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 due to brain injury seems unaware of or denies the existence of his or her handicap. This may include unawareness of quite dramatic impairments, such as blindness or paralysis. It was first named by neurologist Joseph Babinski in 1914, 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.

Neurology

Anosognosia is relatively common following brain injury (e.g. 20–30% in the case of hemiplegia/hemiparesis after stroke), 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. Those diagnosed with dementia of the Alzheimer's type often display this lack of awareness and insist that "There is nothing wrong with me!".

The condition does not seem to be directly related to sensory loss and is thought to be caused by damage to higher level neurocognitive processes which are involved in integrating sensory information with processes which 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) hemisphere of the cerebral cortex in which sufferers seem unable to attend to, or sometimes comprehend, anything on a certain side of their body (usually the left).

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.

On reviewing the applicable literature, one researcher concluded that: "Poor insight in schizophrenia is associated with poorer medication compliance, poorer psychosocial functioning, poorer prognosis, increased relapses and hospitalization and poorer treatment outcomes."cite journal |author=Schwartz RC |title=The relationship between insight, illness and treatment outcome in schizophrenia |journal=Psychiatr Q |volume=69 |issue=1 |pages=1–22 |year=1998 |pmid=9536472 |doi=]

The three kinds of insight that are most vulnerable to severe mental illnesses are the awareness:cite journal |author=Amador XF, Strauss DH, Yale SA, Flaum MM, Endicott J, Gorman JM |title=Assessment of insight in psychosis |journal=Am J Psychiatry |volume=150 |issue=6 |pages=873–9 |year=1993 |pmid=8494061 |doi=]
# that a person is suffering from a mental disorder
# of the effects of medication; and
# of the social consequences of having a mental disorder.

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.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] 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. [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=]

One study of voluntary and involuntary inpatients confirmed that committed patients require coercive treatment because they fail to recognize their need for care.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] 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.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] Other research has suggested that attitudes toward treatment can improve after involuntary treatment and that previously committed patients tend to later seek voluntarily treatment.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=]

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).

ee also

* Brain damage
* Unilateral neglect
* Vilayanur S. Ramachandran
* Oliver Sacks
* Dunning-Kruger Syndrome
* Anton-Babinski syndrome
* Confabulation

Footnotes

Further reading

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