Does a stroke affect perception?


Brief overview

  • Description:Neurological disorder due to brain damage. Those affected no longer perceive the side of the body that is opposite the damaged brain area. Different forms: visual neglect, auditory / acoustic neglect, somatosensitive neglect, motor neglect, olfactory neglect.
  • Causes:mostly stroke, rarely tumors or dementia such as Alzheimer's.
  • When to the doctorAlways call the emergency doctor immediately if additional stroke symptoms occur, for example one-sided paralysis, slurred speech, paresthesia, loss of feeling in certain parts of the body. If the only symptom is neglect, see a doctor.
  • Diagnosis:based on the behavior typical for neglect (neglect of one side of the body). In addition, test procedures such as line halving, search and strike-through tasks, reading tests and drawing exercises.
  • Treatment: Sometimes neglect disappears by itself. Otherwise, therapy methods such as targeted training of the affected side of the body, cues on the affected side (e.g. colored line on the neglected edge of the table), training of eye and head movements on the neglected side, self-instruction technique, technical aids, vibrator for the neck muscles neglected side of the body, prism lenses.

Neglect: description

A neglect is a neurological disorder caused by brain damage.

The term goes back to the Latin word “neglegere”, which means “not knowing” or “neglecting”. Because those affected no longer perceive one side of their body and their surroundings or "neglect" them. This is always the side opposite the damaged hemisphere. Since the right hemisphere is more often affected by brain damage than the left, a neglect usually occurs on the left side of the body.

What happens with the neglect?

In neglect patients, the sensory organs such as eyes, ears and skin as well as the nerve tracts on the affected side of the body are completely intact. They function normally and send their signals to the brain. This is where the problem lies: the brain cannot process the signals from the sensory organs into conscious impressions - one speaks of a disturbed secondary perception. This causes the patient to neglect the affected side of the body. You see, hear and feel nothing there. Sometimes, even when there is pain on this side, they do not react or only react with delay.

Most of the time, those affected do not even notice a neglect because they have completely faded out the affected half of the body. It is possible for them to focus their attention specifically on the affected half of the body. Then this also comes back to consciousness. However, the patients must be asked to do so, they cannot do it on their own.

The symptoms of a neglect

In acute neglect, those affected usually turn their eyes and head towards the damaged hemisphere. It is also typical of a neglect that the patient uses one side of the body much more than the other.

A neglect can affect individual or all sensory organs and regions on one side of the body. Depending on which areas are affected, a distinction is made between different forms of neglect:

  • Visual neglect: Those affected can no longer see anything with the eye of the affected half of the body. Your field of vision is limited to the section of the healthy side of the body.
  • Auditory or acoustic neglect: The patients on the neglect side do not hear anything and therefore do not react when spoken to from this direction. In addition, they cannot assign where noises come from.
  • Somatosensitive neglect: Affected people do not react or react too slowly to touch or pain on the side of the body affected by the neglect. They often locate the touch or pain on the unaffected side.
  • Motor neglect: The patients hardly or not at all use the voluntarily controllable muscles on the affected side. However, unconscious movements such as blinking or chewing usually work.
  • Olfactory neglect: The patients cannot perceive any odors around the affected side of the body.

Neglect patients usually have a limited field of vision. That is why they are only half aware of their environment. This manifests itself, for example, when eating, when one side of the plate is not emptied. Often those affected hit the affected side of the body with an arm or leg. Many also apply make-up or shave only half of their face.

A neglect also influences visual memory: if those affected are asked to describe or draw well-known places, people or objects, for example, they only paint one half. Even if they already knew the respective motif before the neglect appeared. This is known as representational neglect.

Neglect: causes

Most of the brain damage that can lead to neglect syndrome is due to a stroke. This is caused either by a circulatory disorder (ischemic stroke) or bleeding (hemorrhagic stroke or cerebral hemorrhage) in certain areas of the brain. Brain tumors and dementias such as Alzheimer's are less likely to cause neglect.

A neglect mainly occurs when the right hemisphere has been damaged. Neurologists therefore suspect that this half of the brain is more important for processing sensory stimuli than the left. This is also supported by the fact that the right hemisphere can often partially compensate for a failure of the left, while the reverse is not possible.

Diseases with this symptom

Find out here about the diseases that can cause the symptom:

Neglect: when do you have to see a doctor?

If a stroke caused the neglect, those affected usually suffer from other typical symptoms. These include suddenly occurring unilateral paralysis, abnormal sensations, a loss of feeling in the affected body regions and slurred speech.

If you notice these signs in yourself or in people around you, you must call an emergency doctor immediately. Because when you have a stroke, every minute counts.

If a neglect is the only symptom, the disorder often goes unnoticed for longer. Because those affected are not aware of their deficits, and the people around them do not always notice the signs immediately.

If you notice that someone suddenly only uses one side of the body to a very limited extent or not at all, often bumps into objects and apparently no longer perceives impressions on one side of the body, then you should ask whether the person concerned notices this himself. If this is not the case, an acute neglect is likely and a visit to the neurologist or hospital as soon as possible is important.

Neglect: what does the doctor do?

First, the doctor examines whether the patient actually has a neglect. There are special test procedures for this, several of which should be carried out. Because only the totality of the test results allows a reliable diagnosis. However, an experienced doctor can usually recognize severe forms of neglect from the patient's behavior. Then there is no need for complex test procedures.


There are several methods of diagnosing neglect. These include, for example:

  • Line bisection tasks:Have the patient split horizontal lines on a piece of paper with the pen exactly in the middle. In neglect syndrome, the halving is shifted towards the healthy side.
  • Search and strikeout tasks: The patients are given a sheet of paper with different, evenly spaced symbols on it. The task is to mark all of the same symbols. If there is a neglect, the patient marks significantly more symbols on one side than on the other.
  • Reading tests and drawing exercises: When reading aloud, neglect sufferers often leave out words at the beginning of the line. The disturbed perception of one side of the body is also evident when drawing. For example, while drawing a clock, those affected paint a round clock face. But all the hours are drawn in only one half.


After a stroke, the neglect symptoms sometimes go away on their own after a few weeks. If the neglect persists, special therapy methods can alleviate the symptoms, for example:

  • targeted training of the affected side of the body with regard to everyday activities such as eating, dressing or combing
  • Cues on the affected side like a colored line on the neglected edge of the table
  • systematic training of eye and head movements on the neglected side
  • Self-instruction technique: In doing so, the person concerned gives himself the "command" to take the neglected page into account (e.g. "When writing, first look for the left edge of the line").
  • technical aids: So those affected can carry a small device in their pocket on the neglected side of the body. The device sends a tone at irregular intervals, which those affected have to turn off with the neglected hand.
  • special vibrator: This can stimulate the neck muscles on the neglected side of the body. Experiments have shown that neglect symptoms can sometimes be reduced in this way.
  • special glasses (prism lenses): The patients wear the prismatic lenses during various exercises. Although this method is still in the trial phase, it has delivered good results in initial studies.

Important investigations

These examinations help to find out the causes of the symptoms:

Neglect: You can do that yourself

After a stroke, those affected should start mobilizing the damaged areas as early as possible. This supports optimal regeneration. However, there is a risk that you will not even notice neglect disorders yourself - and thus not recognize the need for action.

Tips for relatives

Relatives and friends can support the healing process. Basically, it helps to specifically promote and stimulate the neglected side. For example, by deliberately handing objects to the neglect side, or by moving glasses and cups towards the neglected half of the table. If the patient's arm is drooping while sitting, family members may ask that the patient place that arm on the back of the chair or table. If necessary, they have to help him with this.

It is also possible to set up the person's bed so that they are lying with their healthy side facing the wall - when getting up they have to turn over to the neglected side. However, this method is controversial as it can be extremely worrying for neglect patients.

Relatives have to be patient with those affected, because neglect syndrome disrupts their attention. Therefore you should speak clearly and slowly and take breaks between exercises. In addition, the sick can appear emotionally changed. So if you suddenly have trouble expressing your feelings correctly, that is often the cause Neglect.

Author & source information