What is Balint Syndrome?
Balint syndrome was first mentioned by Rudolf Balint in 1909. Basically, it’s a disorder that includes:
- The inability to see more than one thing at once in their field of vision.
- The inability to see different items at the same time in a visual scene.
- Difficulty reaching an object with the right hand, but not with the left hand.
Despite these problems, the patient had normal vision, color vision, and eye muscle movements. An examination after the patient’s death pointed to symptoms from chronic brain diseases in both sides of the back part of the brain, which could have caused this syndrome. At that time, it was thought that the symptoms were due to a disconnect between sensory input (information obtained through senses) and motor output (muscle movements).
In 1919, Holmes and Horrax wrote about a similar case. They believed that the patient’s inability to touch or point to objects was just due to visual disturbances. The patient didn’t have problems with sensory or motor tasks that didn’t require visual input. Therefore, they suggested that the main problem existed in visual fields.
What Causes Balint Syndrome?
Balint syndrome is often caused by ischemic infarctions, or blockages in blood flow, in certain parts of the brain. This typically happens in two areas on both sides of the brain: the parietal and occipital areas.
Furthermore, Balint syndrome has been reported in connection to a number of other neurological disorders. These include:
* A reversible brain condition known as Posterior Reversible Encephalopathy Syndrome (PRES)
* Alzheimer’s disease
* Creutzfeldt-Jakob disease, a rare and fatal brain disorder
* Posterior Cortical Atrophy, a condition that causes damage to the back parts of the brain
* Corticobasal Degeneration, another rare neurological condition
* Subacute HIV Encephalitis, a brain disorder linked to HIV infection
* Progressive Multifocal Leukoencephalopathy, a disease affecting the brain in people with weakened immune systems
* Head trauma
* Cerebral toxoplasmosis, a brain infection
* Brain metastasis, where cancer cells from another part of the body spread to the brain
In recent times, there have been reports of patients having something called NMDA receptor encephalitis, a brain disorder that presents similarly to Balint syndrome. There’s also a reported case of what’s termed idiopathic Balint syndrome, where the cause is unknown.
Risk Factors and Frequency for Balint Syndrome
Most of the information available on Balint syndrome comes from individual case reports. There are no exact statistics available on how often it occurs. While most of these reports concern adults, there are also cases involving children as young as 4 years old.
Signs and Symptoms of Balint Syndrome
Balint syndrome is a rare disorder that involves difficulty coordinating vision and spatial perception. It typically presents with three main characteristics:
- Optic ataxia
- Oculomotor apraxia
- Simultagnosia
Optic ataxia refers to a disconnect between what a person sees and how their hands move. For instance, a person with optic ataxia cannot successfully complete tasks that need them to guide their movements solely by what they see. Yet, if provided with other cues like touch or sound, they can nonetheless perform the task. This condition may stem from damage to a part of the brain responsible for the visual-motor coordination.
Oculomotor apraxia is when a person cannot voluntarily move their gaze or focus, even though their eye muscles are functioning correctly. This condition was initially linked to damage in certain areas of the brain, but later research has indicated that damage to the frontal eye fields can also lead to oculomotor apraxia.
Simultagnosia is the inability to perceive more than a single object at once. For example, a patient might be able to view each individual tree in a painting of a forest, but cannot comprehend the entire forest scene. This condition can make patients appear to be functionally blind and can interfere with activities requiring simultaneous viewing of multiple objects, like reading or counting. It’s further classified into dorsal and ventral types, each associated with damage in different regions of the brain and each presenting with distinct symptoms.
In essence, Balint syndrome is characterized by the inability to use visual information to guide motor actions, such as hand movements or eye focus, despite one’s normal visual acuity, functional extraocular movements, and the ability to recognize colors and objects.
Testing for Balint Syndrome
Doctors might suspect Balint Syndrome based on certain symptoms. Unfortunately, this condition is often misdiagnosed because people tend not to know much about it. There aren’t any specific brain scan markers that definitively indicate this syndrome. However, brain scans, such as Computed Tomography (CT) scans and Magnetic Resonance Imaging (MRI), often show shrinkage changes in certain parts of the brain – the parietal and occipital lobes.
Even though these scans don’t directly confirm Balint Syndrome, they often show signs that line up with the underlying cause of the syndrome. If Balint Syndrome is suspected based on these signs and a person’s symptoms, other tests will be done to figure out the exact cause. In some situations, they might even use a particular type of brain scan known as a single positron emission computed tomography scan, which can tell if certain areas of the brain are not getting enough blood.
Treatment Options for Balint Syndrome
The primary way to handle Balint syndrome is through rehabilitation and minimizing the disability as much as possible. In certain situations, such as blood clot, a brain disorder called PRES, or infections, we can take additional preventative steps to reduce the chances of it happening again. Several strategies in occupational rehabilitation can help people minimize the impact of their symptoms.
The adaptive method focuses on using their untouched abilities to lessen the disability caused by the symptoms. The remedial method seeks to fix the damaged areas of the brain by teaching them how to perceive things again. The third, and more complicated approach, is the multi-context approach. This method involves learning strategically in an environment with many tasks to be performed.
What else can Balint Syndrome be?
Hemineglect is a condition often caused by damage in the temporoparietal junction, a certain area of the brain. It should not be confused with Balint syndrome, a different neurological disorder. People with hemineglect may show signs that resemble symptoms of other conditions. For instance:
- They might have abnormal eye movements which seem similar to ocular apraxia, a condition where a person struggles to move their eyes.
- They might have problems with hand movements that appear like optic ataxia, a condition where a person has difficulty reaching for objects with their hand under visual guidance.
- They might also have perception difficulties that mimic simultagnosia, a condition where a person has trouble perceiving more than one object at a time.
In summary, it’s important to correctly identify the symptoms in order to differentiate hemineglect from similar conditions.
What to expect with Balint Syndrome
The chances of recovery from Balint syndrome largely depend on what’s causing it. If triggered by sudden onset conditions like stroke, infections, or a condition called PRES, patients, with the right treatment, may have a good chance of recovering. However, if Balint syndrome comes from ongoing brain diseases such as corticobasal degeneration or posterior cortical atrophy, the outlook isn’t as positive.
Possible Complications When Diagnosed with Balint Syndrome
Aside from the distressing symptoms that come with Balint syndrome, there are no known serious complications reported in patients living with this condition.
Preventing Balint Syndrome
If a person starts noticing unusual symptoms like difficulty coordinating their hand movements with their vision, problems paying attention to more than one thing at a time, or issues seeing different objects in their visual area, these could be rare signs of a condition called Balint syndrome. At this point, it’s vital they get checked by a neurologist – a doctor who specializes in nerve-related disorders. The neurologist can confirm whether these symptoms point to Balint syndrome or not.