A new treatment being developed by scientists from Imperial College London could end the misery of motion sickness.
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A new treatment being developed by scientists from Imperial College London could end the misery of motion sickness. By suppressing certain brain signals they found they could speed up a person's ability to adapt to motions that had previously caused symptoms such as dizziness, nausea and vomiting.
Research from Imperial College London, recently published in the scientific journal Neurology, explained how motion sickness occurs when what the eyes see and what the inner ear senses are confused. Clinical scientist Dr Qadeer Arshad hit upon the idea for treating motion sickness when investigating what can influence a person's sense of balance.
"We know that people without a functioning balance system are almost immune or highly resistant to developing the cardinal symptoms of motion sickness, which are nausea and vomiting. And so we developed a separate line of research; a way of using brain stimulation to suppress the signals from the inner ear and the brain. And so we thought that if we suppress signals at the level of the brain from the inner ear, then this would be highly effective against motion sickness," Arshad told Reuters.
Most people are prone to a mild queasy feeling at some point, for example on boats or rollercoasters. But around three in ten people suffer from a more severe type of motion sickness, leading to more unpleasant symptoms, such as dizziness, severe nausea and cold sweats.
Professor Michael Gresty, a world expert on motion sickness, collaborated in the study at Imperial College London. He said it's the conflict in the brain that triggers these feelings of nausea as it struggles to figure out what position the body is in.
"The reason that we can't understand these motions; the brain if you like can't understand these motions, is that there's continual conflict between what is upright and whether you should lean to balance yourself in the environment or whether you're actually experiencing a sideways acceleration force. You imagine being on a bicycle or a motorbike; you go round a corner, you lean into the corner which remains perfectly upright in physics. You don't so that in a car, you don't do that on a ship - you're actually struggling to find out what is upright and what's the best way of dealing with it," said Gresty.
During experiments carried out at the Department of Neuro-otology at Charing Cross Hospital, test subjects were first asked to sit in a motorized rotating chair that also tilts to simulate the motions that tend to make people sick on boats or rollercoasters.
Arshad said this was to determine each individual's vulnerability to motion sickness: "What we wanted to do was compare each individual to themselves, because people have varying degrees of susceptibility. So we initially go people on the chair and found out how susceptible they were, so we measured how long it took them to develop motion sickness. We then applied a stimulation; either the test or the control, i.e. the placebo. And then we re-measured how long it took to develop motion sickness."
Subjects were rotated at 72 degrees per second, equaling one revolution every five seconds, with the chair tilted at 17 degrees. Arshad said this generated a frequency that is particularly nauseagenic.
Once their level of susceptibility had been determined, volunteers wore electrodes on their heads for about 10 minutes while again undergoing motion in the simulator. Known as transcranial direct current stimulation (tDCS), the application of a mild electrical current to the scalp caused the brain to suppress responses in an area responsible for processing motion signals. Volunteers found that they were less likely to feel nauseous and they recovered more quickly.
"So what we found was that when we used the test condition, we found that it took longer for the individual to develop motion sickness and that they also recovered faster. Whereas in the control group they developed motion sickness sooner than the first time and they took longer to recover," added Arshad.
After further lab based experiments, Arshad says the next step is to field test the device to determine how quickly it can speed up a person's adaptability to motion sickness in the real world.
The researchers are confident that within ten years a consumer device could be readily available; one that the user could simply plug into their smart phone and attach to their scalp. They say the electrical currents are so small that there is no reason to expect any adverse effects from short term use.
"The technique has been around for some time, we've been using it for a long time. And for these very small amounts of electricity that you're putting through the brain there are no reported unwanted side effects or interactions," said Gresty.
"So the chances of it becoming a commercially viable prospect are quite imminent really," he added.
(Source: Reuters)
