EAST ORANGE, NJ—A new device that corrects vestibular dysfunction could be a key to treating many of the symptoms affecting the approximately 300,000 veterans who suffer from Gulf War Illness.
Gulf War Illness is a cluster of unexplained symptoms that can include fatigue, dizziness, headaches, memory impairment, joint pain, indigestion, insomnia, respiratory disorders and dermatologic conditions. Nearly 44% of the veterans who served in Iraq and Afghanistan during Operation Desert Storm and Operation Desert Shield in 1990 and 1991 have developed Gulf War Illness, according to the VA.
“Although it’s been more than 25 years since the conflict, we still do not understand the underlying cause of these symptoms and have yet to develop an effective treatment,” explained lead author Jorge M. Serrador, a scientist at the VA’s War Related Illness and Injury Study Center (WRIISC) in New Jersey and associate professor in the departments of pharmacology, physiology and neuroscience at Rutgers New Jersey Medical School.
Many veterans with Gulf War Illness have impaired balance and reduced vestibular function, according to Drew Helmer, MD, director of WRIISC-NJ. Researchers thought those issues might cause other common symptoms such as nausea and dizziness which affect about 20% of veterans with GWI.
Less obviously related problems could arise from vestibular dysfunction, too. “Loss of vestibular function may not produce overt symptoms since patients can use other systems such as vision and other sensory systems to compensate,” Helmer noted. “However, it is possible that this loss will exacerbate other symptoms, such as cognitive difficulties and anxiety.”
To improve vestibular function, Serrador and his colleagues developed an electrical stimulation device that emitted an imperceptible random electrical noise pattern. Clipped to the earlobe, the electrical stimulator sent bilateral, random stochastic noise into the “vestibular systems that traveled through the earlobes into the inner ear, which acts like the body’s accelerometer,” according to Serrado.
The stimulator originally attached to a desktop emitter, but the device is now a portable, palm-sized unit.
In a study presented at the 2018 Society for Neuroscience annual meeting in November, researchers tested the device in 60 Gulf War veterans, 54 of whom had GWI. They also assessed the device’s impact on balance in 36 civilians matched by age and sex to the veteran group.1
About 61% (33) of the veterans with GWI had reduced vestibular function based on otolith-ocular reflex assessment and sway while standing with eyes closed. Among the civilians, the rate of vestibular dysfunction was about half as high, at 29%.
“In fact, despite our veterans with GWI having a mean age of 53, they had values similar to what we see in civilians in their 80s,” Helmer told U.S. Medicine.
Participants received stimulation for 30 seconds up to a few minutes. Because the noise was imperceptible, neither research assistants nor participants could tell whether the stimulation was occurring. Stimulation was turned on and off throughout the testing, and studies were done under both sham and stimulation conditions, Helmer explained.
Improvement Within Seconds
All of the veterans demonstrated an improvement in balance within seconds of stochastic noise stimulation. More than half (53%) experienced a mean improvement of 25% in vestibular otolith-ocular reflex, with the greatest improvement seen in veterans with the lowest baseline scores.
Four out of five veterans also demonstrated an improvement in gait velocity during and immediately following stimulation.
The precise mechanism through which electrical stimulation with random noise patterns or stochastic resonance improves vestibular balance remains unclear, but WRIISC, the National Air and Space Administration and other federal laboratories have previously shown that it can improve performance of motor, cardiovascular, visual, hearing and balance systems, according to a release by the Johnson Space Center.
Improvement in function of many of those systems could also help veterans with GWI, Helmer noted.
“We are currently exploring the possible role that improving vestibular function may have on other symptoms such as cognitive function as well as cardiovascular function. Our lab has previously shown that the vestibular system can affect brain blood flow, so we hope enhancing vestibular function will improve brain blood flow.”
Just improving balance could help with cognitive functions. Remembering things and processing information take a back seat to trying to stay vertical for individuals with vestibular dysfunction. It is like “asking you to answer math questions while walking on a flat surface compared to walking across a balance beam,” Helmer said. “So if we improve vestibular function it may make it easier for veterans with reduced function to concentrate more on cognitive tasks and improve cognitive performance.”
The device may also help other veterans, particularly the elderly. Age-related reduction in vestibular function increases the risk of falls and reduces walking speed, both of which can lead to lower activity levels and reduced quality of life.
Another study led by Serrador and published earlier this year in Nature Scientific Reports found that electrical stochastic noise stimulation of the vestibular system produces mean improvement of 23% in gaze stabilization reflex as measured by ocular counter-rolling gains.2
While the current device is portable, it remains a little large for the kind of use Helmer envisions. “Our eventual goal is to produce something the size of a hearing aid that could be worn continually.”
1. Serrador JM, Schubert MC, Brewer K, Breen P, Wood SJ. Gulf War Illness is associated with reduced vestibular function that can be restored using a novel imperceptible GVS neuromodulation device based on stochastic resonance. Poster: 759: Gulf War Illness: Mechanisms, Causes, and Interventions. Neuroscience 2018. November 7, 2018.
2. Serrador JM, Deegan BM, Geraghty MC, Wood SJ. Enhancing vestibular function in the elderly with imperceptible electrical stimulation. Sci Rep. 2018 Jan 10;8(1):336.