Spatial Neglect Is a Disorder Resulting from Brain Damage: Stroke Is a Common Cause
Spatial neglect results from damage to the neural networks critical for spatial processing and attention orientation. These networks involve both cerebral hemispheres. Through the networks, each hemisphere pays more attention toward the contralateral side of space and deploys more processing resources to stimuli located in the contralateral than the ipsilateral side of space. The extent of network activation in the two hemispheres are relatively similar most of the time, resulting in a balanced or unnoticeable left-over-right spatial bias, if any, in most people.
When one hemisphere is injured, the intact hemisphere is more activated than the injured hemisphere. This leads to excessive bias toward the ipsilesional side of space, while at the same time, the contralesional side appears “neglected.” The networks are asymmetrically larger and more connected in the right than left cerebral hemisphere, and thus, left-sided spatial neglect (after right brain damage) is more prevalent than right-sided spatial neglect (after left-brain damage).
Individuals with spatial neglect do not intentionally or consciously ignore one side of space. They are almost always unaware of their actions, depending on the task (such as reading text messages, locating a house key, wipe-cleaning their face).
When discussing the condition with an individual, it is more appropriate to use the term “spatial neglect” or “neglect” as a noun – a clinical diagnosis – rather than a verb. For example, instead of saying, “you neglect things on your left,” say, “you have spatial neglect, meaning you are not always aware of things on your left side.”
Utilizing Clinical Tools to Deepen Insights into Spatial Neglect
According to Kessler Foundation’s research based on data of more than 4,400 individuals (82% of them were stroke survivors) admitted to rehabilitation hospitals, more than 60 percent of stroke survivors have spatial neglect (see pie charts) and are in need of effective treatment.
To address these challenges, Center research scientists strive to strike a balance between scientific exploration and practical application. Their studies encompass a range of technologies and approaches, from low-tech prism adaptation treatment equipment to innovative virtual reality and mixed reality methods. The Center team is helping to enhance the knowledge and improve the practice of clinicians worldwide with these tools:
- Kessler Foundation Neglect Assessment Process (KF-NAP®)
- Kessler Foundation Prism Adaptation Treatment (KF-PAT®)
- Kessler Foundation Spatial Re-Training Therapy (KF-SRT®) currently in development
- Kessler Foundation Eye Movement Exercise (KF-EME™) currently in development
Read More About Each Tool Read More Research Data
Pie Chart Graphic Key: In a study of 4,454 individuals undergoing inpatient rehabilitation (i.e., in rehabilitation hospitals), 55% were found to have spatial neglect (shown in the larger pie chart). Among those with spatial neglect, stroke and TBI survivors more frequently exhibited neglect on the left side of the brain than the right, as illustrated in the two smaller pie charts.
The Multifaceted Impact of Spatial Neglect on Daily Life
Because of damage to the wide-spread ventral and dorsal attention networks, spatial neglect affects multiple perceptual modalities (visual, auditory, tactile, proprioception) as well as multiple cognitive and motor functions. However, there is no gold standard for its screening, comprehensive assessment, and treatment. The main reason lies in the complexity of the syndrome.
The impacts of the disorder are therefore understandable but underappreciated. More than four decades of clinical research has shown that spatial neglect impedes rehabilitation outcomes, increases the risk of falls, prolongs functional recovery, and worsens stress and burden among family caregivers of stroke survivors.
Neglect Symptoms Vary Across Spatial Regions
Symptoms of spatial neglect can be manifested in different spatial regions, both close to and distant from the body.
All the examples below reflect left-sided spatial neglect, but are also applicable to right-sided spatial neglect.
- Personal space (body parts or body surface). For example, an individual might only shave or apply lotion to the right side of their face, leaving the left side largely untouched
- Peri-personal space (within arm’s reach). For example, experiencing difficulty finding utensils on the left side of a food tray
- Extra-personal space (beyond arm’s reach). For example, overlooking furniture or people across the room on the left side
Symptoms can be egocentric (body-centered, viewer-centered) and/or allocentric (stimulus-centered, object-centered). Clinically, egocentric spatial neglect receives more emphasis because it poses a greater disability risk. This form of spatial neglect involves individuals making errors or omissions, specifically on their left side. In contrast, allocentric spatial neglect involves errors on the left side of an object, regardless of its position relative to the individual.
The Disabling Impact of Spatial Neglect
The deficits created disrupt basic self-care activities (e.g., dressing, grooming), impair postural balance, interfere with reading ability, and impede navigation (e.g., avoiding furniture when using a wheelchair, dodging oncoming vehicles when crossing streets).
Many individuals with spatial neglect are unaware of their own symptoms or the consequences of their deficits (i.e., anosognosia), which delays their seeking appropriate treatment or learning compensatory strategies. This self-awareness deficit can jeopardize safety, especially among individuals who have regained some ambulatory ability after stroke.
Visual Symptoms of Spatial Neglect vs. Visual Field Cut
Visual symptoms of spatial neglect (also known as visual neglect) are more frequently observed and easily noticeable compared to auditory, tactile, proprioception, representational, or motor symptoms of spatial neglect.
Visual field cut is a loss of vision in half (i.e., hemianopia) or one quarter (quadrantanopia) of the visual field. This sensory deficit is caused by damage to the retina, the primary visual cortex, and the neural pathways between the two.
Spatial neglect impairs function of vision, but is not a sensory deficit. Spatial neglect is a neuropsychological syndrome caused by damage to the attention neural networks involving multiple cerebral cortices, subcortical areas, and white matter tracts.
Oculomotor symptoms of spatial neglect, for example, are not about processing information from the retina but more motor-related. The inability to control gaze or eye movement in many individuals with spatial neglect can affect daily functions that require vision.
Some individuals may have both visual field cut and spatial neglect, depending on where the brain is injured.
While a visual field cut tends to remain consistent across tasks, spatial neglect may exhibit variability depending on the task at hand. For instance, individuals with spatial neglect may shave their face evenly but frequently miss the initial words of sentences. They might effortlessly find utensils on a dinner table but struggle to properly set the table. In contrast, individuals with a visual field cut experience blurred vision on one side, regardless of the task they're performing.
Severity of spatial neglect can fluctuate based on alertness (e.g., morning vs. evening), cognitive capacity (e.g., no distraction vs. multi-tasking), and many other factors. Visual field cut does not often fluctuate.
Symptoms of Spatial Neglect in Clinical Settings
Below are symptoms most typically observed in individuals by healthcare professionals and clinicians who specialize in neurorehabilitation and disability research. Stroke survivors with left-sided spatial neglect may:
- Exhibit a propensity to gaze towards the right while at rest, contrasting with their behavior during task engagement
- Tend to shift their gaze towards the right when addressed directly by someone positioned in front of them
- Respond to the right when approached from the left
- Tilt or sit crookedly, with their head and eyes turned to the right
- Have difficulty caring for their left arm and leg. They might leave their left arm outside the wheelchair or let their left leg drag underneath it. They may not use the left arm spontaneously even when the arm has regained function
- Miss words that appear on the left side of a paragraph or food menu when asked to read aloud
- Struggle to locate items in their space on the left
- Have difficulty placing objects evenly on their left and right. Most objects would be clustered on the right side of space
- Have difficulty avoiding objects or obstacles on their left side when moving around indoors
- Lack awareness or concern about issues such as weakness on the left side of their body. This differs from typical denial, where a person may consciously choose to ignore a problem
- Appear unfazed or untroubled when encountering an obstacle during a task, possibly taking a long pause without being able to explain the issue
Stroke survivors with right-sided spatial neglect may demonstrate similar symptoms (by replacing "left" with "right", and "right" with "left" in the examples above). While left-sided spatial neglect is investigated and reported extensively in the research literature, more clinical observations and studies are required to improve the understanding of right-sided spatial neglect.
Early Detection of Spatial Neglect: A Crucial Step for Improved Outcomes
The outlook for individuals with spatial neglect largely hinges on detecting symptoms early. Therefore, the critical first step toward improving outcomes is to identify spatial neglect accurately in individuals who have had a stroke.
Clinical observation and quick tests are essential because individuals with spatial neglect may not always recognize their deficits, making self-reporting unreliable.
A comprehensive evaluation will clearly identify the symptoms of spatial neglect. This evaluation should include a number of different tests sensitive to various symptoms of spatial neglect (e.g., typical object drawing, figure copying, target cancellation with varied difficulty levels, text reading, extinction in visual, tactile, auditory, and motor modalities) and incorporate at least one ecological assessment like KF-NAP® to measure the extent of functional disability.
Assessments for spatial neglect can be carried out by trained professionals, including neuropsychologists, occupational therapists, physical therapists, speech and language pathologists, neurologists, and other clinical specialists.
A person-centered approach and treatment plan should be created after analyzing different test results and quality of performances with consideration of the individual’s self-awareness deficits.
Receive Updates from Kessler Foundation Network for Spatial Neglect (NSN)
The Network for Spatial Neglect promotes accurate detection, direct translation of research to practices, and effective treatments tailored to people with various types of spatial neglect. Provide your contact information to receive updates regarding Kessler Foundation Neglect Assessment Process (KF-NAP®), Kessler Foundation Prism Adaptation Treatment (KF-PAT®), and the Center’s latest studies.
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