Somatoparaphrenia

Somatoparaphrenia
SpecialtyPsychiatry

Somatoparaphrenia is a type of monothematic delusion where one denies ownership of a limb or an entire side of one's body. Even if provided with undeniable proof that the limb belongs to and is attached to their own body, the patient produces elaborate confabulations about whose limb it really is or how the limb ended up on their body.[1][2] In some cases, delusions become so elaborate that a limb may be treated and cared for as if it were a separate being.[1]

Somatoparaphrenia differs from a similar disorder, asomatognosia, which is characterized as loss of recognition of half of the body or a limb, possibly due to paralysis or unilateral neglect.[3] For example, asomatognosic patients may mistake their arm for the doctor's. However, they can be shown their limb and this error is temporarily corrected.[1]

Somatoparaphrenia has been reported to occur predominantly in the left arm of one's body,[4] and it is often accompanied by left-sided paralysis and anosognosia (denial or lack of awareness) of the paralysis. The link between somatoparaphrenia and paralysis has been documented in many clinical cases,[5] and while the question arises as to whether paralysis is necessary for somatoparaphrenia to occur, it has been confirmed that anosognosia is not necessary, since cases of somatoparaphrenia and paralysis with no anosognosia have been documented.[6]

  1. ^ a b c Feinberg T.; Venneri A.; Simone A.M.; et al. (2010). "The neuroanatomy of asomatognosia and somatoparaphrenia". Journal of Neurology, Neurosurgery & Psychiatry. 81 (3): 276–281. doi:10.1136/jnnp.2009.188946. PMID 19778911. S2CID 4931879.
  2. ^ Bottini G.; Bisiach E.; Sterzi R.; Vallar G. (2002). "Feeling touches in someone else's hand". NeuroReport. 13 (2): 249–252. doi:10.1097/00001756-200202110-00015. PMID 11893919. S2CID 32287566.
  3. ^ Vallar G., Ronchi R. (2009). "Somatoparaphrenia: a body delusion. A review of the neuropsychological literature". Experimental Brain Research. 192 (3): 533–551. doi:10.1007/s00221-008-1562-y. PMID 18813916. S2CID 206924931.
  4. ^ Coltheart M (2005). "Delusional belief". Australian Journal of Psychology. 57 (2): 72. doi:10.1080/00049530500125082.
  5. ^ Vallar G., Ronchi R. (2009). "Somatoparaphrenia: A body delusion. A review of the neuropsychological literature". Experimental Brain Research. 192 (3): 533–51. doi:10.1007/s00221-008-1562-y. PMID 18813916. S2CID 206924931.
  6. ^ Invernizzi P, Gandola M, Romano D, Zapparoli L, Bottini G, Paulesu E (2013). "What is mine? Behavioral and anatomical dissociations between somatoparaphrenia and anosognosia for hemiplegia". Behav Neurol. 26 (1–2): 139–50. doi:10.1155/2013/548467. PMC 5213125. PMID 22713395.