autotopagnosia

   Also known as autotopoagnosia and somatotopagnosia. The term autotopagnosia comes from the Greek words autos (self), topos (place), a (not), and gnosis (insight). It translates loosely as 'not being able to recognize a body part of oneself'. The term was introduced in or shortly before 1908 by the German psychiatrist and neurologist Arnold Pick (1851-1924). Today it is used to denote a condition characterized by the inability or strongly diminished ability to recognize, denominate, or indicate a part of one's body, and in some definitions a body part belonging to someone else. Today the term heterotopagnosia is used largely to denote the symptom's latter connotation. Still broader definitions, however, also include the inability or diminished ability to recognize, denominate, or indicate body parts in a picture. When there is an inability or strongly diminished ability to recognize, denominate, or indicate objects in general, the term allo-topagnosia is used. Because autotopagnosia is often accompanied by comorbid symptoms such as anomia, apraxia, visuo-spatial dysfunction, and/or global cognitive dysfunction, descriptions of 'pure' autotopagnosia are rare. Pathophysio-logically, autotopagnosia is associated primarily with discrete lesions affecting the neural pathways connecting the parietal lobe and the thalamus (such as the corona radiata, for example). Etio-logically, the condition is associated with a variety of processes capable of inflicting such discrete lesions, including infectious disease, vascular disease, neoplasms, and multiple sclerosis. Pick has been credited not only with naming but also with describing autotopagnosia for the first time in 1908. In Pick's opinion, however, in autotopagnosia the ability to denominate body parts is preserved although the ability to recognize or indicate them is absent. For a long time autotopagnosia was considered an artefact of conditions such as aphasia, neglect, or cognitive impairment. Today, however, there is increasing support for the view that it may constitute a discrete symptom indicative of an impairment of body-specific visual representation. Autotopagnosia tends to be classified either as an agnosia or as a pointing disorder. *Negative autoscopy (i.e. a phenomenon characterized by the inability to recognize one's own reflection in the mirror) is sometimes classified as a variant of autotopagnosia. Autotopagnosia should not be confused with *body schema illusions.

   References

   Pick, A. (1908). Ueber Störungen der Orientierung am eigenen Körper. Arbeiten aus der Deutschen Psychiatrischen Universitätsklinik in Prag. Berlin: Karger.

   Hécaen, H., de Ajuriaguerra, J. (1952). Méconnaissances et hallucinations corporelles. Intégration et désintégration de la somatognosie. Paris: Masson et Cie., Éditeurs.

   Degos, J.-D., Bachoud-Levi, A.C., Ergis, A.M., Petrissans, J.L., Cesaro, P. (1997). Selective inability to point to extrapersonal targets after left posterior parietal lesions: An objectiviza-tion disorder? Neurocase, 3, 31-39.

   Guariglia, C., Piccardi, L., Puglisi Allegra, M.C., Traballesi, M. (2002). Is autotopoagnosia real? EC says yes. A case study. Neuropsychologia, 40, 1744-1749.

   Wicky, G. (2005). De l'autotopoagnosie à un modèle de représentations des connaissances du corps. Schweizer Archiv für Neurologie und Psychiatrie, 156, 196-202.