Visual neglect: how it affects patients after a stroke

Visual neglect, also known as hemispatial neglect, is a neuropsychological disorder characterized by the inability to attend to, respond to, or perceive stimuli on one side of space, despite the absence of primary sensory loss. This condition is often a consequence of stroke, particularly when it affects the right hemisphere of the brain.

What is visual neglect?

Visual neglect is a disturbance in spatial attention. Patients are unaware of visual stimuli on the side opposite to the affected cerebral hemisphere, even though their visual capacity remains intact.

For example:

• If the right hemisphere is damaged, the patient ignores the left side of their environment.
• They may fail to notice objects, people, or even parts of their own body on the affected side.

Visual neglect is more common after damage to the right hemisphere, which controls attention to both sides of space, whereas the left hemisphere primarily manages the right side.

Relationship between visual neglect and strokes

Strokes, especially those occurring in the right parietal lobe region, are the most common cause of visual neglect. This phenomenon occurs when brain damage affects the areas responsible for processing spatial attention.

1. Stroke in the right middle cerebral artery:
   • It disrupts communication between the brain’s visual and attention areas, leading to a lack of perception on the left side.
2. Functional impact:
   • Patients may ignore food on one side of the plate, fail to dress one side of the body, or not respond to stimuli on the affected side.
3. Impact on recovery:
   • Visual neglect complicates rehabilitation, as patients have difficulty actively participating in physical and cognitive therapies.

Causes of visual neglect

In addition to strokes, other causes include:

• Traumatic brain injuries:
  • Injuries to the right hemisphere of the brain.
• Brain tumors:
  • Pressure on areas related to spatial attention.
• Neurodegenerative diseases:
  • Such as advanced Alzheimer’s disease.
• Encephalitis or brain infections:
  • Inflammation that affects visual processing.

Symptoms of visual neglect

Symptoms can vary in severity, but the most common are:

• Ignoring objects or stimuli on one side of space.
• Frequent collisions with obstacles on the affected side.
• Difficulty reading because the patient does not see the beginning of lines.
• Lack of personal care on the affected side, such as not combing hair or dressing completely.
• Spatial disorientation or a feeling that the environment is incomplete.

Diagnosis of visual neglect

Diagnosis requires a thorough neurological and neuropsychological evaluation:

1. Line or figure cancellation tests:
   • Patients are asked to cross out lines on a sheet or complete drawings, showing if they omit the affected side.
2. Visual field testing:
   • To differentiate visual neglect from primary visual loss, such as hemianopsia.
3. Functional clinical evaluation:
   • Observation of the patient’s behavior during daily activities.
4. Brain imaging:
   • Computed tomography (CT) or magnetic resonance imaging (MRI) to identify the underlying brain lesion.

Treatment of visual neglect

Treatment focuses on rehabilitation and functional adaptation:

1. Targeted attention therapies:
   • Training for the patient to consciously direct attention toward the affected side.
2. Sensory stimulation:
   • Use of visual, auditory, or tactile stimuli on the neglected side to improve perception.
3. Therapies with optical prisms:
   • Glasses that shift stimuli toward the functional visual field.
4. Cognitive rehabilitation:
   • Exercises designed to improve spatial attention and environmental awareness.
5. Psychological support:
   • To manage frustration and the emotional impact associated with this condition.

Living with visual neglect

People with visual neglect face significant challenges in daily life. The following strategies can help:

• Home adaptations:
  • Place important objects on the functional side.
• Visual scanning techniques:
  • Training to consciously move the head and eyes toward the affected side.
• Family support:
  • Educate caregivers to facilitate the patient’s adaptation.
• Use of assistive devices:
  • Tools such as talking clocks or audible alarms.

Prevention of visual neglect in stroke

Although it is not always possible to prevent visual neglect, the risk of strokes can be reduced with measures such as:

• Controlling risk factors such as high blood pressure, diabetes, and high cholesterol.
• Maintaining a healthy lifestyle with a balanced diet and regular physical activity.
• Avoiding tobacco use and excessive alcohol consumption.
• Having regular medical check-ups to detect cardiovascular problems.

Conclusion

Visual neglect is a complex and debilitating condition that can arise as a consequence of strokes. Although there is no definitive cure, rehabilitation strategies and appropriate support can make a significant difference in patients’ lives.

Understanding this condition and addressing it through a multidisciplinary approach is essential to improve quality of life and promote a more complete recovery after a stroke.

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