Mal de Debarquement Syndrome (MDDS) is a condition characterised by constant feeling of rocking/swaying. Usually this comes on after a boat ride (hence the name). It can also occur after a plane, train or car ride or even spontaneously. Often patients feel better if they are back in a car, boat, plane or train. There may be overlap with chronic subjective dizziness. Some patients have other symptoms sensory sensitisation.
The cause and best treatment for MDDS are not clear. Some patients improve spontaneously. For other the problems persists. Some benefit from a drug Clonazepam. Other treatments tried include magnetic stimulation (see here).
Recent research by Dr Dai et al in 2014 (see here) has suggested that optokinetic visual stimulation (optokinetic treatment) can help some patients. Patient with MDDS were placed in a room with a screen with a moving black/white stripe pattern (it is important that the whole visual field is covered) while their heads were tilted (rolled see video below) 20 degree from side to side (ear to shoulder alternatively) by an assistant for 3 to 5 minutes, 1 to 8 times a day for 1 week. The pattern either moves from left to right or vice versa. The direction of movement of the visual field (to left or to right) was determined by some balance tests. The sway frequency of the side to side tilt was determined by the patient’s own rocking/sway frequency.
As with any treatment these results need to be replicated before it can be considered a reliable treatment.
I do not have any reliable treatment to offer my patients with this problem at present. I am also not aware of any reliable treatment prior to Dr Dai’s therapy. I recognise many patient with MDDS suffer greatly with this condition. I have therefore modified the treatment as proposed by Dr Dai to allow it be delivered at home.
You Tube recently introduced of 360 degree videos. This therefore, allows optokinetic type treatment at home. Some equipment including (at present) an Android smartphone (a phone model with a built in a gyroscope/accelerometer is required) and a Google Cardboard Type virtual reality (VR) goggles (see here) will be required. The Archos VR Headset allows some custom adjustment for focus and inter-pupillary adjustment. This or similar headset may therefore be more suitable for patient with glasses. The high end phones such as Samsung Galaxy Note and S model have the required built-in gyroscope/accelerometer. If you are planning on purchasing an Android phone for this purpose you will need to check with the retailer if it has this ability. It may be possible to try a phone in the shop one a 360 You Tube video to see if it works as required.
You will also require internet connection usually via WiFi.
There is no guarantee that this treatment will be successful.
I have created a 360 degree optokinetic video. To obtain the optokinetic effect these will have to be viewed with VR Goggles. Looking at a computer screen is unlikely be effective. The whole visual field will need to view the optokinetic video.
I have loaded these videos on to you tube:
Optokinetic pattern with movement to right
Optokinetic pattern with movement to the left
360 degrees video are a new format of video which allows the viewer to see all round via VR goggles. Google (who own You Tube) have created a standard for a type of budget Goggles which can be replicated and reproduced cheaply (Google Cardboard). These type of Goggles can be purchased from various makers (including eBay) for as little as £20. The Archos VR Headset allows some custom adjustment for focus and inter-pupillary adjustment. This or similar headset may therefore be more suitable for patient with glasses. They are designed to work with a smart mobile phone. Android phone can at present play the 360 degree You Tube video format in a way that allows viewing through the Goggles. iPhone’s can not do this at present. It will I suspect, become available to iPhone soon. The key feature allowing a true virtual experience is the ability for the smartphone’s in built detectors to keep the visual field level while the view moves his/her head. Watching a normal video through the Goggles with smart phone does not replicate this.
The viewing angle with these goggles is somewhat limited. It may be possible to replicate the optokinetic treatment using the virtual reality Goggles playing the optokinetic video as carried out by Dr Dai et al.
Prior to carrying out the treatment Dr Dai et al determined 2 pieces of information to guide the treatment: Rotation and Sway frequency.
In some patient it is possible to determine whether the video rotation to the left or right will be beneficial. This can be potentially determined by a patient walking on the spot with eyes closed for 1 minute. This should be repeated twice. If the patient turns to the left then the video to the right can be used for therapy and vice versa. In Dr Dai et al research vidoenystagmography was also used to determine which video to use but it will not be possible to do this at home without specialist equipment. In some patient it was not possible to determined which rotation to use. In these case the patient was tried with one and then the other to see which provided benefit.
2. Sway Frequency
The researchers used a balance platform and a wrist accelerometer to determines the sway frequency. Again I suspect it may be possible for a independent viewer to look at a patient trying to stand still with eyes close to get an idea of the sway frequency. The patient themselves could also count out the number of sways (while eyes closed) in a minute. This figure can the be divide by 60 to to determine the frequency. In Dr Dai et al paper this averaged at 0.2 Hz. i.e. the patient were swaying at a rate once every 5 seconds. If the sway frequency can be determined or estimated then this can be used to determine the frequency of rolling/tilting of the head during the treatment session. An assistant can then tilt the head from side to side (bringing the ear close to the shoulder) at this frequency during the treatment session. Assume we have a case with a frequency of 0.2 Hz. Starting with the head in neutral position followed by tilt to left then to right and then straight should take 5 seconds.
Setting up android phone for viewing 360 videos
Head Rolling/Tilting approximately 20 degrees / 0.2 Hz., while wearing a Google Cardboard VR Goggles.
Dr Dai et al treatment consisted of viewing the optokinetic video stimulation (either to the left or right) while the head was tilted (rolled) 20 degrees side to side by an assistant at the sway frequency (see 2. above) for between 3 to 5 minutes. This was repeated 1 to 8 times a day for 1 week.
Once the VR Googles have been obtained they are assembled as per manufactures instructions. The relevant You Tube video is started on the smart phone (using the You Tube app). If the video is paused or the screen taped a menu appears on the screen. On the right upper part of the video are 3 dots in a vertical row (setting menu). This is pressed and another menu appears. Press the Cardboard icon. The video now splits in to 2. The video will also restart. The smart phone can now be inserted in to the Goggles. Looking straight ahead will give the optokinetic stimulus. Looking down or up reveal that impression you are in a tube. The head can now be tilted 20 degrees side to side at the sway frequency for the desired amount of time. Some patient may not be able to tolerate this very well and may feel nauseous.
There is also the theoretical potential for some patient to feel increased dizziness.
In the treatment by Dr Dai et al the patients scored their problem between 0 (no rocking) to 10 (most severe) before and after the treatment. The patient average score improved from 6.8 to 0.7. The patient rocking was also assessed with a balance platform. The results that Dr Dai et al have obtained seem impressive. From the 24 patient treated 70% improved and none deteriorated.
I would not recommend this treatment for patients who have photosensitive epilepsy.
Recommended workplace adjustments and hacks for people with Mal de Debarquement Syndrome (MdDS) to maintain/improve productivity.
Work in natural lighting whenever possible
Rehydrate – little and often
Try to avoid working in visually ‘busy’ environments
Reduce glare and blue light from computer screens
Take regular breaks from screen use and go outside if you can
Avoid working in spaces where there are strong smells, including after-shave and scent
If you use the telephone a lot, consider using a head-set so you have even audio input
Avoid using shuttle buses
Service (enclosed) elevators may be preferable to glass ones. [Worth noting that MdDS is a spectrum condition and some people with this condition may not do well in enclosed spaces and/or that this may change, over time]
If your job involves walking and/or standing in line (eg in a canteen), consider using a walking cane for added proprioceptive input and extra stability