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A novel video-goggle recording device that patients wore at home helped identify the etiology of acute vertigo episodes, a proof-of-concept study showed.

With video oculography goggles, patients were able to record nystagmus direction and velocity to help researchers more accurately diagnose episodic vestibular disorders, reported Miriam Welgampola, MD, PhD, of the University of Sydney in Australia, and colleagues in .

"Vertigo is common with a lifetime prevalence of about 30% and is disabling, treatable, and undertreated," Welgampola told 番茄社区. "This technique will promote early diagnosis and correct treatment."

Vertigo can be spontaneous (occurring at rest) or positional (triggered by changing head position). Meniere's disease and vestibular migraine are two frequent causes of recurrent spontaneous vertigo. Benign paroxysmal positional vertigo is a common cause of recurrent positional vertigo brought about by arching backwards or turning in bed. Observing eye movements during vertigo can help make a differential diagnosis, but patients don't always have an episode at the clinic, Welgampola noted.

In this study, researchers studied 117 people in Sydney with an average age of about 51 from 2014 to 2017. All patients had been previously diagnosed with Meniere's disease (n=43), vestibular migraine (n=63), or benign paroxysmal positional vertigo (n=7) and all were asymptomatic at recruitment. Participants were taught to use video oculography goggles to record eye movements at home during spontaneous and positional vertigo. Ictal eye videos were a mean duration of 199.8 seconds.

Videos helped separate vestibular migraine from Meniere's disease, and benign paroxysmal positional vertigo from other positional causes:

• Forty of 43 patients with Meniere's disease showed high-velocity spontaneous horizontal nystagmus; among them, video data produced an accurate diagnosis with a sensitivity of 95.3% and a specificity of 82.1%
• Spontaneous vertical nystagmus was highly specific (93.0%) for a diagnosis of vestibular migraine, but with low sensitivity (23.9%)
• Peak nystagmus velocity and decay of velocity separated benign paroxysmal positional vertigo from positional nystagmus of Meniere's disease and vestibular migraine with a sensitivity of 100% and specificity of 77.8%

In comparison, audio tests conducted near the beginning of symptom onset showed that a low-frequency hearing asymmetry was diagnosed in Meniere's disease with a sensitivity of 90.7% and a specificity of 91.1%.

"The value of this technique goes beyond making a specific diagnosis, as it contributes to our understanding on the pathogenesis of vestibular syndromes," observed Jorge Kattah, MD, of the University of Illinois College of Medicine in Peoria, who was not involved with this study.

"The quality of the eye movement recordings was precise enough to arrive to a diagnosis in about one-third of the patients," Kattah told 番茄社区. "Subsequent studies will enable clinicians to explore other causes of episodic vertigo, especially those related to transient ischemic attacks where a timely diagnosis could potentially lead to stroke prevention."

If this technique is disseminated widely, clinicians could capture nystagmus in many patients with common causes of vertigo and accumulate a large body of descriptive data, Welgampola noted. "We will acquire a clear understanding of distinctive nystagmus patterns, of what is typical and atypical of each disorder," she said.

"The technique will be applicable in general practice, emergency, and rural healthcare settings and can help experts provide better outreach services," she added. "In patients with rare causes of vertigo, the ability to capture acute ictal nystagmus will increase our understanding of disease mechanisms."

The study had several limitations, including possible sampling bias due to voluntary participation and lack of control for medication intake. A few people who were recruited had disabling vertigo (n=4) and did not feel well enough to wear the goggles. Others had minor vertigo episodes that they thought were too mild to record. This was a single-center study and results might not be generalizable to a larger population, the authors noted.

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