Clinicians Dissect Dizziness

SAN DIEGO—A 69-year-old man recently came to see Yuri Agrawal, MD, MPH, associate professor of otolaryngology at Johns Hopkins University in Baltimore, with chronic dizziness and a history of superior semicircular canal dehiscence (SSCD) that was repaired in a 2015 procedure.

The man’s vertigo resolved four months after the 2015 procedure, but he then developed chronic dizziness, unsteadiness, and gait impairment that caused him to veer to his left. He’d fallen several times, and more falls were his biggest concern. His dizziness wasn’t typical of canal dehiscence, he still had vestibulo-ocular reflex (VOR) gain at 0.81, despite what appeared to be plugging of the superior canal space, and he had a persistent air-bone gap.

The complex case was presented here in January at the Triological Society Combined Sections Meeting in a kind of adventures-in-dizziness session that put clinicians to the test.

Basics First

Dr. Agrawal’s case was an illustration of why it is important to go back to basics when confronted with unusual symptoms. Her team had to revisit “first principles and consider the canal anatomy and physiology,” she said.

The atypical dizziness for an SSCD case, they reasoned, could have been due to the plug migrating to the wider section of the superior and horizontal canals near the utricle, where it could cause a constant deflection of the cupula, triggering an acceleration stimulus perceived by the brain. The result is dizziness, Dr. Agrawal said.

They also found it odd that the patient’s eye movements mostly remained in sync with his vestibular system, even though it looked like his superior canal was plugged. But a 2017 study (Biophys J. 2017;113:1133-1149) holds a reasonable explanation: While the plug can be enough to prevent endolymph from flowing during slower head movements, faster head movements can cause a distension of the membranous duct.

As for the persistent air-bone gap, Dr. Agrawal said, the migration of the plug could have led to exposure of the initial dehiscence or to a new, persistent dehiscence.

The patient went through multiple courses of vestibular therapy with no improvement. He is now considering replacement surgery, including removal of the existing plug. That calls for careful patient counseling, Dr. Agrawal said.

“When you’re signing up for a revision plugging, you have to indicate to the patient that they may end up with a functional labyrinthectomy at that time, and there is some potential risk to their hearing as well. That may be a more desirable state than the patient is in, if they are having incredibly disabling symptoms,” she said. “I think it’s an interesting case of just thinking about the surgical approach, the anatomy of the dehiscence, what might be some of the consequences for that, and what might be ways to manage that.”

Odd Symptoms Among Military Members and Family

Michael Hoffer, MD, professor of otolaryngology and neurological surgery at the University of Miami, described his investigation of an odd constellation of symptoms experienced by U.S. military and family members stationed in Havana, Cuba, in 2016 (Laryngoscope Investig Otolaryngol. 2018;4:124-131; https://doi.org/10.1002/lio2.231).

First one service member, and then many more, reported ear pain, ringing in the ear, dizziness, and cognitive problems. They all experienced a loud noise before and during these symptoms. The sound was localized and, the patients said, it “followed” them around, but would stop immediately if the door to the outside was opened.

When you’re signing up for a revision plugging, you have to indicate to the patient that they may end up with a functional labyrinthectomy at that time, and there is some potential risk to their hearing as well. —Yuri Agrawal, MD, MPH

The 25 people who had exposure and symptoms were evaluated and compared to 10 people who heard no noise and felt no pressure even though they were in the same dwelling at the time. Unaffected Cuban embassy occupants, selected by the embassy, were also evaluated.

Researchers only collected data that was considered relevant after a physical exam. Dr. Hoffer emphasized that the 25 symptomatic patients in this evaluation were evaluated quickly and not influenced by media reports or efforts to get workers’ compensation.

Subjective visual vertical (SVV) tests were abnormal in 88% of the patients. The 12 patients who had vestibular evoked myogenic potential (VEMP) testing had abnormal results on either the cervical or ocular part of the test.

Dr. Hoffer also conducted testing on the eyes’ converging and diverging and observed how the patients’ pupils responded to light. The results, he said, clearly distinguished among normal controls, normal controls with mild traumatic brain injury (TBI), and people affected by the incident in Havana.

“The Havana-affected individuals looked nothing like the TBI subjects, which caused most of the world to shift and say, ‘Well, this is not TBI; this is something different,’” he said.

Researchers are still not sure of the diagnosis. It’s being described as an “acquired neurosensory dysfunction” that universally affects the interpretation of equilibrium and with other vestibular findings (Laryngoscope Investig Otolaryngol. 2018;4:124-131; https://doi.org/10.1002/lio2.231).

The cognitive issues could stem from the vestibular problems, but it’s also possible that the brain itself has been affected, Dr. Hoffer said.

“The site of injury could be the ear alone, or it could be the whole brain,” he said. “But it’s a real physiological disorder in those individuals (who) are truly symptomatic.”

Three Years with Dizziness

Peter Weisskopf, MD, assistant professor of otolaryngology-head and neck surgery at Mayo Clinic in Phoenix/Scottsdale, Ariz., described a 67-year-old woman who came to him complaining of three years of dizziness. She handed him a binder logging her symptoms by date and told him he was “the only one who can help me.”

Dr. Weisskopf diagnosed her with persistent-postural and perceptual dizziness (PPPD), the second most common diagnosis seen in tertiary neurotology clinics. The condition can be chronic and disabling when it is missed, but treated successfully when it is caught, Dr. Weisskopf said.

PPPD involves dizziness, unsteadiness, or both for most days over three months or longer. The symptoms are there without a specific trigger, but can be made worse with an upright posture and exposure to moving visual stimuli. It also usually starts shortly after an event that causes acute vestibular symptoms, and the symptoms can’t be attributed more reasonably to some other disease or disorder (J Vestib Res. 2017;27:191-208).

Selective serotonin reuptake inhibitors, selective serotonin-norepinephrine reuptake inhibitors, physical therapy, and patient education are part of the treatment strategy, Dr. Weisskopf said.

Red flags that a condition is likely not PPPD, he said, include progressive symptoms that worsen over the course of years, an onset that’s indistinct, and symptoms that are constant regardless of factors that might bring them on.

Dr. Weisskopf said clinicians should remain aware of the possibility of PPPD.

“It’s actually tremendously common,” he said. “It’s just something that’s sort of easy for people to wave away.” 

---

Thomas R. Collins is a freelance medical writer based in Florida.