Somatoparaphrenia: a body delusion. A review of the neuropsychological literature.
A review of published brain-damaged patients showing delusional beliefs concerning the contralesional side of the body (somatoparaphrenia) is presented. Somatoparaphrenia has been reported, with a few exceptions, in right-brain-damaged patients, with motor and somatosensory deficits, and the syndrome of unilateral spatial neglect. Somatoparaphrenia, most often characterized by a delusion of disownership of left-sided body parts, may however occur without associated anosognosia for motor deficits, and personal neglect. Also somatosensory deficits may not be a core pathological mechanism of somatoparaphrenia, and visual field disorders may be absent. Deficits of proprioception, however, may play a relevant role. Somatoparaphrenia is often brought about by extensive right-sided lesions, but patients with posterior (parietal-temporal), and insular damage are on record, as well as a few patients with subcortical lesions. Possible pathological factors include a deranged representation of the body concerned with ownership, mainly right-hemisphere-based, and deficits of multisensory integration. Finally, the rubber hand illusion, that brings about a bodily misattribution in neurologically unimpaired participants, as somatoparaphrenia does in brain-damaged patients, is briefly discussed.
Vallar
Giuseppe
G
Department of Psychology, University of Milano-Bicocca, Piazza dell'Ateneo Nuovo 1, 20126, Milan, Italy. giuseppe.vallar@unimib.it
Ronchi
Roberta
R
D000377:Agnosia / Q000209:etiology / Q000503:physiopathology / Q000523:psychology*; D001925:Brain Damage, Chronic / Q000503:physiopathology / Q000523:psychology*; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology; D002544:Cerebral Infarction / Q000150:complications / Q000503:physiopathology / Q000523:psychology; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D019965:Neurocognitive Disorders / Q000209:etiology / Q000503:physiopathology / Q000523:psychology*; D010468:Perceptual Disorders / Q000209:etiology / Q000503:physiopathology / Q000523:psychology; D010469:Perceptual Distortion / Q000502:physiology; D012563:Schizophrenia, Paranoid / Q000209:etiology / Q000503:physiopathology / Q000523:psychology*