Anosognosia (from the Greek : a, privative prefix + nosos, disease + gnosis, knowledge: “ignorance of the disease”), is the pathological situation referred to patients with neurological (cognitive) problems who have no perception of their neurological functional deficits .
It is a denial of the neurological pathology itself: The patient does not admit that something is really wrong with him being the cause of this deficit an organic damage that really is preventing such perception.
History
It was Babinski in 1914 and, later, in 1918 , who made a description of patients who presented left hemiplegia and who were not aware that said part of the body was motionless and called this “anosognosia.” As stated by Martínez Rodríguez ( 2007 ), taken from Babinski : “It is as if the subject was completely disinterested in his paralyzed arm, as if he had an inability to fix his attention on it.”
Prior to this designation of Babinski’s anosognosia , Beige ( 1905 ) used the expression “functional motor amnesia” to refer to this phenomenon. According to Meige (taken from André JM et al., 2004 ): “However (speaking of hemiplegia) (…) muscles, originally inert, little by little recover all or part of their contractility, but the patient does not use of them. Numerous movements that were impossible in the initial stages of the disease are subsequently possible, but are not carried out. The hemiplegic does not know them. He has forgotten about them ”. Actually, reading Meige, he gives the impression of speaking more of an apraxic picture – which he refers to as motor amnesia – than of a true anosognosia.
Subsequently, in the mid-nineties, many cases of anosognosia have been described and an attempt has been made to explain them from different disciplines and associated with diverse and not only motor conditions ( Sandifer , 1946 ; Cobss , 1947 ; Weinstein , 1950 ; Oppenheimer , 1951 ).
Definition
According to the RAE, anosognosia is a term of Psychology that means “disease that consists of not being aware of the notorious evil that one suffers”. This definition introduces a term (disease) that differentiates it from other “unawareness of the notorious evil that one suffers.” In addition, it refers to something that is main in the diagnosis of anosognosia: it is the lack of awareness of one’s own evil and not of the evil that may be causing others.
According to Prigatano ( 2005 ) “anosognosia is defined as the clinical phenomenon by which a patient with brain dysfunction does not seem to be aware of the deterioration of neurological or neuropsychological function, which is evident to the doctor and to other people. Lack of awareness seems specific to one’s own deficits and cannot be explained by hyperarousal or generalized cognitive impairment ”.
In the definition of Prigatano there are already some different data:
• there is brain dysfunction,
• it is a clinical phenomenon and not a unitary entity such as a disease,
• is given only for own alterations;
• is not explained by another concomitant alteration.
This definition refers to the “inability to realize the disability” (perhaps it would be better to say “the disorder of not realizing that there is a clear dysfunction”) and, from my point of view, a concept is isolated clear: there is a fault in the deficit consciousness systems . Obviously, this would force us to enter what consciousness and consciousness mean, which would be part of a separate chapter in neurobiology, referring the reader to advanced classical texts such as that of Koch ( 2004 ) or that of Edelman and Tononi ( 2002 ).
For Zarranz ( 2001 ), anosognosia is “the inability of the patient to recognize his disease and can refer to motor defects, but also language, memory or visual defects”.
The differentiation between anosognosia and other forms of ” deficit unawareness ” is not clear. At least they are not sufficiently delimited. By the definitions that we find from the classical authors and others, anosognosia would be mainly a not realizing, a not being aware of an evident deficit. Are there not patients with psychiatric illnesses who are unaware of their own deficits? Are you not a patient with a psychotic break not aware of your deficit? On the other hand, aren’t patients with Borderline Personality Disorders, for example, unaware of their obvious impulsiveness or lies? Indeed, the answer would be yes, although the deficits are not as obvious as paralysis or blindness, that they can be objectified.
I understand that entering into these particularities is certainly not only risky but would be typical of a detailed study on anosognosia, an objective that escapes this chapter. However, I cannot help pointing out the similarities between the lack of awareness of the deficit of people with certain psychiatric disorders. In addition, as we will see later, clear anosognosia has been reported in specific psychiatric conditions such as Schizophrenia or Personality Disorders.
According to Orfei MD et al. ( 2007 ), “anosognosia is the lack of awareness or the underestimation of a specific deficit in sensory, perceptual, motor, affective or cognitive functioning due to a brain injury”. Obviously, this definition is much broader than the previous ones.
Therefore, taking these and other definitions into consideration, anosognosia could be defined as a disorder of brain origin, the cause of which may or may not be known, which may be derived from an alteration of brain structure and / or function, and which It consists, mainly, in the non-awareness of an alteration of some bodily function (physical, neurocognitive or psychological) that is very evident for people who know the patient and also for other people who can compare what happens with reality, not being explainable by a negation mechanism.
Diagnostic criteria and classification of anosognosia
To date, there are no specific diagnostic criteria for the diagnosis of anosognosia. Some consider it a disease, while others consider it a symptom and others a syndrome. The most exact definition of anosognosia would fit into the category of sign or symptom within a general picture (just as joint pain is from the flu).
The only diagnostic criteria proposed for the diagnosis of anosognosia are proposed by the Consortium of Clinical Neuropsychology ( 2010 ):
- A. Alteration of consciousness of suffering from a physical, neurocognitive and / or psychological deficit, or suffering from a disease.
- B. This alteration is mainly, in the form of denial of what happens to it, with several different types of expressions:
i) To the question “What’s wrong?” the patient responds “nothing” or anything that has nothing to do with what is being brought to the consultation and that makes the patient, in a certain way, not situated in the context. For example, when asked “then why do you come for a consultation?” the patient responds “I don’t know; maybe it’s because of the knee pain I have ”.
ii) To a direct question such as “isn’t your memory bad?”, the patient will respond with “I forget things like everyone else” or “not at all: I have a better memory than my wife”.
iii) Faced with evidence of his failures in the examination, the patient will say something like “I have never been good at this type of thing” (eg, in an exploration of memory functions).
iv) Faced with the evidence of their personality dysfunction (obvious lies, manipulations, etc.), there will always be the deepest conviction that others (society, etc.) are to blame for what is happening in the manner of what is happening. indicated by Bialer ( 1961 ) and Rotter ( 1966 ) as precursors of the theories of “locus of control” and, later, studied by Lazarus or Bandura ( 1999 ), among others.
- C. Evidence of said deficits through evaluation instruments (whether validated or not) aimed at the fundamentals of said deficit. An example of this would be the motor examination of a patient with hemiplegia or the verification by means of executive function tests of the alteration of these functions.
- D. Evidence for known persons of said alteration, verified with tests of daily life.
- E. Negative influence on their daily life, reducing their independence and causing problems and difficulties.
- F. This alteration does not occur in the context of confusional states or altered states of consciousness, nor does it occur due to severe aphasia (Global or Wernicke) *.
- Anosognosia could occur in severe aphasia, but the signs should be so obvious that this point can be avoided.
Lack of awareness of the deficit is part of many clinical pictures that are “not” neurological according to the vast majority of those treated.
Anosognosia could be classified according to the parameters defined by the doctor for its diagnosis.
Clinical pictures presenting with anosognosia
Anosognosia associated with hemiplegia
The typical pictures that cause hemiplegia tend to be mostly vascular and, specifically, in frontal-parietal cortical areas. Normally, anosognosia is more associated with left than right hemiplegic conditions, although it is a conclusion that sometimes does not take into account that patients with right hemiplegia tend to have severe verbal comprehension disorders in a high number of cases , which makes it very difficult to know the proportion in which they are aware of both aphasia and hemiplegia. In any case, this is not an easy question and the anosognosia of aphasia or hemiplegia in a severe aphasic patient is still a detective work that is mainly based on indirect signs.
The lesion predominance is always more marked in patients injured in the right hemisphere than in the left hemisphere.
Patients who present anosognosia of their hemiplegia are usually, in a certain way, “indifferent” to its affectation and are often confused with a person who has a denial mechanism. The patient says that he does not get out of bed because he is tired, because he does not feel like it or because of anything. It is impossible to make him see his paralysis and, if the correct data is shown, the patient always leads to some reason why he does not want to move.
They are “delusional” patients: they are incapable of being reduced by the evidence. Indeed, anosognosia, as noted, is a broad field of study in schizophrenia.
Anosognosia associated with cortical blindness
Associated cortical blindness has been described as well as, obviously, in lesions involving primary and secondary visual areas, mainly due to cerebral infarcts.
Anosognosia associated with aphasia
As previously stated, it is difficult to reveal the anosognosia associated with right hemiplegia.
The vast majority of anosognosia pictures described in aphasic patients have been in so-called sensitive aphasias, mainly in Wernicke-type aphasias (Lazar et al., 2000 ). The cadres usually study with a lack of knowledge of the linguistic deficit when they preferably study with multiple paraphasias and jargon.
Anosognosia associated with hemiasomatognosia
Hemiasomatognosia or unilateral bodily negligence consists of the lack of recognition of the hemibody itself. Anosognosia of the defect is usually associated in these cases (Peña-Casanova, 1994 ). It can be conscious or unconscious, depending on whether or not awareness of the existence of the hemibody is lost. Conscious hemiasomatognosia is usually secondary to paroxysmal phenomena, either epileptic or migraine, while the unconscious is typical of hemispheric lesions, which we will comment in more detail. A wide variety of disorders of the body’s own consciousness have been established due to involvement of the right temporal lobe, citing up to sixteen different forms (Ardila, 1992 ).
The perception of one’s own body involves many variables to consider and should not be confused or compared with the perception of extrapersonal space. There are pictures of spatial heminegligence that also include corporal hemineglect, and then it is called hemiinattention syndrome, but the visuospatial heminegligent patient may be aware of half of his own body and spatial heminegligence does not necessarily have to be associated with anosognosia of hemineglect.
There are very few studies that have addressed the possibility that personal hemineglect is dissociated from the hemineglect of the surrounding space (Bisiach et al., 1986 ).
Patients with intrinsic alterations of the body scheme (both phantom limb and personal hemineglect) retain the second system (general, semantic and topographic knowledge of the human body) unscathed, as demonstrated by successfully performing tasks aimed at identifying and locating parts of the body. own body or a model (Guariglia et al., 1992). Right brain injured patients with personal hemineglect have been described, in whom added difficulties are seen in assembling dolls or identifying the laterality of figures with rotated hands. This alteration may, in principle, imply an impairment of bodily knowledge, but the extent of the brain lesions raises doubts whether it is rather an alteration resulting from its visuo-constructive difficulties (Coslett et al.,1989 ).
Anosognosia associated with amnesia
When we talk about anosognosia associated with amnesia, we mainly talk about Korsakoff syndrome , although other amnesias also present a high degree of anosognosia, such as those associated with ruptures of aneurysms of the anterior communicating artery or even amnesias due to bilateral lesion of the CA1 area of the hippocampus (Salmon et al., 2006 ).
Anosognosia associated with left visuospatial heminegligence
Left visuospatial hemineglect can present with anosognosia in many cases. The patients not only present an inability to attend to the left hemifield but also present a deficit of consciousness regarding said deficit . Thus, patients routinely stumble upon objects in their left hemifield and downplay it by saying things like, “Who put this here?”
Anosognosia exploration
Although the diagnosis of anosognosia is fundamentally clinical, there are some instruments that can be used for its diagnosis.
There are two instruments proposed for the diagnosis of anosognosia, it is a questionnaire where patients are asked to assess their motor skills (or linguistics, depending on which one). Each question is illustrated with a simple drawing and a 4-point visual-analog scale is used for motor or language problems, where 0 indicates that “no difficulty in performing the task” and 3 indicates “great difficulties or impossibility. to carry out the task. ” Patients can indicate the response through a verbal response or through motor response, pointing to the picture.
Another approach was that of Nimmo-Smith et al. ( 2005 ) based on questions about bimanual or unilateral tasks, the bimanual ones being superior in specificity and sensitivity. On the other hand, the Catherine Bergego Scale (Azouvi et al., ND; Bergego et al., 1995 ) has also been tested for anosognosia, including certain sections that shed light in this regard.
The indications of Bisiach et al. ( 1986 ) escalated, through specific questions, in the following degrees of anosognosia:
• Grade 0: No anosognosia. The patient explains his disorder;
• Grade 1: The disorder is reported only following a specific question about deficits;
• Grade 2: the disorder is recognized only after clearly demonstrating its involvement;
• Grade 3: The disorder is not recognized in any of the possible ways.
Although there are other scales, these are perhaps the main ones used in patients with anosognosia.
Treatment of anosognosia
There is no type A evidence of any treatment for anosognosia that has been shown to be effective.
Some proposals such as those of Bottini et al. ( 1995 ) or Vallar et al. ( 1990 ) on vestibular stimulation and the relationship with some aspects of deficit awareness have only grade E evidence.