[The man with 6 arms. An analysis of supernumerary phantom limbs after right hemisphere stroke]

Consequently an infarct in the territory of the right middle cerebral artery, a 77-year old man had a complete left sensory motor hemiplegia, with left neglect. For several weeks, he described the existence of one and more supernumerary phantom limbs. The patient's adamant and delusional conviction of their reality caused him considerable distress. Without being anosognosic he was not completely aware of his disorder, and had slight difficulties in judging what was plausible. The mechanisms underlying this delusion concerning specific parts of the body probably involve multifactorial disorders: first, a sensory deafferentation source of a distorsion of the perceived body schema; second, a resulting discrepancy between the perception of the body schema and its innate representation; third abnormalities of self-awareness and of self-judgement, leading the patient to argue forcellully in favor of incongruous rationalizations.