The term agnosia comes from the Greek, means "ignorance" and is used in philosophy as well. In medicine, however, agnosia describes a rare neuropsychological symptom according to which information processing in the brain no longer functions properly. The phenomenon occurs after bi- or unilateral lesions of certain brain regions.
The affected person can indeed perceive all objects around him via his sense organs. However, he is unable to properly assign or name them. The objects are therefore no longer recognized by him, although there are no sensory defects, cognitive disorders or attention deficits. Sigmund Freud introduced the term agnosia in medicine, meaning only the inability to classify the objects seen, even though vision is present.
According to Freud, however, this includes the blindness of the blind and the blindness of the soul. Bark blindness is a blindness due to a functional failure of the visual cortex in the brain despite healthy eyes. The blindness of the soul is characterized by the fact that the objects can be seen but can no longer be assigned. Today, the term agnosia has been extended to failures of all sensory modalities.
The causes of agnosia are the destruction of certain areas of the brain responsible for information processes. These lesions can be caused by strokes, brain injuries, brain tumors, infections of the meninges and brain, or even severe mental illnesses.
If the posterior part of the cerebrum is damaged in the occipital lobe area, visual agnosia can result. That is where the visual information processing takes place. Damage to the posterior temporal lobes often results in acoustic agnosia. When the parietal lobe is damaged, autotopagnosia often occurs. Here, the affected patient can no longer localize skin stimuli on his own body.
There are several forms of agnosia that the doctor can easily assign. The type of agnosia already gives the doctor indications of which brain regions are affected. For this purpose, he carries out various tests, which relate to specific sensory areas. Generally there is a division into visual, acoustic, tactile or spatial agnosia. There are also the autotopagnosia and the anosognosia.
The visual agnosia can in turn be subdivided into different subforms. Thus, the so-called prosopagnosia is a disorder of facial perception. The patient does not recognize known persons on the face. Detection takes place, for example, via the voice or the gear. Furthermore, this group also includes apperceptive agnosia. Although the affected person can perceive individual elements, he can not put them together to form a complete object.
In the context of associative agnosia, the patient recognizes the entire object in form and shape, but can not do anything with its function. In the case of color diagnosis, the colors can no longer be recognized. Acoustic agnosia is characterized by the fact that the person concerned hears sounds, but can not put them together to words or sentences. The inability to orient oneself in space is called spatial agnosia. In tactile agnosia, sensed objects can not be assigned.
The non-recognition of functional failures of one's own body parts or organs is called anosognosia. Here, the patient perceives the failed body parts as functional and would like to use them accordingly. This can lead to falls.
Agnosia can be the cause of various complications. Depending on the severity and cause of agnosia, there are severe motor impairments and dysfunctions of the sensory organs. The sense of balance, for example, is greatly disturbed by the neuropsychological symptom, which can lead to falls and similar injuries. The eyes and ears are affected as well and only work for people with disabilities to a limited extent or not at all. The complications that follow can aggravate the main symptoms of agnosia.
In addition, the intellectual capacity is usually severely limited and can only partially be restored by occupational therapy. Further complications occur in agnosia mainly through secondary damage such as auto-autografting. This makes it impossible for those affected to localize skin irritation or injury to their own body, which often leads to an intensification of existing diseases. Not least, the emotional state of those affected is a risk factor.
An agnosia can lead to severe mental and physical disabilities and thus burden the patient enormously psychologically. Complications are rare in the actual therapy. Often it comes to lasting damage, but the occupational therapy is without great risks for those affected. Only with the medicamentous treatment, for example with the treatment of psychological consequence symptoms necessary, further complications can occur in some cases.
As soon as relatives or the person concerned notices that he or she is suffering from a failure to recognize objects or persons, a doctor should be consulted immediately and as quickly as possible. Since the sensory organs are usually not damaged, there is a risk that, therefore, perhaps initial symptoms are not immediately recognized or the hope that the disorder has disappeared shortly.
In case of agnosia, eyes and ears continue to function. Nevertheless, the non-recognition of objects is an elementary disturbance of perception and this is very serious. The insignificance of the visual impressions in a sick person indicates brain damage, which should be investigated as soon as possible. In addition, there is an increased risk of coping with everyday life for the person suffering further damage.
If the malfunction causes a car to no longer be recognized, the passage over the road is classified as life-threatening. Only through an intensive medical examination, the agnosia can be diagnosed and appropriate medical measures are initiated. Soul blindness is a lesion in the brain. Therefore, the non-recognition of objects is to be understood as an immediate warning signal. Unfortunately, spontaneous healing or the presence of temporary effects of restriction is not expected.
There is no specific treatment for agnosia. If a lesion has occurred in a certain area of the brain, for example through a stroke, it may come to an improvement on its own after some time. However, this depends on the size and location of the injury and the age of the patient. After the first three months, most of the recovery is done. Even after that, many processes still take place, which weaken the failure.
However, permanent disability must be assumed in most cases. The physician can only take compensatory measures to overcome the failures. In the context of occupational therapy, for example, an attempt is made to compensate for the corresponding agnosia as best as possible through other existing functions. During occupational therapy, the patient can learn to use other features to recognize people and objects.
For example, in the case of agnosia, the patient does not recognize the face of a person known to him. However, to identify this person, the person concerned can resort to other characteristics such as voice, posture or gait. The learning process may be so successful that the missing face recognition no longer plays any role and may even not be noticed.
Occupational therapy can of course be used in all forms of agnosia. It exploits the fact that as a rule only selective failures occur in the information processing system of the brain.
As a rule, the patient's perception of the agosnie is severely disturbed. This mainly affects the recognition of faces of different people. Patients then try to associate people with their voice or gait. The Agosnie, however, can also affect other areas of life. These include, for example, colors or shapes that can not be recognized either. This leads to a severe restriction of everyday life in the patients. Thus, by the Agosnie some professions can not be exercised.
Unfortunately, there is no treatment for the Agosnie. However, exercises can be performed that compensate for the weaknesses and replace them with other possibilities of perception. Agosnie therefore does not result in a reduced life expectancy for most people. For the treatment above all methods from the Ergotherapie or the Logopädie are used.
In complicated cases, certain organs can fail completely. These include, for example, the ears or the eyes. This can lead to a very severe limitation of everyday life for the patient. These patients are then dependent on the help of other people.
An agnosia can not be prevented. There are innate and acquired forms. The congenital forms are often genetic diseases or prenatal developmental disorders. The acquired forms are caused by diseases such as strokes or other brain organic disorders. For all forms of agnosia there are no prophylactic measures.
Agnosia is not a common disease symptom, but a very big problem for those who suffer from it. The terms "deafness of the soul" and "blindness of the soul" used in German indicate how multifaceted and serious the disorder of hearing, sight or tactile ability can be.
Because the symptom occurs so individually, it is absolutely necessary in the treatment - especially in self-help - to proceed patient-specific. The agnosia is usually incurable, but by special training forms, the impairments can be more or less compensate. For example, in the case of prosopagnosia, the goal is to enable patients to identify people by means of identifying features other than the face (posture, gait, voice, clothing, hairstyle, etc.). Sometimes it seems simple-looking measures that help - such as writing and computational exercises. Which exercises should be performed should be discussed with the therapist or the doctor. Generally speaking or occupational therapies are essential in the treatment.
Through learning processes and memory formation, new neurons and synapses are created in the brain during targeted exercises, which can improve performance. Much depends on the treatment of the circle of friends and the family. It is advisable to ensure the social integration of the person concerned, to reduce his risk of injury in everyday life and to give him peace of mind through a safe manner.Tags: