Stroke can affect many brain functions
We often think of a stroke as causing hemiparesis, or weakness on one side of the body, but there are many other functions of the brain that can be interrupted by a stroke, and we need to be considerate when people are dealing with these problems.
One such disorder is unilateral neglect, which can occur after a stroke or other brain injury. You may also hear it referred to as visuospatial neglect or hemispatial neglect. The symptoms include an inability to recognize or attend to sensations on one side of the body.
The most prominent symptom of unilateral neglect is unresponsiveness to things that the person would normally see in part of their right or left visual field. For example, a person with a left neglect might not eat the food on the left side of their plate or may bump into things on their left side when walking. For some people this is due to a loss of vision to that side, but others are unable to respond to the things on the affected side even though their vision is intact.
When other sensations are involved, the behaviors will vary. A loss of the ability to recognize sounds or touch on one side will leave a person unable to identify that someone is talking to them, even if that person is next to them and touching their hand.
Hemispatial neglect results from an injury to part of the brain, but because the rest of the brain functions normally it creates a mental representation of the world as whole or intact. That leaves the individual unaware of the sensations that are missing, and most people cannot correct for their neglect through concentration.
Neglect involving memory is quite striking. Memory relies on mental representation of structures and objects. When that is impaired a person may lose the ability to describe parts of their home depending on the perspective from which they are recalling it.
For example, a person with a left neglect may not be able to recall the railing on his stairs if he is “picturing” the stairs from the bottom and the railing is on the left; however, he will be able to recall the railing if he tries to picture the stairs from the top so that the railing would be on his right.
Unilateral neglect occurs in about half of people who have a stroke. It is classically associated with stroke involving the right half of the brain, causing neglect of the left environment or body; however, it may also occur with an injury to the left side of the brain resulting in a right neglect. In some cases it resolves over time.
There are some medical and rehabilitation interventions available when the symptoms persist, but the benefit from these is minor, therefore, the person with these symptoms may have difficulty with their daily activities.
SOURCE: Jim Smith is an assistant professor of physical therapy at Utica College. He can be contacted at email@example.com.