirror sign occurred chiefly in individuals with a clinical diagnosis of dementia praecox and that the affected individual often appeared to be conversing with the image in the mirror. Moreover, Abely speculated that the mirror sign might be a manifestation of narcissism and/or a tendency towards homosexuality. Individuals displaying a mirror sign in the context of Alzheimer's disease may nevertheless act as if they recognize themselves and make use of mirrors and other reflective surfaces to comb their hair, for instance. The prevalence of the mirror sign in individuals with Alzheimer's disease has been reported to be between 2 and 22%. The symptom has also been recorded in association with * post-traumatic stress disorder (PTSD), vascular dementia, and psychotic disorders. Patho-physiologically, the mirror sign can occur in the absence of a demonstrable CNS lesion. When discrete CNS lesions are present, they are typically located in the right hemisphere. They can also present in the form of mild, diffuse, bilateral CNS changes, such as atrophy and periventricular white matter changes. Conceptually, the mirror sign should not be confused with the notions of mirror agnosia (which is characterized by 'reaching into' the mirror, as in neglect) and *mirror hallucination (which is a synonym for the term * autoscopic hallucination).

   References

   Abely, P. (1930). Le signe du miroir dans les psychoses et plus spécialement dans la démence précoce. Annales Médico-psychologiques,1, 28-36.

   Méaulle, D. (2007). Le signe du miroir: Reflets cliniques et théoriques. L'Évolution psychiatrique, 72, 81-97.

   Spangenberg Postal, K. (2005). The mirror sign delusional misidentification symptom.In: The lost self. Pathologies ofthe brain and identity. Edited by Feinberg, T.E., Keenan, J.P. Oxford: Oxford University Press.