Timothy C. Hain, MD of Chicago Dizziness and Hearing. If you have questions or comments about this treatment, you can email firstname.lastname@example.org.
Update: the home OKN driver program was updated on 4/1/2017 to eliminate a "stray bar" of different size than the rest, related to monitor resolution. It should also be a little faster. Please let us know if you have problems.
Page last modified: April 2, 2017
This page is for patients with MDDs, who have been treated at Chicago Dizziness and Hearing with the Roll habituation protocol. After the treatment is over, we ask patients to perform the home OKN task. This is a home version of the treatment protocol. The original protocol is shown below in figure 1 from Dr. Dai's paper.
|Treatment Paradigm (From Dai et al, 2014).|
This should be done 4 times/day, for 10 minutes a session. We suggest on the hour, for a half-day, if this is feasible.
While watching the Home OKN task on a large monitor, rock the head about the front-back axis (i.e. roll axis, see figure above), about 15 degrees to the right, and then 15 degrees to the left.
The frequency of the head rocking should be the same as your inner rocking -- this is usually about 1/2 cycle per second -- or in other words, to one side for a second, and then to the other.
The direction of the OKN task should be the same as was used during the CDH roll habituation protocol. Use the arrow keys to control the direction.
Use as large a screen as available, and sit as close as you can without causing blurring to make the OKN stimulus fill your visual field.
You should remain off of medications in the "valium" family such as valium (diazepam), klonopin (clonazepam), Ativan (lorazepam), and Xanax (alprazolam), as these medications are thought to block adaptation in animal models.
You can continue doing this indefinitely if you think it helps.
One might wonder whether or not just doing the "home version" of the OKN habituation task, might not be a reasonable substitute for for the more difficult office version, that requires staying at a hotel near the two practices in the US that do this (New York, Chicago). At this writing, we just don't know.
Dr. Dai and associates have established that the office version works most of the time. So far, nobody has studied the home protocol.
There are several differences between the home and office habituation methods - -
- the speed of the OKN stimulus is not as well controlled (as it depends on the size of the monitor, distance from the monitor).
- Second, for the home task, the head movement is voluntary and under the control of the subject. This is different than for the office version, where a CDH staff member moves the head. Having someone else move the head probably makes the task more effective.
- The smoothness of the scrolling likely varies between different hardware implementations - -at CDH we have a special high-speed graphics card to drive 4 very large TV's. It is likely that it is important that the stimulus moves smoothly across the screen.
- For patients seen at CDH, their diagnosis is generally well established by a physician (otoneurologist), and they perform this protocol under our supervision. For persons who have not been formally diagnosed, it is possible that they have a different disorder entirely. There is no data as to whether or not persons with disorders other than MDDs benefit or perhaps even get worse from this protocol. If you are doing this unsupervised, use it at your own risk.
Other OKN tasks such as "youtube" video's, etc may work as well, but we have not tested these out. We think that small displays (such as cellphones or Ipads) would likely be inferior to large displays (such as TV sets).
There are other programs that produce OKN stimuli that may work as well as the program we have written and provided on this page. We tried one of these on our "video wall", and it was not able to adapt to driving 4 monitors at at the same time. We have no data as to how well it works for the more usual setup.
We have been told that a "short throw video projector" is the optimum method of presenting this OKN stimulus. We have had no direct experience with this. We would think that a large display would be better than small displays.
We do not think that virtual reality goggles, such as the Google cardboard, or one of the many similar gadgets available online using cell phone displays are a reasonable substitute, as they are a very different stimulus (i.e. vision rolls with the head, rather than staying still in space while the head rolls). However, this is uncharted territory.