Balint syndrome is a rare neurological condition that affects visual perception. This may cause difficulty controlling eye movements and not seeing individual objects as part of a group. Hand-eye coordination can also be challenging due to changes in perception.

People with Balint syndrome typically have lesions on the bilateral parietal and sometimes occipital lobes of the brain. Bilateral means both sides of the brain, so lesions from Balint syndrome can appear on the left and right sides of these lobes.

The goals of Balint syndrome treatment are to manage and reduce any lasting effects of disability. This could involve adaptive approaches, such as strengthening affected brain areas through perceptual skills training.

In this article, we will discuss Balint syndrome, including its causes, symptoms, and treatment options.

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Some researchers refer to Balint syndrome as Balint-Holmes syndrome, though Balint syndrome is the more common name. Rudolf Bálint — a neurologist and psychiatrist, first described the symptoms in 1909.

Balint syndrome describes a rare brain condition that affects vision. It usually occurs due to damage to the parietal lobes of the brain. The parietal lobe is one of the four major lobes of the cerebral cortex in humans and sits near the upper back portion of the skull, close to the parietal bone.

In some cases, damage to the occipital lobe may also result in Balint syndrome. The occipital lobe is behind and slightly underneath the parietal lobe.

These areas of the brain are responsible for sensory perception, and damage to these lobes may lead to dysfunction in the senses.

Because Balint syndrome is so rare, researchers are unable to accurately estimate the number of people who live with it. Generally, most case studies involve adults. However, some have recorded Balint syndrome in children as young as 4 years old.

People with Balint syndrome typically experience three symptoms to different degrees. This trio of distinct visual symptoms includes:

  • Simultanagnosia: This refers to problems with visual attention. For example, when looking at a picture of a forest, a person may be able to see each tree but cannot recognize a forest. This may carry over into issues with reading or being able to find people in busy environments.
  • Optic ataxia: This term describes a problem with coordination. Alternatively, it is when the brain can no longer fully control simple movements with the visual information it receives from the eyes. Consequently, people with Balint syndrome often knock things over and may have difficulty reaching for objects.
  • Oculomotor apraxia: This is also known as some loss of voluntary eye movement. When this happens, a person may not be able to avert their gaze and look at something else, which may give the impression they are staring into space. Their eyes may also dart around without them realizing it.

Balint and Anton syndrome are both rare neurological conditions that affect visual perception, but their symptoms are very different.

A person with Balint syndrome experiences visual disturbances, while someone with Anton syndrome has a complete loss of vision but truly believes they can see. The medical term for this is visual anosognosia — a denial of vision loss.

Because a person thinks they can see, they may try to explain their loss of vision. As such, telling symptoms of Anton syndrome include insisting lights need switching on and commenting on how dark places are.

Unlike other forms of blindness, occipital lobe damage is one of the main causes of vision loss in Anton syndrome, not damage to the eyes or optic nerves. When brain injury causes a loss of vision, a person has cortical blindness.

A blood clot in the brain or stroke is the most common cause of Balint syndrome. However, any damage or trauma to the parietal areas and occipital lobes can also trigger symptoms.

Other causes include:

A diagnosis of Balint syndrome relies on physical symptoms, such as simultanagnosia and optic ataxia. There are no diagnostic criteria for brain imaging studies.

That said, a doctor may request a CT scan or MRI scan to check for changes to the parietal and occipital lobes when they suspect Balint syndrome. However, this is only to support their diagnosis. Imaging studies alone cannot confirm this condition.

Moreover, a PET scan may show a lack of adequate blood supply to the parietal and occipital lobes, for example, in cases of stroke, which could also support a diagnosis.

Treating Balint syndrome focuses on rehabilitation and reducing any lasting effects of disability. This may include occupational rehabilitation, such as training perceptual skills to repair areas of brain damage, or strategic learning when this is not possible. If a person develops Balint syndrome after a stroke or infection, preventive treatment can reduce the likelihood of these conditions returning and damaging the brain further.

The prognosis of Balint syndrome depends on the underlying cause. If a person develops Balint syndrome after a stroke, a combination of rehabilitation therapies and medication can help reduce symptoms. However, if the condition is a symptom of a neurodegenerative condition, such as Alzheimer’s disease, it will likely worsen with time.

Balint syndrome affects a person’s visual perception. The three main symptoms include simultanagnosia, optic ataxia, and oculomotor apraxia. A diagnosis of Balint syndrome depends on the presence of these symptoms. However, as most people experience them to varying degrees, there is no typical case of the condition.

As brain damage is a common cause of Balint syndrome, treatment tends to focus on rehabilitation. Prevention of further brain damage is especially important for people who have experienced a stroke or traumatic brain injury. If Balint syndrome is a symptom of neurodegeneration, such as progressive dementia, symptoms are more challenging to treat.