At North 49 our team of vestibular therapists look for nystagmus in determining one’s cause of dizziness. So, what is nystagmus? It is simply repetitive, uncontrolled eye motion. It usually affects both eyes. Depending on the cause it may be constant or intermittent. It can also be temporary or permanent.
It will look like a stuttering motion of the eyes. This motion can be linear (upward, downward, or laterally), rotary, or a combination. Sometimes it can be seen in room light while other times it cannot. Health care providers therefore use infrared goggles to make sure that they do not miss seeing it.
It can be due to several causes such as:
It typically occurs when there is a problem with sensory input (most commonly the inner ear), processing system (brain), or motor output (eye movement) of the vestibular system. The vestibular system works like anti-shake in a GoPro to keep the image we are seeing in focus while we are moving. The vestibular system is also key in our general orientation and ability to keep upright.
So, if there is a problem with the input from one of the inner ears due to a condition such as BPPV or an inner ear infection the brain will receive information that the body is moving when it actually is not. The brain in turn tells the eyes to move to keep up with the perceived motion, resulting in nystagmus. Now, if there is a problem with the brain, it can also send the eyes the wrong information and cause nystagmus. Lastly, if there is a problem with the eyes themselves, this can cause nystagmus.
Who treats it depends on the cause. This is determined by how long it has been present, other associated symptoms, and the physical exam. For example, if the onset was recent and associated with vomiting, headaches, double vision, slurred speech, falling, or choking on foods immediate medical attention would be required. On the other hand if it is associated with dizziness and is bothersome for seconds at a time with looking up, bending forward, or rolling over in bed, a trip to a physical therapist who has specialized training in vestibular therapy would be recommended. In this care there is a high chance that the nystagmus is due to BPPV. Of note, BPPV is the most common form of dizziness across the lifespan.
Click HERE For further information about BPPV.
Sometimes you can simply see the nystagmus in a mirror or with holding your cell phone close to your eyes. It can be seen at times when the head is still and when you look straight ahead, which is called spontaneous evoked nystagmus. Sometimes it is more prevalent when you look to the side which is called gaze evoked nystagmus. With both spontaneous and gaze evoked nystagmus this could be due to a brain or inner ear problem.
To help determine if it is coming from the brain or inner ear a trained health care provider will use infrared goggles. If the nystagmus is due to an inner ear problem it will be more prevalent when the goggles are on and you cannot see anything. With nystagmus coming from the brain it will be just as easy to see in room light as when you wear the goggles and cannot see anything. There are other tests that the care provider can perform as well to help tease this out.
Movement of the head or positional changes can also cause nystagmus. A common example would be with BPPV, where either lying back suddenly with the head turned 45 degrees to the side or turning your head quickly while lying on your back causes temporary nystagmus. Again, it will be easier to see if you wear infrared goggle and your vision is obscured.
There is no simple answer for this as it depends on the cause. If it is due to a condition such as Multiple Sclerosis, the nystagmus could be constant or intermittent and never go away. On the other hand, if it is due to BPPV it will recur for seconds to minutes at a time until the BPPV is treated.
Click HERE for treatment options for BPPV.
If you have any further questions, please feel free to contact us at 306-343-7776.