Neglect

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Classification according to ICD-10
R29.5 Neurological neglect
ICD-10 online (WHO version 2019)

In neurology, neglect (from Latin: neglegere = not knowing, neglecting) is a disturbance of attention that is caused by damage to the brain ( brain lesion ) and which is characterized by the fact that the person concerned is on the side of his environment opposite the brain lesion or not or only poorly perceive or disregard one's own body. This is often accompanied by a primarily lack of awareness of the disease . The neglect shows itself through several symptoms , which can be differently pronounced and not all have to occur together.

In most neglect patients, the right hemisphere is affected and the left side is limited in perception. The characteristic disregard can relate to stimuli from all senses. Most of the time, several or all five senses are affected. At the same time, the motor skills on the affected side are disregarded: the extremities are moved significantly less, even if there is no paralysis . A neglect often occurs after major right-hemispheric infarctions or bleeding of the arteria cerebri media . Accordingly, stimuli on the left side of the room are mostly neglected. The affected patients are usually not aware of their deficits and initially perceive their behavior as normal.

Neglect is sometimes mistakenly diagnosed in patients with a restricted field of view . In the case of visual field restrictions, however, only vision is affected, and the patient's insight into the disorder is usually much better.

Definition of terms

A distinction must be made between neglect and anosognosia . For conceptual reasons, however, both disorders must be regarded as belonging to the group of neuropsychological disorders, namely as sub-forms of agnosia ( a-noso-gnosia ).

Since neglect is an English-language distinction, anyone who uses these terms should be aware that basically a comparison with denial of illness is appropriate here. Klaus Poeck emphasizes that anosognosia is aptly characterized as denial of illness .

With such a linguistic comparison it becomes clear that anosognosia is the more comprehensive and the general systematic name. However, this does not have to mean that anosognosia is also the more serious disorder, as the linguistic comparison between neglect and denial suggests.

The first person to describe it , Joseph Babinski , already highlighted various degrees of severity of anosognosia. He distinguished between denial of paralysis in response to pressing questions (anosognosia) and indifference to disability (anosodiaphoria). This distinction is also made in more recent literature between terms such as explicit denial and implicit denial . A closer differentiation can hardly be made by neuroanatomical, but rather has to be made by psychological criteria, such as B. Narcissistic attitude , self-image and body schema . This is also expressed linguistically when patients in the regression phase convey expressions of strangeness to the affected, mostly left half of the body, by referring to them as he or she or as silly billy. It has therefore also been spoken of partial depersonalization phenomena . Corresponding linguistic terms are to be seen as an expression of the fact that the patient begins to deal with the part of the body that has been alienated and denied.

Symptoms

A neglect patient overlooks things that are on the contralesional side. He bumps into obstacles such as B. Doors or chairs that are on this side, he only eats half of his plate, shaves only half of his face, skips individual words while reading and can not find the things he is looking for or only with difficulty when they are open the contralesional side. In short, a neglect patient simply overlooks one side of the world around them. Neglect patients therefore find it difficult to find their way in everyday life. Neglect patients rarely or not at all react when they are addressed or touched from the contralesionary side, sometimes not even when pain is inflicted on the restricted half of their body. Since the neglect occurs in several modalities (visual, auditory and tactile), it is also known as a multimodal disorder. The disorder can occur in several modalities, but does not have to be. Neglect is an attention disorder because it is as if the patient is simply not paying any attention to the restricted area. If you ask him to concentrate on objects or objects on the neglected side, he can temporarily perceive them, but he does not do this on his own initiative. A neglect patient can see, hear and feel normally, but he simply does not notice stimuli that are on the restricted side. Patients usually only look to the side of the lesion (ipsilesional side) and rarely look to the affected side of their own accord. This means that most neglect patients are constantly looking to the right. If you are looking for an object, e.g. If, for example, a circle is depicted on a sheet of squares, look for it first on the ipsilesional side and rarely, if ever, look at the contralesional side. The neglect is often associated with anosognosia , so the patients are not aware of their limitation. Most neglect patients therefore answer when asked about their perception that they can perceive their entire field of vision without restriction.

Object-relatedness of the neglect

The neglect is related to the object, the body or the environment, depending on the situation the patient is in. This means that depending on what the patient is concentrating on or what he is paying attention to, other things will be overlooked. If the patient walks through a room and concentrates on the space that surrounds him, he will overlook objects and obstacles on the left side of him (if the left side of the body is the one affected by the disorder). If he looks at a line on a sheet and wants to cross it out in the middle, he will overlook the left half of the line and cross it out on the right side rather than in the middle.

The neglect even affects memories. In an experiment by Bisiach and Luzzatti (1978) neglect patients were asked to describe a cathedral square from their memory from a certain perspective. Here, distinctive parts of the space were left out of the description, namely the parts which, from the perspective of the description, were on the opposite side to the brain damage. If the patients were asked to mentally describe the place from an opposite position, they would explain the details more precisely on the side that they had previously omitted from the description from the other direction. This suggests that attention works with a mental representation of the environment, which can be affected by brain damage.

anatomy

A neglect does not only occur with a specific damage in the brain, but can be the result of damage in different places in the brain. However, this damage is usually only in one hemisphere of the brain and mostly relates to the area between the parietal, temporal and occipital lobes . A neglect can also occur in rare cases after a frontal lobe lesion. Also subcortical lesions in the putamen and caudate nucleus of the basal ganglia or Pulvinars in the thalamus can lead to neglect. From a functional point of view, it is damage in association areas (secondary receptive cortex fields), mostly anosognosia caused by foci in the right parietal region.

Effects

The effects on everyday life differ depending on the severity of the disorder. For example, patients with pronounced neglect have difficulty reading because they cannot find the beginning of the line. When it comes to personal hygiene, the neglected side is ignored, e.g. B. when shaving or applying makeup. Some of the food on the plate is ignored. During the conversation, it is noticeable that neglect patients usually do not look at their conversation partner or only for a short time. When they hear acoustic stimuli from the neglected side, they often turn their head in the other direction, searching. In the case of severely affected patients, intensive care is necessary, as they are e.g. B. can neither dress alone nor go to the toilet alone.

Neuropsychological diagnostics

Various methods have been developed to detect neglect; this includes halving the line, searching and crossing out tasks, tracing and reading tasks. No single method is sufficient to be able to report a neglect with certainty, as the symptoms vary in severity in different patients. However, by performing several tests, one can make a fairly confident judgment about the presence of neglect.

Line bisection

The test person is presented with horizontal lines that he should cross out in the middle. Shifting the halves to one side suggests a neglect.

Search and strike through tasks

The test person receives a sheet of paper on which various symbols, e.g. B. letters or squares, are randomly distributed. He should now look for objects of one kind and cross them out. Neglect patients tend to leave out the symbols on one side.

Copy or free drawing

The test person is asked to trace a picture (e.g. of a house or a table) or to draw an object from memory, such as a clock. Neglect patients leave out parts of their drawings, usually on the contralesional half of the motif. B. only half an o'clock.

Reading tasks

Here the patient is asked to read a text out loud. Neglect patients often forget words that are at the beginning of the line.

Serious neglect disorders usually do not require complex neuropsychological diagnostics, but can be recognized with a little experience through behavioral observation alone. In cases of doubt or in order to precisely determine the severity of the disorder, however, a neuropsychological evaluation is required.

therapy and progress

The neglect usually improves spontaneously, and in approx. 65% of the patients no more neglect is detectable after 15 months. The remaining 35% have further significant restrictions. An early onset of neuropsychological therapy can demonstrably improve the neglect. Patients with a right neglect generally recover faster than patients with a left neglect.

A whole range of methods are now available for treating neglect: In addition to visual exploration training, vibration therapy of the neck muscles, alertness training, optokinetic stimulation and adaptation to prism glasses are used. The advice often given in the past to put patients with neglect with their healthy side against a wall or in bed so that they are forced to explore their neglected side is no longer given. It has been shown that at least severely affected neglect patients do not succeed in exploring the neglected side and they suffer greatly from the situation that has been forced upon them.

There are several ways to temporarily relieve the symptoms of neglect. In principle, it has proven useful to temporarily increase the activity in the damaged hemisphere. The restriction caused by the neglect can be temporarily partially or even completely removed with the help of caloric stimulation. With caloric stimulation, either warm or cold water is flushed through the ear canal in the ear. It should be noted, however, that flushing the ear canal can briefly lead to nystagmus , severe dizziness, vomiting and even (in rare cases) to epileptic seizures. Under no circumstances should the patient tilt his head forward during irrigation, as this will increase the effect on the vestibular organ . Vibration massages on the neck have also proven helpful in temporarily reducing the symptoms of neglect.

Explanatory models

There are several theories that try to explain the phenomena of neglect. Due to the distributed places where brain lesions result in a neglect, some neuroscientists suspect that the neglect is a sign that attention as a cognitive process takes place in different places in the brain or is distributed over several areas and therefore an interruption of the Connections of these areas to one another can lead to disturbances in attention. According to Kinsbourne, each of our two hemispheres creates an attention vector that directs attention to the opposite side of the outside world and suppresses the other hemisphere. So both hemispheres of the brain struggle to focus attention on objects in their opposite area. If one half of the brain is damaged, it can no longer adequately suppress the other half of the brain, and this thereby gains an advantage in the competition for attention. The frequent occurrence of left-sided neglects as a result of right-sided brain lesions has led to the assumption that the influences of both hemispheres on attention are not evenly distributed, but rather lateralized. The right hemisphere probably has the ability to direct attention to both the left and the right side of the environment, whereas the left hemisphere only has an influence on the right side of the environment. If one assumes that this theory is correct, the neglect can be explained as follows: A (partial) failure of the left hemisphere leads to difficulties in perceiving the right part of the visual field, but the right hemisphere can partially compensate for this limitation. However, if the right hemisphere fails, the left hemisphere cannot function properly and the left field of vision is neglected. Michael Posner and co-workers suspect three main processes of attention due to the different forms of neglect, which can each turn out individually: 1.) The release of attention from an object (disengagement), 2.) The shifting of attention (movement) and 3.) the renewed attention to a new object (engagement).

Special forms of neglect

literature

Web links

Individual evidence

  1. ^ Klaus Poeck : Neurology. 8th edition. Springer-Verlag, Berlin 1992, ISBN 3-540-53810-0 , p. 141.
  2. ^ Joseph Babinski : Contribution à l'étude des troubles mentaux dans l'hémiplégie organique cérébrale (anosognosia). In: Rev.Neurol. 27 (1914), pp. 845-848.
  3. ^ EA Weinstein, RL Kahn: Personality factors in denial of illness. In: Arch. Neurol. Psychiatry. 69 (1953), pp. 355-367.
  4. ↑ Paul Schilder : The body scheme. A contribution to the teaching of the awareness of one's own body. Springer, Berlin 1923.
  5. ↑ M. Crtichley: Personification of paralyzed limbs in hemiplegics. In: Brit. med. J. (1955) II, pp. 284-286.
  6. ↑ H. Ehrenwald: Anosognosia and Depersonalization. In: Neurologist. 4 (1931), pp. 681-688.
  7. ↑ Thure von Uexküll u. a. (Ed.): Psychosomatic Medicine. 3. Edition. Urban & Schwarzenberg, Munich 1986, ISBN 3-541-08843-5 , p. 948.
  8. ↑ E. Bisiach, C. Luzzatti: Unilateral Neglect of Representational Space. In: Cortex. 14: 129-133 (1978).
  9. ↑ Peter Duus : Neurological-topical diagnostics. 5th edition. Georg Thieme Verlag, Stuttgart 1990, ISBN 3-13-535805-4 , p. 390.