Novel approach to prevent motion sickness

A novel treatment may soon end the misery of motion sickness suffered by many people across the world.

The cause of motion sickness is still a mystery but a popular theory among scientists says it is to do with confusing messages received by our brains from both our ears and eyes, when we are moving.

While most feel a bit uneasy after a rollercoaster ride, about one-third of people experience significant symptoms on long bus or car rides, on ships or in light aircraft. These symptoms include dizziness, severe nausea, cold sweats, and more. Current therapies are at best only partially effective.

In a novel approach, a team of researchers from Imperial College London used mild electrical current to the scalp to suppress the vestibular activity and thereby increase the tolerance to motion stimuli. The results were published recently in the journal Neurology.

Sensory information about motion, equilibrium and spatial orientation is provided by the vestibular system in the inner ear. The electric current applied over the left parietal cortex, which is located at the back of the brain above the ear, suppresses the vestibular system that is responsible for processing motion signals.

To test the effectiveness of the method, researchers applied mild electric current to the scalp of volunteers using either a cathode or an anode for 15 minutes. The volunteers were then asked to sit in a motorised rotating chair that also tilts to simulate the movements that tend to make people sick on boats or rollercoasters. The stimulation using current was continued for a further period of 15 minutes during rotation or until they reported moderate nausea.

Those who got the left cathodal stimulation took a longer time to develop moderate nausea compared with those who got left anodal stimulation. The volunteers who were less susceptible to motion sickness derived the most benefit from the cathodal stimulation. Also, the time taken to recover was “significantly reduced.”

“We are really excited about the potential of this new treatment to provide an effective measure to prevent motion sickness 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,” Michael Gresty, a co-author of the paper from Imperial College said in a release.

“We are confident that within five to ten years people will be able to walk into the chemist and buy an anti-seasickness device. We 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,” Dr Qadeer Arshad from Imperial College London who led the team said in the release.

The research team is beginning to talk to people in industry about developing the device.

Published in The Hindu on September 14, 2015