Timothy C. Hain, MD of Chicago Dizziness and Hearing. If you have questions about this treatment, you can email firstname.lastname@example.org.
Page last modified: July 14, 2016
Mal de Debarquement syndrome (MDDs) is a motion sickness variant that mainly occurs after prolonged motion on a cruise (Hain et al, 1999; Hain and Helminski, 2014). Medical treatment is very limited, but there has recently been a new procedure reported to be helpful.
We duplicated the protocol of Dai et al (2014) to treat Mal de Debarquement Syndrome. They reported cure or substantial improvement of 70% of 24 individuals treated.
|Video Wall at Chicago Dizziness and Hearing||Treatment Paradigm (From Dai et al, 2014).|
We have built a "video wall" consisting of 4 very large televisions (upper left), and we wrote software to duplicate the treatment protocol described by Dai et al (upper right). This is offered through our physical therapy treatment program. An example of the optokinetic stimulus is shown above.
Our system largely duplicates the protocol of Dai et al (2014). This is not a research or study protocol -- this is a treatment protocol for dizziness using habituation, similar to other treatments used for visual dependence. We think that this procedure works through the "pseudocoriolis effect" (Dichgans and Brandt; 1973; Grabiel et al; 1969).
Prior to treatment, we measure symptoms using the simulator symptom questionnaire (SSQ). There are 5 treatments/day for 5 days in a row, again checking on progress each day with another SSQ. We encourage patients to stay in a local hotel, to avoid "undoing" the treatment. It is important to "batch" treatments -- and for this reason we schedule them to all occur in a single week.
Patients have to stop taking certain medications that might block adaptation -- such as benzodiazepine medications (e.g. klonazepam, diazepam (Valium), alprazolam (Xanax), lorazepam (Ativan)), vestibular suppressents (e.g. meclizine), for at least 2 weeks prior to starting the treatment protocol. If patients fly back home after the protocol, we will arrange for them to take klonazepam at the beginning of the trip back.
|Computerized Dynamic Posturography to measure sway.||Dr. Hain performing the Fukuda Stepping Test (Fukuda, 1984)|
1. All patients have an initial evaluation by our vestibular physical therapist. They also see a CDH physician, generally Dr. Cherchi, if they have not already done so. We rarely treat patients who do not fit the usual criteria for MDDs (e.g. Hain and Herdman, 2014) or patients who have not had MDDs for at least 3 months. We will do this if the patient and their doctor understand that they are not a good fit but wish to proceed in any case.
a. Severity of MDDs will be measured using the SSQ.
b. The physical therapist will measure rocking frequency using posturography. While Dai et al used a "Nintendo Wii" to measure postural sway, we use a standard computerized posturography system (see above)
c. Video-oculography is to determine if the subject has vertical nystagmus elicited by rolling of the head at the frequency found in step 1. If, slow-phase velocity is upward with head to the right, and downward with head to the left, we will use an optokinetic stimulus to the left. Otherwise we will use one to the right (see figure from Dai et al. above). This is not our preferred method at this writing (July, 2016). W
d. The Fukuda stepping test (see above, also Fukuda 1984) is used to determine the optokinetic stimulus direction should method b not be conclusive. This is a procedure that involves stepping in place, with eyes closed, on a mat for 30 seconds. The amount of rotation is determined from the rotation in place. This is our favored method at this writing.
e. Should the daily SSQ scores appear to be worsening rather than improving, we switch the direction at mid week. This has only occured once.
2. Patients are seated in front of the optokinetic array shown above. The stripes are rotated at constant velocity (initially 5 deg/sec), while the head is rolled +- 20 deg at their rocking frequency. A metronome is used to set the rocking frequency (typical 1/2 Hz). One click/second, combined with the head going to either side, corresponds to 1/2 hz. There are 4 sessions/day (or more) for 5 days.
3. After treatment is finished, posturography is repeated to measure changes in body sway and rocking.
4. Patients are sent home with a home OKN task. This link describes the use of a web program that provides an OKN stimulus.
|Treatment results in first 17 patients|
Above is the average score of the simulator sickness questionnaire results in our first 17 patients. There was a large drop in symptoms between day 1 and day 2 (i.e. after the first day of treatment). Only one of our 17 patients did not improve comparing day 1 to day 5. We are encouraged by these results, and a little puzzled that our results seem to be even better than those of Dr. Dai's original protocol. We suspect that we will not continue to have such a good record, given that Dr. Dai's experience with a far larger number of patients has been roughly a 60% response rate. There are also some differences -- we use a very large video screen, while the Mt. Sinai protocol uses a "real" OKN drum, and we treat for 10-15 minutes at time on the hour. Another possible difference is patient selection.
Regarding posturography results, pre (before day 1) and post (end of day 5) were obtained in 14 subjects. The average score prior to treatment was 60.6, and after treatment, 71.429. Normal persons generally score about 70, and thus the change of 11 is roughly a 15% improvement. The track record here is more erratic than with the SSQ. There were many subjects whose posturography did not budge at all, and even one patient where the score went slightly down (from 35 to 33). Interestingly, in this patient, there was a very large improvement in the SSQ.
We have a little data about long term results. We have data from 8 patients at week 2. The average SSQ was 8.13 (which is similar to the result at the end of the treatment week), and much better than the pre-treatment average of 15.
We will post more results as more patients are treated.