NCIt definition : A rare neuropsychiatric disorder whose primary feature is the delusion that relatives
or close acquaintances are not the persons that they are known to be. Visual recognition
appears intact but familiar persons are thought be imposters, that is, they appear
similar or identical to known individuals but are not. Most cases are seen in the
context of a psychotic state. However, if manifested post-traumatically, the cause
is most likely due to neurologic impairment. This disorder should be contrasted with
prosopagnosia, in which an individual may not recognize a familiar person at all.;