Delusional Supernumerary Phantom Limb Following Right Putaminal Hemorrhage

Abstract

  In this study, we report a 64-year-old female without a history of psychotic illness, who developed delusional supernumerary phantom limb after right putaminal hemorrhage. She had been undergoing artificial dialysis for 8 years due to chronic kidney disease and had a shunt on her left arm. On admission, she presented with severe left hemiplegia, sensory disturbance, and left unilateral spatial neglect. From day 7 after onset, she began to complain that she had another left arm in addition to her paralyzed left arm, which had been removed from her body. She also expressed the belief that she could undergo dialysis using the phantom limb, without having to go herself. On day 27, she reported that a third arm, which could be moved, was protruding from her left shoulder, and she stated that this third arm was “genuine” and that the paralyzed left arm was “not mine.” On day 34, with improvement in the motor function of her left extremities, her delusional phantom limb disappeared. We hypothesized that the phantom limb sensation might have derived from a severe sensory disturbance. We further speculated that the preserved left hemisphere induced various incorrect interpretations of the phantom limb in a situation where the right frontal lobe function to monitor the validity of beliefs was impaired. It is also possible that the content of the delusions was influenced by several psychological factors, including resistance to dialysis and denial of hemiplegia.