Occipital lobe damage can cause a person to experience different vision problems. While other types of TBI may result in a wide variety of side effects, damage to the occipital lobe is unique because it generally affects one thing: sight.
However, vision problems can manifest in different ways. This makes it important to gain a better understanding of how occipital lobe damage can affect someone, and what rehabilitation methods are available.
This article will explain the various symptoms and treatments for damage to the occipital lobe. Let’s get started.
Understanding the Occipital Lobe
The occipital lobe, located in the rear portion of the cerebral cortex, is primarily responsible for visual functions. It is the part of the brain where visual information is processed.
After it is processed, visual information leaves the occipital lobe via two major pathways: the dorsal stream and the ventral stream.
The ventral stream is a pathway that leads to the temporal lobe. It carries information related to object form, color, and recognition. Essentially, it helps the temporal lobe determine “what” you see.
The dorsal stream, on the other hand, carries information about where objects are in space. It flows into the parietal lobe, where it is further processed.
As you can see, the occipital, parietal, and temporal lobes interact closely together. Therefore, the symptoms of occipital lobe damage can overlap with those associated with parietal or temporal lobe damage.
Symptoms of Occipital Lobe Damage
The symptoms of occipital lobe damage involve vision and perception problems.
The most common symptom of occipital lobe damage is blindness and visual distortions, such as hallucinations. But there are several other symptoms a person can experience as well.
1. Partial Blindness
Partial blindness happens when only a portion of your visual environment is impaired.
Partial blindness can manifest in several different ways, including:
- Hemianopsia – Half of your visual field, either horizontally or vertically, is gone.
- Quadrantanopsia – A quarter of your visual field is lost.
- Peripheral vision loss – The outer edge of your visual field is lost.
- Central vision loss – The middle of your visual field is lost, but the peripheral vision is fine.
You can also develop something called homonymous hemianopsia. This occurs when the same part of the vision field is lost in both eyes. For example, the left half of your vision would be gone on both your right and left eyes.
2. Word Blindness (Alexia)
Occipital lobe damage also leads to an inability to read/recognize written words.
It occurs when visual information from the occipital lobe cannot pass to the areas of the brain that process language.
It’s similar to receptive aphasia, except it doesn’t affect the ability to understand spoken words. Instead, looking at a piece of writing would just look like strange lines and symbols.
3. Color Agnosia
Color agnosia is similar to normal color blindness. Except whereas color blindness affects color perception, color agnosia affects color knowledge.
With color agnosia, the mechanisms in the eye that enable a person to see color remain intact. But the person could not tell you what color they see.
This means that a person with color agnosia would be able to pass a normal color blindness test, but they couldn’t tell you what color a banana is, for example.
4. Akinetopsia (Motion Blindness)
This rare condition causes a person to not perceive motion in their visual field. Instead, you might see motion as a series of stills, like something moving under a strobe light.
In severe cases, you might not be able to detect motion at all, but your vision of stationary objects would still be intact.
5. Simultanagnosia (Balint’s syndrome)
This symptom makes it almost impossible for a person to perceive more than one object at a time. It is common after both parietal and occipital lobe damage.
For example, a person with Balint’s syndrome who looked at a house may only see a door or a window, instead of the whole house. They also could not see their fork if they were looking at their plate.
Other symptoms include:
- Optic Ataxia. Difficulty reaching for an object you are looking at.
- Oculomotor Apraxia. Inability to move your eyes in a coordinated, purposeful way (i.e. moving your eyes towards a specific object).
A person with Balint’s syndrome would also be unable to read, because they could only process one letter at a time.
Treatment for Occipital Lobe Damage
To deal with occipital lobe damage, your best course is to start occupational therapy, which can help you learn effective compensatory tactics.
For example, people with word blindness can utilize strategies that many blind patients use to read, such as text-to-speech programs or braille.
In addition, some treatments that might help you recover some of your vision include:
- Eye exercises. These exercises engage your brain’s neuroplasticity and can help improve vision.
- Scanning therapy. This therapy helps patients with visual field loss learn to compensate by scanning their environment more efficiently.
- Prismatic adaptation. During this treatment, the patient wears special prismatic glasses that shift the visual field to one side, forcing the person to look towards the affected side in order to reach an object. It is effective for those with hemispatial neglect or hemianopsia. This therapy helps retrain the brain to process vision on the affected side. It works best when combined with visual scanning training.
To take part in scanning therapy and other treatments for occipital lobe damage, make an appointment with a certified vision rehabilitation specialist, typically a neuro-optometrist.
Even though they might not cure your vision loss, they can help make living with it a little easier.
Occipital Lobe Injuries: Key Points
Damage to the occipital lobe can cause blindness and other visual distortions, including hallucinations.
Although living with visual problems can be difficult, therapists and neuro-optometrists can help you adapt and make things a little easier. Vision therapy techniques might also help you improve the vision you still have.
Keep in mind that the brain is remarkably adaptive. With enough therapy, it can actually rewire nerve cells to allow undamaged brain regions to take over functions from damaged ones.
Which means even if you have severe occipital lobe damage, you might still regain your sight after brain injury. Good luck!