Anosognosia

Anosognosia
Specialty	Neurology

Anosognosia /æˌnɒsɒgˈnəʊsɪə/ is a condition in which a person who suffers disability seems unaware of the existence of his or her disability. Unlike denial, which is a defense mechanism, anosognosia is rooted in physiology (for example, damage to the frontal or parietal lobe due to illness and disease). This may include unawareness of quite dramatic impairments, such as blindness or paralysis. It was first named by the neurologist Joseph Babinski in 1914. 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%–18% 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, cognitive flexibility, or other major intellectual disturbance. Anosognosia can be selective in that an affected person with multiple impairments may seem unaware of only 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 nothing is wrong with them.

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 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) 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).

Anosognosia may occur as part of 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 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. 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.

Psychiatry

See also: Insight in psychology and 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 a mental illness such as bipolar disorder or psychosis. They do not have the insight to recognize that they suffer from a mental illness. There is evidence that schizophrenic anosognosia may be the result of frontal lobe damage.

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. 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.

One study of voluntary and involuntary inpatients confirmed that committed patients require coercive treatment because they fail to recognize their need for care. Predictably, the patients committed to the hospital had significantly lower measures of insight than the voluntary patients.

Anosognosia is also closely related to other cognitive dysfunctions that may impair the capacity of an individual to continuously participate in treatment. Other research has suggested that attitudes toward treatment can improve after involuntary treatment and that previously committed patients tend later to seek voluntary treatment.

In regard to anosognosia for neurological patients, no long-term treatments exist. As with 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). Another commonly used method is the use of feedback - comparing clients' self-predicted performance with their actual performance on a task in an attempt to improve insight.

See also

• Anosodiaphoria
• Anton–Babinski syndrome
• Brain damage
• Confabulation
• Denial
• Dunning–Kruger effect
• Egosyntonic
• Introspection illusion
• Oliver Sacks
• Unilateral neglect (also known as Hemispatial neglect)
• Vilayanur S. Ramachandran
• Cerebral hypoxia

Further reading

• Amador, Xavier Francisco (2000). I am not sick, I don't need help! Helping the seriously mentally ill accept treatment. A practical guide for families and therapists. Vida Press. ISBN 0-9677189-0-2.
• Berti A; Bottini G; Gandola M; et al. (2005). "Shared cortical anatomy for motor awareness and motor control". Science. 309 (5733): 488–91. doi:10.1126/science.1110625. PMID 16020740. {{cite journal}}: Unknown parameter |author-separator= ignored (help)
• Clare L, Halligan P (2006). "Neuropsychological Rehabilitation.". Pathologies of Awareness: Bridging the Gap between Theory and Practice. Taylor & Francis(Psychology Press). ISBN 9781841698106.
• Lysaker P, Bell M, Milstein R, Bryson G, Beam-Goulet J (1994). "Insight and psychosocial treatment compliance in schizophrenia". Psychiatry. 57 (4): 307–15. PMID 7899525.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• McGlynn S, Schacter DL (1997). "The Neuropsychology of Insight: Impaired Awareness of Deficits in a Psychiatric Context". Psychiatric Annals. 27: 806.
• Pia L, Neppi-Modona M, Ricci R, Berti A (2004). "The anatomy of anosognosia for hemiplegia: a meta-analysis". Cortex. 40 (2): 367–77. doi:10.1016/S0010-9452(08)70131-X. PMID 15156794.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Ramachandran, V. S.; Blakeslee, Sandra (1999). Phantoms in the brain: probing the mysteries of the human mind. New York: Quill. ISBN 0-688-17217-2.{{cite book}}: CS1 maint: multiple names: authors list (link)
• Torrey, E. Fuller (2012). The Insanity Offense. New York: W.W. Norton & Company. pp. 111–122. ISBN 978-0-393-34137-9.
• Vuilleumier P (2004). "Anosognosia: the neurology of beliefs and uncertainties" (PDF). Cortex. 40 (1): 9–17. doi:10.1016/S0010-9452(08)70918-3. PMID 15070000.