Motion sickness effectively treated with mild brain stimulation

Scientists are working on a motion sickness treatment based on brain stimulation that could one day become an easy-to-use portable device you pick up from the pharmacy, or even apply directly from your smartphone.

The researchers say the results show the device offers benefits that are close to those of the best travel sickness medications available.

Researchers from Imperial College London in the United Kingdom UK state that the treatment - which delivers a mild electrical current to the brain - lasts for around 10 minutes, works by applying electrodes to the scalp and appears to have no side effects.

A small trial of the device that they report in the journal Neurology shows it has promise as a new treatment for motion sickness.

The researchers are confident that within 5 to 10 years people will be able to walk into the chemist and buy an anti-seasickness device.

In fact, the benefit such a device could bring to people constantly plagued by motion sickness:

"The problem with treatments for motion sickness is that the effective ones are usually tablets that also make people drowsy. That's all very well if you are on a short journey or a passenger, but what about if you work on a cruise ship and need to deal with motion sickness whilst continuing to work?"

Motion sickness is a common condition that most people have experienced at one time or another - perhaps on a turbulent ferry crossing, or on a particularly rough rollercoaster ride. But for around 3 in 10 people, it can involve much worse symptoms such as severe nausea, vomiting, dizziness and cold sweats.

Transcranial direct current stimulation

Nobody knows exactly what triggers motion sickness, but many scientists believe it has something to do with the brain trying to process conflicting signals from our ears and our eyes when we are moving.

Previous research has shown that a functioning vestibular system - the part of the inner ear that senses movement - plays an important role in the development of motion sickness. The researchers decided to test what happens to symptoms of motion sickness if you dampen the signals from the vestibular system to the brain.

One way to dampen the movement signals from the inner ear is to apply transcranial direct current stimulation through the scalp to the brain region responsible for processing them.

Transcranial direct current stimulation (tDCS) is a non-invasive, painless treatment that uses weak, direct electrical currents to stimulate specific parts of the brain.

There are two types of tDCS - anodal stimulation, which increases brain cell activity, and cathodal stimulation, which inhibits or reduces it.

For their study, the researchers invited ten men and ten women to wear a cap fitted with electrodes on their heads through which they underwent tDCS for approximately 10 minutes. They then underwent a well-tested method of simulating motion sickness where they sat in a chair that rotates and tilts at different speeds.

Participants receiving tDCS had less nausea and recovered more quickly

The trial was a double-blind trial in that neither the participants nor the technicians administering the treatment knew whether the tDCS being given was the type that dampens the inner ear signals (cathodal stimulation) or not (anodal stimulation). Participants had been randomly assigned to receive either one or the other.

The results showed that the volunteers who received the correct treatment were less likely to feel nauseous and recovered more quickly.

The researchers are very excited about the potential of the device to offer an effective alternative to current treatments with no apparent side effects. The benefits that we saw are very close to the effects we see with the best travel sickness medications available.

The research team is already in talks with potential industry partners about developing the device further. Other parties have also expressed interest. One potential military use for the device, for example, would be to treat remote control drone operators who can get motion sickness from looking at screens that show what the drone cameras see.

In the future, the researchers foresee the development of a device similar to a TENS (transcutaneous electrical nerve stimulation) machine that is used to treat back pain, or perhaps something even more portable:

The researchers hope it might even integrate with a mobile phone, which would be able to deliver the small amount of electricity required via the headphone jack. In either case, you would temporarily attach small electrodes to your scalp before traveling - on a cross-channel ferry, for example.

The researchers say the currents involved are very weak and can see no reason to expect any adverse side effects from short-term use. In the following video, they describe the device, how the team tested it and how people might use it in the future:

Currently, tDCS is still considered an experimental form of brain stimulation - it is yet to be approved by the US Food and Drug Administration (FDA).

References:

1.  Electrocortical therapy for motion sickness, Qadeer Arshad et al., Neurology, doi:10.1212/WNL.0000000000001989, published online 4 September 2015, abstract.
2.  Imperial College London news release, accessed 6 September 2015.
3.  Additional source: Johns Hopkins Medicine, Transcranial direct current stimulation, accessed 6 September 2015.