March 2, 2023 - EyeClarity Blog
Visual snow syndrome is a neurological disorder characterized by persistent and often debilitating visual disturbances. People with this condition typically see small, flickering dots or other shapes, known as “visual snow,” that appear to float in the air in all lighting conditions. Other common symptoms include sensitivity to light, difficulty with night vision, afterimages, halos around lights, static in the vision, and problems with depth perception.
The cause of visual snow syndrome is not yet fully understood, although researchers believe it may be related to hyperexcitability in certain brain parts. Some people with the condition also experience tinnitus (ringing in the ears) or other sensory disturbances.
Diagnosis of visual snow syndrome is typically made through a comprehensive eye examination and other tests to rule out other possible causes of the symptoms.
What are the tests for Visual snow?
There is no specific test to diagnose visual snow syndrome. However, a comprehensive vision examination and tests rule out other possible causes of the symptoms. I use a checklist that the patient fills out to determine if they have Visual snow.
Some objective tests to confirm the diagnosis may include:
- Visual acuity test: This test measures how well you can see at different distances.
- Refraction test: This test measures the degree of any refractive error (e.g., nearsightedness, farsightedness, astigmatism).
- Pupil exam: This test checks the size and response of your pupils to light.
- Visual field test: This test measures the range of your peripheral vision.
- Electroencephalography (EEG): This test records the brain’s electrical activity and can help detect any abnormalities.
- Magnetic resonance imaging (MRI): This test uses powerful magnets and radio waves to produce detailed brain images and can help rule out structural abnormalities.
It’s important to note that the diagnosis of visual snow syndrome is primarily based on the clinical presentation of symptoms and ruling out other possible causes of the visual disturbances. If you’ve been experiencing persistent optical interferences for over three months, you probably have Visual snow.
What part of the brain is affected by visual snow syndrome?
The exact amount of the brain involved in visual snow syndrome is not yet fully understood. However, current research suggests it may be related to hyperexcitability in certain brain parts, specifically in the visual processing centers.
The visual snow syndrome may involve both the thalamus and the superior and posterior colliculus.
The thalamus is a small, highly connected structure at the brain’s center. It serves as a relay station for sensory and motor information to and from the cerebral cortex, which is the brain’s outer layer responsible for perception, consciousness, and thought.
The thalamus receives sensory information from the peripheral nervous system, such as touch, taste, smell, and vision. It relays it to the corresponding regions of the cerebral cortex for further processing. The thalamus also receives motor information from the cortex and forwards it to the spinal cord and peripheral nervous system to move.
In addition to its role in sensory and motor processing, the thalamus is also involved in several other functions, including attention, memory, arousal, and regulation of sleep and wakefulness. It is also involved in pain perception and processing.
Overall, the thalamus plays a critical role in transmitting and integrating sensory and motor information and regulating other essential functions in the brain. Dysfunction of the thalamus can lead to neurological disorders, such as thalamic stroke, thalamic pain syndrome, and possibly Visual snow syndrome.
The superior colliculus is a paired structure in the midbrain, just above the cerebral aqueduct. It is part of the brainstem and is crucial in controlling and integrating visual information and coordinating eye and head movements.
The primary function of the superior colliculus is to process visual information from the eyes and other sensory systems, such as the auditory and somatosensory systems, and to generate appropriate motor responses. These fine motor skills include controlling eye movements, such as saccades (rapid, voluntary movements of the eyes), smooth pursuit movements (tracking moving objects with the eyes), and head and body movements.
The superior colliculus receives visual information from the retina and other areas of the brain, such as the visual cortex and the inferior colliculus. It then processes this information and sends output signals to the motor systems in the brainstem and spinal cord, which control the movements of the eyes and other body parts.
The superior colliculus is also involved in attention and spatial awareness. It can direct visual attention to specific objects in the environment and orient responses to sudden or unexpected stimuli.
Overall, the superior colliculus plays a critical role in visual processing and motor control and is essential for generating coordinated movements and integrating sensory information in the brain. Dysfunction of the superior colliculus can lead to neurological disorders, such as gaze paralysis, nystagmus (involuntary eye movements), and visual neglect.
The inferior colliculus is a paired structure in the midbrain, just below the superior colliculus. It is part of the auditory pathway and is critical in processing and integrating auditory information.
The primary function of the inferior colliculus is to receive and process auditory information from the cochlea in the inner ear. It receives input from both the ipsilateral and contralateral cochlea and is involved in binaural processing, allowing us to locate the sound source in space.
The inferior colliculus also plays a role in the filtering and modulation of auditory information. It can amplify or suppress specific frequency ranges in the acoustic signal and modulate auditory neurons’ sensitivity to sound.
In addition to its role in auditory processing, the inferior colliculus is also involved in multisensory integration. It receives input from other sensory systems, such as the visual and somatosensory systems, and can integrate this information to enhance or suppress auditory processing.
The inferior colliculus is a critical relay center in the auditory pathway and plays a crucial role in processing and integrating auditory information in the brain. Dysfunction of the inferior colliculus can lead to a range of auditory processing disorders, such as tinnitus, hyperacusis, and auditory processing disorder.
Some studies have shown that people with visual snow syndrome have altered functioning in the visual cortex, the part of the brain that processes visual information. Specifically, there may be increased activity in the visual cortex, which could cause hypersensitivity to visual stimuli.
In addition to the visual cortex, other brain parts may also be involved in visual snow syndrome. For example, there may be alterations in information processing between the visual and auditory systems, which could explain why some people with visual snow syndrome also experience tinnitus or other sensory disturbances.
Overall, regarding the exact neural mechanisms underlying visual snow syndrome, further research is needed to understand the condition better and develop effective treatments.
What are the treatments for Visual snow?
I have found that physical vision therapy, yoked prisms, tinted lenses, and color therapy can help reduce visual snow symptoms. Eating an anti-inflammatory diet, learning stress reduction self-regulating practices, and receiving craniosacral therapy and acupuncture can reduce Visual snow syndrome symptoms.
Other treatments include:
- Lifestyle changes: Avoiding triggers such as bright lights, reducing stress, getting enough sleep, and avoiding alcohol or drugs that may worsen symptoms.
- Medications: Some medications, such as lamotrigine, topiramate, and benzodiazepines, have been reported to relieve some people with visual snow syndrome. However, the effectiveness of these medications can vary widely, and they can have side effects.
- Transcranial magnetic stimulation (TMS): TMS is a non-invasive treatment that uses magnetic pulses to stimulate specific brain areas. Some studies have suggested that TMS may improve visual symptoms in some people with visual snow syndrome.
- Cognitive-behavioral therapy (CBT): CBT is a form of psychotherapy that can help people with visual snow syndrome learn to manage their symptoms by changing their thoughts and behaviors.
- Neurofeedback: Neurofeedback is a form of biofeedback that uses brainwave monitoring to help people with visual snow syndrome learn to regulate their brain activity.
It’s important to note that the effectiveness of these treatments can vary widely, and what works for one person may not work for another. It is essential to know that anxiety and depression can accompany the Visual snow syndrome.
Since the visual and auditory pathways drive the condition, vision therapy is a viable option to treat this condition.