We’re not saying that it’s not an injury of the brain; it may be. We do know for sure that it is an injury to the ear and that the brain is affected. —Michael E. Hoffer, MD
Explore This IssueFebruary 2019
On physical examination, most (95%) of the symptomatic individuals reported dizziness, and approximately half (56%) had cognitive complaints. The most common complaints described dizziness and disorientation and being in what is called a “cognitive fog,” in which something feels off.
No subjective or objective otolaryngologic or neurologic findings of this nature were found in the 10 people without symptoms, who were in the same house when the symptomatic person was exposed.
Upon further testing and evaluation, these subjective symptoms were validated by auditory and neurological tests that confirmed that the 25 symptomatic individuals had specific symptoms related to vestibular disturbance and cognitive dysfunction. Symptoms included:
- Unsteadiness (or loss of balance and disorientation);
- Cognitive dysfunction characterized as decreased clarity of thought (“cognitive fog”); and
- Difficulty with emotional regulation, including increased anxiety and irritability.
Bonnie E. Levin, PhD, director of the division of neuropsychology and Bernard and Andrea Schoninger Professor of Neurology at the University of Miami Miller School of Medicine and coauthor of the study, talked at the press conference about how this constellation of symptoms (vestibular, cognitive, and emotional) cluster together. “My assessment of these individuals was that these symptoms were not random, were not isolated, and they actually fit together as a constellation of symptoms. Their subjective complaints were confirmed by objective neuropsychological testing showing a constellation of behavioral, emotional, and cognitive dysfunction,” she said, adding that this cluster is found to be related to vestibular damage and dysfunction in animal and human studies. Dr. Levin listed a number of specific symptoms validated by neurological testing (see “Neurological Symptoms Confirmed by Objective Tests,” below).
“We don’t know the exact source, but we do know that there is a common anatomic pathway that underlies this particular constellation of events, which involve vestibular, cognitive, and emotional change,” she said.
What the study did not find, contrary to some reports in the media, was that symptomatic patients had hearing loss. Auditory assessment in most patients did not show hearing loss, except in two persons who had prior hearing loss.
Also contrary to some reports in the media, the injuries sustained were not like traumatic brain injuries, said Dr. Hoffer. “We’re not saying that it’s not an injury of the brain; it may be,” he said. “We do know for sure that it is an injury to the ear and that the brain is affected.”
The outstanding question, he said, is whether the brain was affected directly or from the ear. “We don’t know and haven’t determined that yet,” he said.