Illusory movements of the contralesional hand in patients with body image disorders

Objectives: In the present study, we assess whether illusorysensations of movement can be elicited in patients with rightbrain damage (RBD).Methods: Ten RBD patients (three with disorders of bodilyrepresentations) were asked to report whether movements oftheir right hand induced any illusory somatic or motorsensations. Inquiries on anomalous sensation of movement ofthe left hand were carried out while subjects: 1) observed themoving hand in a mirror propped vertically along theparasagittal plane; 2) looked directly at the moving hand; 3)looked at the still hand; 4) kept their eyes closed. Twelvehealthy subjects served as controls.Results: Movement of the right hand induced a very clearsensation of movement of the left, contralesional hand in twopatients affected by body image disorders. Remarkably, thisoccurred mainly while subjects were looking in the mirror,that is, when conflicts between visual, somatic, and motorinformation were maximal. In no condition did controlsubjects report any consistent anomalous evoked movementor sensation.Conclusions: Illusory movements of the left, plegic handcontingent upon sensorimotor conflicts can be evoked inbrain damaged patients with body image disorders