View source for Anosognosia

{{Infobox Symptom
| Name           = Anosognosia 
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| ICD10          = {{ICD10|R|41|8|r|40}}
| ICD9           = {{ICD9|780.9}}
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'''Anosognosia''' is a condition in which a person who suffers [[disability]] seems unaware of or denies the existence of his or her disability. This may include unawareness of quite dramatic impairments, such as [[blindness]] or [[paralysis]]. It was first named by [[neurologist]] [[Joseph Babinski]] in 1914,<ref name=Prigatano>{{cite book |author=Prigatano, George P.; Schacter, Daniel L |title=Awareness of deficit after brain injury: clinical and theoretical issues |publisher=Oxford University Press |location=Oxford [Oxfordshire] |year=1991 |pages=53–55 |isbn=0-19-505941-7 |url=http://books.google.com/?id=xze89PCLaWMC&lpg=PP1&pg=PA53}}</ref> although relatively little has been discovered about the cause of the condition since its initial identification. The word comes from the Greek words ''"nosos"'' disease and ''"gnosis"'' knowledge (an- / a- is a negative prefix).

==Causes==
Anosognosia is relatively common following brain injury (e.g. 10%&ndash;18% in the case of [[hemiplegia]]/[[hemiparesis]] after [[stroke]]<ref>{{Cite journal |url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1739568 |title=Incidence and diagnosis of anosognosia for hemiparesis revisited |date= 2005 March |author=B Baier and H Karnath |journal=J Neurol Neurosurg Psychiatry |volume=76 |issue=3 |pages=358–361 |doi=10.1136/jnnp.2004.036731 |pmid=15716526 |pmc=1739568 |postscript=<!--None--> }}</ref>), but can appear to occur in conjunction with virtually any neurological impairment. However, it is not related to global mental confusion (see [[delirium]]), cognitive flexibility, or other major intellectual disturbance. Anosognosia can be selective in that an affected person with multiple impairments may only seem unaware of one handicap, while appearing to be fully aware of any others.<ref>{{cite book |url= |title=Brain fiction: self-deception and the riddle of confabulation |first= William |last=Hirstein |pages=148 |publisher=MIT Press |year=2004 |isbn=0262083388}}</ref>  Those diagnosed with [[Alzheimer's disease|dementia of the Alzheimer's type]] often display this lack of awareness and insist that there is nothing wrong with them.

The condition does not seem to be directly related to [[senses|sensory]] loss and is thought to be caused by damage to higher level [[neurocognitive]] processes that are involved in integrating sensory information with processes that support spatial or bodily representations (including the [[somatosensory]] system).  Anosognosia is thought to be related to [[unilateral neglect]], a condition often found after damage to the non-dominant (usually the right<ref>{{Cite journal |url=http://cat.inist.fr/?aModele=afficheN&cpsidt=3452304 |title=Dissociation of anosognosia for hemiplegia and aphasia during left-hemisphere anesthesia |author=Breier J, Adair J C, Gold M, Fennell E, Gilmore R, Heilman K |journal=Neurology |volume=45 |issue=1 |date= April 20, 1995 |pages=65 |pmid=7824138 |postscript=<!--None--> }}</ref>) hemisphere of the [[cerebral cortex]] in which sufferers seem unable to attend to, or sometimes comprehend, anything on a certain side of their body<ref>{{Cite journal |url=http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1692420 |title=Possible mechanisms of anosognosia: a defect in self-awareness |author=K M Heilman, A M Barrett, and J C Adair |date=1998-11-29 |journal=Philosophical Transactions of the Royal Society B: Biological Sciences |volume=353 |issue=1377 |pages=1903–1909 |pmid=9854262 |doi=10.1098/rstb.1998.0342 |pmc=1692420 |postscript=<!--None--> }}</ref> (usually the left).

Anosognosia may occur as part of [[receptive aphasia|Wernicke's aphasia]], a language disorder that causes poor comprehension of speech and the production of fluent but incomprehensible sentences. A patient with Wernicke's aphasia cannot correct his own [[Phonetics|phonetic]] errors and shows "anger and disappointment with the person with whom he is speaking because that person fails to understand him." This may be a result of brain damage to the posterior portion of the [[superior temporal gyrus]], believed to contain representations of word sounds. With those representations destroyed, patients with Wernicke's aphasia are unable to monitor their mistakes.<ref name=Prigatano /> Other patients with Wernicke's aphasia are fully aware of their condition and speech inhibitions, but cannot monitor their condition, which is not the same as anosognosia and therefore cannot explain the occurrence of neologistic jargon. <ref>Andrew W. Ellis, Diane Miller, Gillian Sin, Wernicke's aphasia and normal language processing: A case study in cognitive neuropsychology, Cognition, Volume 15, Issues 1-3, December 1983, Pages 111-144, ISSN 0010-0277, DOI: 10.1016/0010-0277(83)90036-7.
(http://www.sciencedirect.com/science/article/B6T24-45Y6PCW-W/2/7282cf795758c88a918bd5a26466b2c5)</ref>

==Psychiatry==
Although largely used to describe unawareness of impairment after brain injury or stroke, the term 'anosognosia' is occasionally used to describe the lack of insight shown by some people who suffer from [[psychosis]], and who therefore do not have the insight to recognize that they suffer from a mental illness.  There is also evidence that schizophrenic anosognosia may be the result of frontal lobe damage.<ref>{{cite journal |author=Pia L, Tamietto M |title=Unawareness in schizophrenia: neuropsychological and neuroanatomical findings |journal=Psychiatry Clin. Neurosci. |volume=60 |issue=5 |pages=531–7 |year=2006 |pmid=16958934 |doi=10.1111/j.1440-1819.2006.01576.x }}</ref>

==Treatment==
In regard to psychiatric patients, empirical studies verify that, for individuals with severe mental illnesses, lack of awareness of illness is significantly associated with both medication non-compliance and re-hospitalization.<ref name="Insight&Psychosis">{{cite book |author=McEvoy J |chapter=The Relationship Between Insight in Psychosis and Compliance With Medications |pages=299 |title=Insight and Psychosis |editor=Xavier F. Amador & Anthony S. David eds |year=1998 |url=http://books.google.com/?id=4ZAMmCJUHAAC&pg=PA289&lpg=PA289 |publisher=Oxford University Press US |isbn=9780195084979 }}</ref> Fifteen percent of individuals with severe mental illnesses who refuse to take medication voluntarily under any circumstances may require some form of coercion to remain compliant because of anosognosia.<ref>{{cite book |author=David, Anthony S.; Amador, Xavier Francisco |title=Insight and psychosis: awareness of illness in schizophrenia and related disorders |publisher=Oxford University Press |location=Oxford [Oxfordshire] |year=2004 |pages=293 |isbn=0-19-852568-0 |oclc= |doi=}}</ref>

One study of voluntary and involuntary inpatients confirmed that committed patients require coercive treatment because they fail to recognize their need for care.<ref name="pmid2564330">{{cite journal |author=McEvoy JP, Applebaum PS, Apperson LJ, Geller JL, Freter S |title=Why must some schizophrenic patients be involuntarily committed? The role of insight |journal=Compr Psychiatry |volume=30 |issue=1 |pages=13–7 |year=1989 |pmid=2564330 |doi=10.1016/0010-440X(89)90113-2}}</ref> Predictably, the patients committed to the hospital had significantly lower measures of insight than the voluntary patients.

Anosognosia is also intimately related to other cognitive dysfunctions that may impair the capacity to continuously participate in treatment.<ref name="pmid2564330"/> Other research has suggested that attitudes toward treatment can improve after involuntary treatment and that previously committed patients tend to later seek voluntary treatment.<ref name="pmid6838317">{{cite journal |author=Kane JM, Quitkin F, Rifkin A, Wegner J, Rosenberg G, Borenstein M |title=Attitudinal changes of involuntarily committed patients following treatment |journal=Arch. Gen. Psychiatry |volume=40 |issue=4 |pages=374–7 |year=1983 |pmid=6838317 |doi=}}</ref>

In regard to anosognosia for neurological patients, there are currently no long-term treatments for anosognosia, although, like [[unilateral neglect]], [[caloric reflex testing]] (squirting ice cold water into the left ear) is known to temporarily ameliorate unawareness of impairment. It is not entirely clear how this works, although it is thought that the unconscious shift of [[attention]] or focus caused by the intense stimulation of the vestibular system temporarily influences awareness. Most cases of anosognosia appear to simply disappear over time, while other cases can last indefinitely. Normally, long-term cases are treated with cognitive therapy to train the patient to adjust for their inoperable limbs (though it is believed that these patients still are not "aware" of their disability).

==See also==
*[[Anosodiaphoria]]
*[[Anton–Babinski syndrome]]
*[[Brain damage]]
*[[Confabulation]]
*[[Dunning–Kruger effect]]
*[[Introspection illusion]]
*[[Oliver Sacks]]
*[[Unilateral neglect]] (also known as Hemispatial neglect)
*[[Vilayanur S. Ramachandran]]

==Footnotes==
{{reflist|2}}

==Further reading==
{{refbegin}}
*{{cite book |author=Amador, Xavier Francisco |title=I am not sick, I don't need help!: helping the seriously mentally ill accept treatment: a practical guide for: families and therapists |publisher=Vida Press |location= |year=2000 |pages= |isbn=0-9677189-0-2 |oclc= |url=}}
*{{cite journal |author=Berti A, Bottini G, Gandola M, ''et al.'' |title=Shared cortical anatomy for motor awareness and motor control |journal=Science |volume=309 |issue=5733 |pages=488–91 |year=2005 |pmid=16020740 |doi=10.1126/science.1110625}}
*{{cite book |author=Clare L, Halligan P |title=Pathologies of Awareness: Bridging the Gap between Theory and Practice |chapter=Neuropsychological Rehabilitation. |year=2006 |publisher= Taylor & Francis(Psychology Press) |isbn=9781841698106}}
*{{cite journal |author=Lysaker P, Bell M, Milstein R, Bryson G, Beam-Goulet J |title=Insight and psychosocial treatment compliance in schizophrenia |journal=Psychiatry |volume=57 |issue=4 |pages=307–15 |year=1994 |pmid=7899525 |doi=}}
*{{cite journal |author=McGlynn S, Schacter DL |title=The Neuropsychology of Insight: Impaired Awareness of Deficits in a Psychiatric Context |journal=Psychiatric Annals |volume=27 |issue= |pages=806 |year=1997 |pmid= |doi=}}
*{{cite journal |author=Pia L, Neppi-Modona M, Ricci R, Berti A |title=The anatomy of anosognosia for hemiplegia: a meta-analysis |journal=Cortex |volume=40 |issue=2 |pages=367–77 |year=2004 |pmid=15156794|doi=10.1016/S0010-9452(08)70131-X}}
*{{cite book |author=Ramachandran, V. S.; Blakeslee, Sandra |title=Phantoms in the brain: probing the mysteries of the human mind |publisher=Quill |location=New York |year=1999 |pages= |isbn=0-688-17217-2 |oclc= |doi=}}
*{{cite journal |author=Vuilleumier P |title=Anosognosia: the neurology of beliefs and uncertainties |journal=Cortex |volume=40 |issue=1 |pages=9–17 |year=2004 |pmid=15070000 |doi=10.1016/S0010-9452(08)70918-3|url=http://labnic.unige.ch/nic/papers/PV_CX2004.pdf |format=PDF}}
{{refend}}

[[Category:Neurological disorders]]
[[Category:Symptoms]]
[[Category:Disability]]

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