Agnosia - types of the disease , causes, symptoms , treatment


1. reasons agnosia

2. Types agnosia

3. Diagnostics

4. Treatment

agnosia - a pathological condition inwhere there is a violation of the processes of perception (auditory, visual, tactile) while maintaining the functions of consciousness and senses.In the state of agnosia person is not able to identify an object, using a specific sensory organ.Most often, agnosia occurs in adults and children aged 10 to 17 years.

reasons agnosia

main cause agnosia is damage to the brain.It can be caused by heart attacks, various traumas, tumors, and degeneration of the brain regions that are integrating perception, memory and identification (recognition) that is responsible for the synthesis and analysis of information.Agnosia type depends on the location of the lesion.

Types agnosia

The disease has three main types: this visual agnosia, auditory agnosia, and tactile agnosia.In addition, there are several other less common types of the disease (spatial agnosia and other distur

bances of perception).

When visual agnosia lesions localized in the occipital lobe of the brain.This type of agnosia characterized by the inability of the patient to recognize objects and images, despite the fact that he had saved enough for that visual acuity.Visual agnosia can be expressed in different ways and to manifest itself in the form of the following disorders:

- objective agnosia (loss convexital surface of the left side of the occipital region): inability to recognize different objects, in which the patient can only describe the individual features of the object, but can not say,that of the subject in front of him;

- color agnosia (failure of the left occipital region of the dominant hemisphere): the inability to classify colors to identify the same colors and shades, to correlate a particular color to a particular subject;

- visual agnosia, which is manifested in the weakness of optical concepts (bilateral involvement occipital-parietal region): the inability to imagine an object and describe it (called the size, color, shape, etc.);

- agnosia for faces or prosopagnosia (defeat bottom of the occipital region of the right hemisphere): violation of facial recognition process while maintaining the ability to distinguish objects and images, which in severe cases can be characterized by the inability of the patient to recognize his own face in a mirror;

- Simultaneous agnosia (loss front of the dominant occipital lobe): a sharp decrease in the number of simultaneously perceived objects, in which the patient is often able to see only one thing;

- syndrome Balint, or visual agnosia caused by optical-motor impairments (bilateral involvement occipital-parietal region): the inability to direct gaze in the right direction, focusing it on a particular object, which is especially pronounced may occur when reading - the patient may not normally readsince it is very difficult to switch from one word to another.

auditory agnosia arise in lesions of the temporal cortex of the right hemisphere.This type of agnosia characterized by the inability of the patient to recognize sounds and speech, while the function of the auditory analyzer is not broken.In the category of auditory agnosia are following violations:

- simple auditory agnosia, in which the patient can not recognize a simple, familiar sounds (sound of the rain, rustling paper, knocking, creaking doors, etc.);

- audio-verbal agnosia - the inability to distinguish between speech (for the person suffering from this type of auditory agnosia, native speech is represented as a set of unfamiliar sounds);

- tone auditory agnosia - the patient can not capture the tone, timbre, emotional speech, but he retained the ability to properly perceive speech and recognize grammatical structures correctly.

tactile agnosia If the patient is not possible to identify objects by touch.One type of haptic agnosia - inability to recognize parts of the patient's own body, and to assess their location relative to each other.This type of tactile agnosia called somatoagnoziey.Tactile agnosia, in which broken items by touch recognition process is called astereognosis.

There are also spatial agnosia, which are expressed in the form of a variety of disorders identification parameter space.When lesions of the left hemisphere spatial agnosia manifests itself in the form of violations of stereoscopic vision, with lesions of the middle parts of the parietal-occipital region of the disease can be expressed in the form of patient inability to properly locate objects in three dimensions of space, especially in depth, as well as to identify the parameters of further or closer.

There are also such kinds of agnosia as unilateral spatial agnosia - the inability to recognize one of the halves of the space (usually the left), and spatial agnosia, expressed in violation of topographic orientation, in which the patient can not recognize familiar places, but it has nomemory disorders.

One of the rarest types of agnosia is a violation of the perception of time and movement - a condition in which a person can not estimate the speed of time flow and perceive the movement of objects.Last violation of (the inability to perceive moving objects) is called akinetopsia.


As the statistics indicate, agnosia is not a common disease.This condition may be due to a very broad range of reasons, and in each individual case, it manifests itself in different ways.These factors can seriously complicate the diagnosis agnosia: it often requires a comprehensive neurological examination.

When diagnosing agnosia professionals use clinical symptoms of brain imaging techniques (MRI, CT), neuropsychological and physical examination.As a rule, in the first stage of diagnosis the doctor asks the patient to identify any common objects, applying the different senses.Then apply methods of neuropsychological examination, carried out a series of specific tests, during which the physician determines the existing violations of various kinds of sensitivity, and also analyzes the patient's ability to use the senses and correctly identify the received information with them.


Specific treatments agnosia exists.As a rule, the main goal is to treat the underlying disease that led to brain damage and the occurrence of agnosia.However, to compensate for the manifestations of agnosia often resort to neuropsychologists, speech therapists, doctors and occupational therapists.

As practice shows, agnosia treatment is most often carried out in the three-month period - in normal cases this is enough time for recovery of the patient.However, the recovery process may be delayed for a longer period (one year or more).The success of treatment largely depends on the age of the patient, as well as the nature and severity of lesions.


This article is available exclusively in the educational purposes and is not research material or professional medical advice.

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