FOR MORE THAN TWENTY YEARS, Dallas radio personality Kevin McCarthy has made a respectable living simply by being in a good mood—and by rubbing it off on the rest of us. The 46-year-old KLIF-AM morning talk show host is perpetually sunny, the sort of person who’s difficult even to imagine sick. So when he came down with a debilitating illness in early l994, friends like me were not only sympathetic but also a little shocked, especially when we found out what ailed him. Thankfully, it wasn’t anything terminal; some might not even have called it serious. But it definitely was mysterious: Kevin had a bad case of vertigo.

Vertigo is one of those conditions with which most of us can claim only a passing familiarity. Something about dizziness and the sensation of falling from extreme heights. Heckuva Hitchcock thriller of the same name. Actually, vertigo—the word literally means “the hallucination of motion”—is the most dramatic of a family of infirmities involving the body’s equilibrium system. Some 20 million Americans suffer from balance disorders, which cause, among other things, about 200,000 hip fractures a year.

A sense of disequilibrium can be a secondary symptom of many other afflictions—hypertension, anxiety, eyesight problems—but can also be caused by a disruption of the normal operation of the inner ear, the tiny and exquisite set of organs within the temporal bone of the cranium that keeps our heads on straight. The inner ear has two main parts: the cochlea, which translates airborne sound waves from the middle ear into fluid-borne waves of energy, then transduces those waves into electrical impulses so sound can be interpreted; and the vestibular system, three fluid-filled semicircular canals that are responsible for our innate sense of balance. Because these structures are so minute, it is often difficult if not impossible to diagnose precisely how and where the inner ear might be affected.

The best known of the balance disorders is pure vertigo, the feeling that the room is spinning even when you’re standing perfectly still; it can be caused by an inflammation (a virus or other infection) or a structural defect (a tumor, an abscess, a traumatic injury) in the inner ear. My wife had a nasty case about a year ago, the result of an inner ear virus that shorted out her equilibrium system. Though she was laid up for about a week with acute nausea, the condition eventually passed and is not likely to recur.

Other disorders, however, are subtler, more chronic, and ultimately more insidious. Kevin McCarthy found that out the hard way during a drive home up the Dallas North Tollway on Saint Patrick’s Day 1994. “I felt just slightly dizzy,” he recalls, “like when you step off a ship onto firm ground. I was dissociated, and I had heart palpitations—it was like an out-of-body experience.” When he got home later that day, the sensation abated, but it returned a few days later with more intensity. After that it began to reoccur frequently, particularly when he had no visual frame of reference (say, whenever he drove on a freeway overpass). Eventually the attacks caused him to be so unsteady afoot that he had to stabilize himself on the nearest wall. That begat sometimes fierce bouts of nausea, which only heightened his anxiety.

Fearing a serious problem with his nervous system, Kevin visited a neurologist, who pronounced him sound after a high-tech exam. But the episodes continued, so he went to see an ear, nose, and throat specialist. The specialist concluded that Kevin was probably suffering from an inner ear virus and that, like my wife, he would have to wait it out. In the meantime, he gave Kevin a small dose of Valium to calm him down.

The Valium helped some, but the attacks of dizziness and nausea didn’t entirely relent—and they were beginning to take a toll on Kevin’s day-to-day life. Some days he just couldn’t get out of bed. The drive from his home in far north Dallas to KLIF’s studio near downtown was torturous. Occasionally, the vomiting was so bad that he would have to be hospitalized. He couldn’t decide whether it was better to be a little sick all the time or very sick when he least expected it. “I was sick of being sick,” he says. He was also sick from being sick. He began to lose the hearing in one ear. The vomiting had severely irritated his esophagus, forcing him to take acid inhibitors. And he grew so depressed that he went on Prozac. “All of which can have the side effect of making you dizzy and nauseous,” Kevin notes dryly.

By the end of spring—three months after the first attack—he’d had enough of waiting the alleged virus out and paid a visit to otolaryngologist William Meyerhoff, an internationally known expert in balance disorders at the University of Texas Southwestern Medical Center at Dallas. Meyerhoff put Kevin through even more tests and took an extensive medical history, hoping to find a head trauma or something similar that might have sufficiently disturbed his equilibrium. He suspected the problem was perilymph fistula, a tiny structural defect of the membrane that separates the middle and inner ear; it results in a damaging exchange of fluid between the two chambers and, consequently, the sort of disequilibrium that plagued Kevin.

Meyerhoff’s hunch was confirmed when Kevin’s evaluation was completed. The results of his magnetic resonance imaging showed an absence of disease and no larger structural defect. He had a hearing loss of the high and low frequencies only—a peculiar symptom of perilymph fistula. A highly refined test that measures the electrical impulses produced by the cochlea revealed the distinctive pattern of an inner ear suffering a fistular defect. Also, after much prompting, Kevin remembered falling in his kitchen a few years before. The impact had been strong enough to knock him out, which made it more than forceful enough to cause a crack in his delicate inner ear tissue. “One of the key parts of this diagnosis is that antecedent incident,” Meyerhoff says. “It can be a blow to the head or, frequently, undue intracranial pressure caused by sneezing, coughing, labor during childbirth, skin diving—even heavy lifting.”

Kevin went in for surgery in March 1995. The procedure, though centered on a delicate portion of the cranium, was relatively basic: Meyerhoff harvested tissue from beneath the earlobe and grafted it over the tear in the inner ear membrane. Everything went well—or seemed to—until Kevin was in recovery and began, as he puts it, “barfing my guts out.” It may have been a reaction to the anesthesia or merely one more episode of his chronic nausea. Either way, there was a good chance that the meticulous grafting was blown to smithereens.

For a couple of months, it seemed to have taken. Although Kevin had to perform his morning talk show from home during his recuperation, the tyranny of unsettling dizziness and nausea abated. “I’d still have occasional episodes of unsteadiness,” he says, “but I couldn’t tell if they were legitimate or psychological. Also, it took some time to retrain my brain.” Kevin is referring to the difficult reorientation process that balance disorder patients often endure after corrective surgery. “Essentially, three systems maintain our sense of balance: our inner ear, our eyesight, and our musculoskeletal system,” Meyerhoff explains. “If any one of the three goes out, you can limp along, but the other two have a heavy load to carry. When the system is restored, it takes time for the brain to trust its messages again.” Kevin, it turned out, had been depending on his eyesight for his sense of equilibrium for so long that it was taking his brain some time to depend on his inner ear again. In the meantime, he was given to infrequent, almost psychosomatic lapses into the old pattern.

And then, in June, it all came apart: Kevin’s malady revisited with a vengeance, confirming Meyerhoff’s suspicion that the first surgery had been sabotaged by the vomiting. The next month, Kevin checked in to Zale-Lipshy University Hospital at UT-Southwestern for another perilymph fistula operation. Meyerhoff pronounced the second procedure successful; no adverse reaction this time. But the emotional strain of two years of more or less constant sickness was beginning to weigh on Kevin’s psyche. He continued to be depressed, and the secondary ailments didn’t help; his esophagus problems became so severe that he twice had to undergo an endoscopy, a relatively uncomfortable examination of the interior of a hollow organ. And a new demon had slipped into the pathological pandemonium: high blood pressure. Kevin had no history of a blood pressure problem, and his private physician had made no formal diagnosis of hypertension. But apparently the physical and emotional stress of a lengthy illness had begun to take its toll on Kevin’s heart, causing occasional “spikes” in his blood pressure. His physician put him on hypertension medication, which solved the spiking problem, but it made him dizzy all over again.

Given the virtual pharmacy of medications he was now taking for his implacable infirmity, Kevin decided it might be best to ease up on the Valium. Unfortunately, he had become somewhat dependent on it. Feeling the same unsteadiness and nausea returning, he again visited his doctor, who confirmed that the symptoms were more a result of Valium withdrawal than a reappearance of the balance disorder. He switched Kevin to Librium, a gentler tranquilizer, and prescribed a gradual weaning schedule. By Christmas, when I saw Kevin at a party, he reported that he was fine and appeared to be his old cheery self.

Less than a month later, however, while he and his wife were at a Dallas Mavericks basketball game (Kevin also serves as the team’s public address announcer), he felt the same old symptoms—dizziness, disorientation, racing heart, light nausea, light-headedness—return with a fierceness that felt like an attack. As it happened, then—Mavericks president Norm Sonju’s guest that night was a cardiologist, and she rushed to examine Kevin in the team locker room. The cardiologist couldn’t tell if this particular onset had anything to do with continued balance dysfunction, but she did know that Kevin’s blood pressure, which measured 200 over 120, was dangerously high.

Kevin was treated and released and then visited a hypertension specialist. Episodic spikes of blood pressure can be benign and meaningless, but they also can be a sign of a structural defect in the vascular system, such as a collapsed artery or a malfunction of the adrenal gland. The doctor marched the beleaguered patient through yet another round of imaging tests. On one of them, Kevin’s renal artery didn’t show up, suggesting that it might have collapsed, causing the spikes in his blood pressure. Yet when two technicians probed for the artery on a subsequent angioplasty, they found it in perfect working order. Actually, Kevin’s entire vascular system was pronounced sound. He was told to clean out his medicine cabinet and take only two mild hypertension drugs.

That was January—the end, Kevin hopes, of a surreal journey that cost him and his insurance carrier about $100,000. The familiar symptoms have come back only once since then, and even Kevin can’t say whether they were the real thing or another flashback. “You stay sick for that long,” he says, “and you can become almost too alert for a return of the symptoms. I still have a checklist I run through in the shower each morning. Am I nauseous or dizzy? How’s my blood pressure? Do I feel steady on my feet? I guess you could get dizzy just from worrying about it.”