Visual neglect
| Classification according to ICD-10 | |
|---|---|
| R29.5 | Neurological neglect |
| ICD-10 online (WHO version 2019) | |
When visual neglect it is an attention deficit disorder in the form of neglect a room or part of the body (self-centered) and / or object halves (allocentric). It is a special form of neglect related to vision .
The word neglect comes from the Latin “neglegere”, which means “not knowing” or “neglecting”. In fact, those affected neglect one side of their body and their surroundings, always the one facing the damaged hemisphere.
Symptoms
Patients with a visual neglect neglect half of their field of perception, which - depending on the side of the lesion - lies either to the left or to the right of the fixation point. A very important characteristic of this disorder is that the patient does not notice this limitation . He cannot realize that he is neglecting half of the room, even if he is repeatedly shown experimental evidence of his ability. This is an important distinguishing criterion for visual field disorders (see hemianopsia, scotoma): In these cases the patient is blind in parts of his visual field , but he perceives this restriction. Visual field losses are also due to causes other than neglect.
Some exemplary egocentric (on the own body axis) and allocentric (on the general object side) manifestations of visual neglect:
- When eating, the patient only eats from the side of the plate that he does not neglect. He completely ignores this other side. If you now turn the plate by 180 ° so that the omitted side is in the field of perception, the patient eats this half of the meal. Nevertheless, he cannot perceive his disturbance. For example, if you put a plate in front of the patient with neglect on the left side, on the left side of which there are only potatoes and on the right only vegetables and meat, the patient complains that he does not receive any potatoes with his meal.
- Patients wash and shave only half of their body.
- If patients are shown images of faces that consist of two different halves of the face (e.g. left half Bill Clinton and right half Elvis Presley), the patients indicate that they see the full face of the person whose face is on their perceived side .
- A sheet of paper with many horizontal lines is presented to the patient and he is asked to divide each of the lines with a vertical line exactly in the middle. On the one hand, the patient only works on all those horizontal lines that are in his field of perception (and still claims to have completed the task in full). On the other hand, he tends to shift the vertical lines slightly in the direction of his field of perception with each horizontal line instead of drawing them in the middle.
- If the patient is to draw a picture or photo, he only draws the perceived half.
- If the patient is to draw a clock face, he usually paints a complete circle, but only draws every 12 hour markers on the side of the object he perceives.
- The patient is shown the sketched image of a flower. The flower has a thick stem, from which a large blossom branches off to the left and right. If the patient is to draw this two-flowered plant, he only sketches one of the two flowers and neglects the second. However, if the experimenter covers the thick stem of the flower, and thus the common origin of the two flowers is covered, the patient perceives both flowers - but only draws off the perceived half of each flower. The resulting restrictions in daily life can be significant and all other therapies such as B. severely impair the physiotherapy rehabilitation of other disorders (paralysis, etc.) or even make it impossible. The simultaneous presence of a visual or multimodal neglect and a loss of visual field often proves to be particularly problematic.
causes
Brain damage that can lead to neglect syndrome is local / unilateral brain damage, for example after a stroke or head injury, focal epilepsy, or fast-growing tumors. Diffuse brain damage such as poisoning is not a possible cause.
The visual neglect is not - as might be assumed - due to damage to the primary visual system. In neglect patients without loss of field of vision, both the optical pathways and the visual cortex in the occipital lobe are not damaged. Rather, visual neglect is caused by a lesion in the parietal lobe of the cortex . Attention control is located in this area of the brain. With the help of imaging techniques , it has been found that in most people, the right parietal hemisphere is primarily responsible for attention control. This leads back to the fact that most neglect patients have a left-sided neglect:
The left field of perception is controlled by the right hemisphere. If the right parietal lobe is damaged, this important control system fails. If the left parietal cortex (which controls the right field of perception) is damaged, only a slight neglect is observed on the right half of the face. This is attributed to the fact that attention is controlled mainly by the intact right hemisphere and that this can thus partially compensate for the left-sided lesion.
Forms of visual field defects are:
- Hemianopia (hemi-lateral loss)
- Quadrant anopia
- Scotoma
Another central visual disorder is:
There are various approaches to treating visual neglect in the field of clinical neuropsychology . In addition to exploration training, neck muscle stimulation, optokinetic stimulation therapy and prism therapy are successfully used.
Other special forms of neglect
- Olfactory neglect - smelling
- Somatosensitive Neglect - Sense of Touch
- Auditory neglect - hearing
literature
- Gerhard Roth: From the point of view of the brain . Suhrkamp Verlag, Berlin 2009, ISBN 3-518-29515-2 .
Individual evidence
- ↑ a b Neglect at flexikon.doccheck.com, accessed on May 14, 2016.
- ↑ a b c d Roth: From the point of view of the brain . 2009, p. 36 .
- ^ Anthony HV Schapira: Neurology and Clinical Neuroscience E-Book . Elsevier Health Sciences, December 18, 2006, ISBN 978-0-323-07053-9 , p. 79.
- ↑ Causes ( Memento of the original from April 21, 2017 in the Internet Archive ) Info: The archive link was inserted automatically and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. at neuronales-netzwerk.org, accessed on May 14, 2016.
