Anosognosia

From Psy3242

Anosognosia comes from the Greek roots “nosos” meaning disease and “gnosis” knowledge, with the prefix “a” meaning without. Anosognosia is the ignorance of the presence of disease. This condition was originally interchangeable in the medical field with denial. However, denial is an unconscious defense mechanism characterized by refusal to acknowledge painful realities, thoughts, or feelings. In 1914 Babinski coined the term anosognosia to describe patients with hemiplegia who were not aware of their illness. It is differentiated from denial because it is an unawareness of a neurological deficit and does not appear to be a defense mechanism.

Early in research on the condition, Weinstein and Kahn (1955), believed that there may be individual types of anosognosia. Their research was not able to isolate a neurological function or brain area that was specifically associated with anosognosia. Even so, there are a variety of syndromes associated with anosognosia that apply to a variety of different neurological problems. However, this condition is most closely associated with paralysis occurring in patients with non-dominant parietal lobe lesions, who deny presence of hemiparesis. It also occurs in people who become blind, in Anton's syndrome; or who which lose some other sensory experience as well as in mentally ill people.

Anosognosia is most commonly related to the denial of paralysis in people who recently suffered strokes. Approximately 20-30% of people with hemiplegia or hemiparesis after strokes also have symptoms of anosognosia. Some research has found as high as 58% of right hemisphere stroke patients denied hemiplegia or acknowledge weakness in their left arm. Likewise, some researchers, Xavier Amador specifically, has suggested that a form of anosognosia affects many schizophrenic and bipolar patients. He believes that nearly half of people with these disorders do not get treatment because they do not acknowledge that they are ill. Even patients who are diagnosed resist believing they are ill and instead fabricate illogical explanations for their symptoms and behaviors.

From further research it appears that anosognosia patients differ widely when confronted about their condition. In milder cases patients show some acknowledgement of their illness and became agitated when told about their condition. Other patients are completely unaware and are surprised when they cannot perform tasks (Prigatano and Koloff). Treatment for people with anosognosia is difficult. Although many people recover relatively quickly from this condition, it does remain permanent in other instances. In cases of strong anosognosia in particular, patients may resist treatment all together.