An occipital stroke affects the back of the brain and can cause an array of visual impairments. These may include the loss of a quarter or half of a person’s visual field or complete blindness.
These strokes may also result in visual hallucinations or the inability to voluntarily direct a gaze.
Because strokes may cause disability and death, immediately call 911 if someone experiences signs,
Keep reading to learn more about occipital stroke, including symptoms, causes, risk factors, visual effects, diagnosis, outlook, and when to seek help.
This is a type of stroke that occurs in one or both of the occipital lobes. These lobes are located in the back of the brain, one on the right and one on the left.
Mainly involved in processing visual stimuli, the occipital lobes have the following functions:
- assessing distance, depth, and size
- identifying familiar faces and objects
- determining color
Additionally, the lobes send and receive information to other parts of the brain.
Learn more about the occipital lobe.
A stroke in the occipital lobes may cause visual and nonvisual symptoms:
- double vision
- loss of part of the visual field, or blindness
- difficulty perceiving color or recognizing familiar faces
- seeing spots or grayness
- difficulty with visual focus
A stroke may affect brain structures that adjoin the occipital lobe, leading to the following
Experts call strokes caused by blockages ischemic strokes. Most strokes are due to blockages. They happen when a blood clot — or other substance — obstructs flow in a blood vessel.
Fatty deposits within the walls of arteries, known as plaque, may also cause an ischemic stroke.
Experts call strokes due to bleeding hemorrhagic strokes. They occur when a blood vessel breaks open or leaks blood. The bleeding puts pressure on brain cells, harming them and causing symptoms.
- younger age
- a prothrombic state, which is a higher tendency to develop clots in blood vessels
A 2020 case study also reports that iron deficiency anemia may be a possible cause of ischemic occipital stroke, but it occurs very rarely.
Other risk factors
Complete cortical blindness
Cortical blindness denotes a loss of vision due to damage in the visual cortex rather than from a condition within the eyes. The visual cortex is the visual processing center of the brain.
When a stroke affects both occipital lobes rather than only one, it can result in a complete loss of vision.
In Anton syndrome, a person has cortical blindness, but they deny it. Someone with this syndrome may experience visual hallucinations or fabrications.
Anton syndrome can also occur when a stroke affects both occipital lobes.
When a stroke affects the parietooccipital junction — the place where the parietal and occipital lobes connect — it can cause Balint syndrome. Symptoms include the:
- inability to voluntarily direct gaze
- inability to reach objects using visual cues
- inability to perceive more than one object at a time
Learn more about Balint syndrome.
Incomplete cortical blindness
Incomplete cortical blindness refers to a partial loss of the visual field due to damage in the occipital visual cortex rather than the eye itself. Most often, the central vision
Some types of incomplete cortical blindness may include:
Contralateral homonymous hemianopia
Homonymous hemianopia refers to the loss of half of the visual field in each eye.
Contralateral means that the visual field loss is on the opposite side of where the stroke occurred. To illustrate, if the stroke affects the right occipital lobe, it will cause vision loss in the left visual field.
Contralateral inferior quadrantanopia or superior quadrantanopia
People have four visual sections, including the:
- right, upper quadrant
- left, upper quadrant
- right, lower quadrant
- left, lower quadrant
Quadrantanopia refers to vision loss in one of these quadrants. Inferior refers to either the right or left, lower quadrant, while superior refers to either the right or left, upper quadrant. Contralateral means that the loss occurs in the opposite right or left quadrant from where the stroke happens.
Charles Bonnet syndrome
Charles Bonnet syndrome involves a gradual vision loss with visual hallucinations or phantom images. An ischemic stroke or tumor in the occipital lobe may cause it, notes
Learn more about Charles Bonnet syndrome.
Strokes affecting blood vessels that supply the back part of the brain are
- Blood tests, such as:
- Imaging tests, such as:
- Cardiovascular tests, such as:
In the United States, stroke is one of the top causes of disability and the
However, when strokes occur solely in the posterior cerebral artery — the artery that supplies the occipital lobes and surrounding structures — disability and death are less likely.
Learn more about stroke recovery.
If a person has any of the
- sudden difficulty seeing in one or both eyes
- sudden weakness or numbness in the leg, face, or arm, particularly on one side of the body
- a sudden loss of balance, trouble walking, dizziness, or lack of coordination
- sudden confusion, difficulty speaking, or difficulty understanding speech
- a sudden, severe headache
Symptoms of an occipital stroke include a loss of a visual field, double vision, or difficulty recognizing faces. They may also entail nonvisual symptoms, such as a headache and a change in consciousness.
The causes involve ischemia or hemorrhage within a blood vessel that supplies the brain. There are various risk factors, which may include conditions, such as obesity, diabetes, and cardiovascular disease.
Strokes in the occipital lobes may cause incomplete or complete blindness and other conditions that manifest visual hallucinations or the inability to reach objects using visual cues.
Diagnostic tools include various blood tests, imaging, and cardiovascular tests. Any type of stroke may cause disability and death, so it is important to call 911 if someone experiences symptoms.