Doctors Find Viral Link to Vertigo : Medicine: Outbreaks in Wyoming, and later in Atlanta, were traced to an enterovirus. Discovery could lead to a cure.

One fall morning Belinda Willson stepped out of bed and nearly plunged to the floor. Her world was spinning around.

“My first thought was, I better lie back down,” she said. “It was kind of scary, actually. Here you are, perfectly normal, and here you are, spinning around like on one of those carnival rides.”

But the roller coaster effect lasted several hours. It turned out to be the first of many such rides Willson would take over the next few weeks.

She wasn’t alone.

Her husband, a physician, suffered it, as did her 17-year-old son and 12-year-old daughter. In all, about 60 Thermopolis residents ages 8 to 80 experienced violent vertigo in various degrees in the fall and winter of 1992. When doctors investigated the outbreak, they found that 35 people, or 1% of the town’s population, had never had the vertigo before.

“That [the 35] sounds like a small number of people that were infected, but if extrapolated across the nation, that means that 2 1/2 million people would have had vertigo in a six-month period,” said Dr. I. Kaufman Arenberg, an ear specialist in Denver.

“Our patients in the hospital were acutely ill. They were so dizzy they couldn’t eat. The slightest movement of their head made them vomit,” said nurse Colleen Hanson of Hot Springs Memorial Hospital.

The problem was usually ascribed to flu symptoms or an ear infection. Nobody suspected an outbreak until Hanson made an offhand remark to Arenberg, who was treating her husband for a worse ear affliction known as Meniere’s disease.

Researchers from the federal Centers for Disease Control and Prevention and elsewhere say the Thermopolis outbreak was the first serious investigation of a violent vertigo epidemic. Doctors have long thought viruses cause vertigo in some cases, but the Thermopolis incident, coupled with an outbreak at an Atlanta clinic last summer, helped them narrow down the link.

“This is the first study that really corroborates the role of a virus in epidemic violent vertigo . . . that viruses that go to the inner ear, as opposed to viruses that go to the sinus, are out there and can cause inner-ear problems,” said Arenberg, of the International Meniere’s Disease Research Institute.

Arenberg, one of the authors of a report about the case, said the outbreaks appear to have been caused by an enterovirus, a family of viruses whose members can cause polio and meningitis.

The discovery could be good news to millions of Americans who suffer from vertigo or similar but more severe diseases, officials say.

“I was surprised to learn how common vertigo was,” said Dr. Scott Dowell, a CDC epidemiologist. “We found lots and lots of cases. But I think there are many different things that can cause vertigo. The one we’re interested in happens in clusters.

“In these two clusters there weren’t deaths. Most people were back to their normal selves in weeks or a couple of months at least,” he said. “But it can be pretty debilitating while you have it.”

Scientists found antibodies against enterovirus when examining the Thermopolis outbreak. The outbreak in Atlanta, which affected 27 people at an unidentified clinic, helped them gather specimens to grow an enterovirus that is still too vague to distinguish among the 70 or so sub-types.

With the Thermopolis outbreak, researchers were open to any cause, from mass hysteria to environmental exposure, said Dr. Lone Simonsen of the CDC.

The town of 3,200 is an isolated mountain community in central Wyoming, home to what is billed as the world’s largest mineral hot springs. Researchers looked at the springs as a common connection, but quickly ruled it out.

“For the Chamber of Commerce’s sake, it’s not something you have to avoid Thermopolis for,” said Dr. Howard Willson, Belinda’s husband.

In fact, Simonsen stressed that Thermopolis was only where scientists caught up to the disease.

“It doesn’t mean the outbreak was confined to the place,” she said. “It’s possible it was going on all over the Rockies or all over the mid-American states.”

Thermopolis’ isolation was a blessing. Information was able to be gathered in a timely fashion, and the people were eager to help, Simonsen said.

Arenberg said the information opens up a whole new field into the study of more chronic ear diseases such as Meniere’s, which affects nearly 7 million Americans and is often misdiagnosed. The painter Vincent van Gogh, for instance, suffered from Meniere’s but was thought to be epileptic or insane.

Arenberg guesses, from anecdotal information, that one-third of violent vertigo patients develop Meniere’s disease. Belinda Willson hopes she is not among them.

She said ear patches used for seasickness helped her ease the nausea, spinning sensations and other symptoms that gradually decreased in severity. The vertigo has only recurred occasionally and never in such intensity, she said.