The dangers of concussions, caused by traumatic stretching and damage to nerve cells in the brain that lead to dizziness, nausea and headache, has been well documented. But ear damage that is sometimes caused by a head injury has symptoms so similar to the signs of a concussion that doctors may misdiagnose it and administer the wrong treatment.
A perilymph fistula is a tear or defect in the small, thin membranes that normally separate the air-filled middle ear from the inner ear, which is filled with a fluid called perilymph. When a fistula forms, tiny amounts of this fluid leak out of the inner ear, an organ crucial not only for hearing but also for balance.
Losing even a few small drops of perilymph leaves people disoriented, nauseous and often with a splitting headache, vertigo and memory loss. While most people with a concussion recover within a few days, a perilymph fistula can leave a person disabled for months.
There is some controversy around perilymph fistula due to its difficulty of diagnosis — the leak is not directly observable, but rather identified by its symptoms. However, it is generally accepted as a real condition by otolaryngologists and sports physicians, and typically known to follow a traumatic event. But concussions — as well as post-concussion syndrome, which is marked by dizziness, headache and other symptoms that can last even a year after the initial blow — also occur as the result of such an injury.
The concern about misdiagnosis is that while post-concussion syndrome has no specific treatment to cure it, a fistula can be repaired surgically with tissue grafts, in most cases restoring a person’s health quickly.
“Are there milder cases [of perilymph fistula] that we’re just not recognizing and labeling as post-concussion syndrome? It’s an interesting question, and I don’t think anybody knows,” said sports medicine physician J. Herbert Stevenson of the University of Massachusetts Medical School.
Some head trauma patients had been assumed to have post-concussion syndrome and only after several months of suffering were discovered to have a perilymph fistula. They then undergo the surgery, and a large majority recover.
“Perilymph fistula is a very unusual condition, and it can create very confusing pictures of dizziness,” said pediatric neurologist Christopher Giza, who heads a UCLA program that focuses on sports concussion prevention, research and treatment. “It’s hard to diagnose.”
Beyond head trauma, which studies suggest is responsible for 30 to 60 percent of diagnosed cases, other possible causes include acoustic trauma from an explosion or gun fired near the head, overexertion during weightlifting or childbirth, and barotrauma from flying or diving that causes unequalized air pressure. Giza estimates that perhaps only 1 percent of his patients had symptoms — vertigo, for example — that hinted at a perilymph fistula.
In March 2012, Stephen Bonacci, then a freshman at Langley High School in Fairfax County, got hit in the head while playing lacrosse. As he attempted a shot with two minutes left in the game, Bonacci suddenly felt some part of the goalie’s body hit him hard in the left temple. Bonacci was wearing a helmet, but it was a borrowed one that did not fit quite right.
“From there, my entire neck just kind of snapped. I didn’t hit the ground and didn’t lose consciousness, so I kept playing,” said Bonacci, now 18. “At the buzzer, I remember feeling dizzy.”
The next day, he woke up still dizzy and with an excruciating headache. He found himself unable to focus and visited the school’s athletic trainer for help. Cognitive tests revealed that his memory and concentration were well below his preseason levels. About four weeks later, he was told by a sports medicine specialist that he had a concussion with a vestibular, or balance-affecting, component. He was pulled out of school for the rest of the year.
In the months that followed the injury, Bonacci recalls, he went from being an athletic, outdoors-loving kid to a hermit shuttered away in his family’s basement. His disorientation got so bad that in order to walk down a hallway without stumbling, he had to use the walls on either side. He was afraid to walk outside by himself, for fear of falling down and passing out. Even reading was impossible: His eyes constantly pinged about, refusing to focus on a single line.
“It was terrible,” Bonacci said. “You look at the kids that are getting injuries like this, they’re all pretty serious athletes that love a sport, and all of a sudden you go from being active to being a couch potato.”
At a dinner party almost a year after his concussion, Bonacci’s parents met a physician whose ears perked up when he heard about their son’s condition. Otologist and neurologist Dennis Fitzgerald of MedStar Washington Hospital Center, who has studied the causes of persistent dizziness after head trauma, brought him in for tests. In April 2013 — 13 months after his concussion — Bonacci was diagnosed with a perilymph fistula.
Controversy swirls around how to diagnose perilymph fistulas, which is a major reason the incidence of the disorder remains a mystery. Even surgically peeking into the middle ear to look for a tiny tear or hole hasn’t proved successful. Instead, vestibular, or balance, tests are used.
One of them is the electronystagmography exam, which tracks a patient’s involuntary eye movements. Normally, a person’s eyes can focus on an object even as his head moves around. When the head moves one way, the eyes move in the opposite direction to stay fixed on the object. Because the inner ear is responsible for sensing the position and angle of the head, eyes that fail to track properly may suggest a perilymph leak.
Another part of the exam uses sprays of cold or hot water into the ear canal to stimulate the acoustic nerve, which is involved in hearing and balance. The involuntary movements of the eyes in response to the rush of coldness or warmth can tell a practitioner whether the balance system is functioning properly or if there may be a perilymph fistula.
“The perilymph system is a fluidic system, similar to the brake system of your car. Most people know that if you don’t have fluid in your brake system, it isn’t going to work right,” Fitzgerald said. “A hydraulic system to work correctly has to be absolutely watertight, and even a minor leak in the system causes a dysfunction of the entire system.”
Our vestibular systems are constantly at work, keeping us from falling over while we stand, run or walk. The inner ear is particularly important for balance: It contains three fluid-filled semicircular canals that act as sensors. Each of these canals senses motion. Tiny hairs within the canals pick up on the sloshing liquid inside and send corresponding information to the brain.
Two thin membranes ordinarily prevent pressure changes in the middle ear — the area between the eardrum and the inner ear — from affecting the inner ear. These membranes cover openings, called the round and oval windows, between the two regions of the ear. A leak in or near these membranes, can create pressure changes that affect a person’s balance.
The surgery to fix a perilymph fistula involves grafting small pieces of tissue from the patient onto these windows to patch up any leaks. The procedure is done under general anesthesia in about 45 minutes. Someone with no leaks won’t feel any different afterward, but a patient with a perilymph fistula should notice improvement within a month. Fitzgerald said he has performed more than 1,200 of these operations, including one on Stephen Bonacci, with almost all patients experiencing a complete or near resolution of balance problems.
“My sense with perilymph fistula is that there’s actually quite a bit of vertigo with it, which is more atypical with post-concussion syndrome,” said Stevenson, who works as a sports team physician for five higher education institutions in Massachusetts. When athletes take a bad hit, he said, they usually “stagger off, but my sense is that vertigo is not all that common or particularly relevant to concussions.”
But Stevenson adds that we still don’t fully understand what concussion is and that it may encompass different injuries. “There’s not a one-size-fits-all for concussion symptoms because they involve diffuse areas of the brain,” said Giza. “They can involve a whole panoply of symptoms.”
As for Bonacci, his balance and mental focus slowly returned during the year after his surgery. Now a senior, he says he experiences glimmers of his injured state from time to time but mostly he feels like his old self.
Yet there are significant aftereffects. He can no longer participate in any activity that might harm his ear again, such as contact sports or deep-water diving. For a young, active person who relished anything that got his heart pumping — lacrosse, surfing, soccer, to name a few — such restrictions have been tough to bear.
But Bonacci started to hit the gym again to regain the strength he lost, and he remains an avid fisherman and skier. He also channels his competitive athletic instincts into golf, which he hopes to play at Dickinson College in Carlyle, Pa. He also keeps his love of lacrosse alive by coaching youth teams.
“I still get headaches every few weeks, [and] there are still times I have lapses in memory,” he said. “I’m as good as I’m going to get, and that’s a reality that I’ve had to face now.”
Kim is a freelance science journalist based in Philadelphia.