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The Enigma of Enlarged Vestibular Aqueduct Syndrome

Patients may hold the key to improving EVA diagnosis and outcomes

Innovations in Otolaryngology– Head & Neck Surgery -- Summer 2018

Todd Otteson, MD, MPH

Division Chief, Pediatric Otolaryngology, University Hospitals Rainbow Babies & Children’s Hospital; Associate Professor, Otolaryngology and Associate Professor, Pediatrics, Case Western Reserve University School of Medicine

Thanks to a special internet website portal and database developed at University Hospitals Rainbow Babies & Children’s Hospital, scientists and physicians are hoping to unravel mysteries of Enlarged Vestibular Aqueduct Syndrome, or EVA.

The rare anatomical malformation is a common cause of congenital deafness and hearing loss in children, affecting close to 200,000 people nationwide. The online database, formally known as, Enlarged Vestibular Aqueduct Patient Registry at UH Rainbow Babies and Children's Hospital (EVAR), is expected to lead to targeted research providing greater information about prognosis, hearing outcomes and recommended precautions to these individuals and their families.

UNANSWERED QUESTIONS
According to Todd Otteson, MD, MPH, Division Chief, Pediatric Otolaryngology and Arnold and Nancy and Tom Seitz Chair in Pediatric Otolaryngology at UH Rainbow Babies & Children's Hospital, the idea for the EVA registry emerged when the parents of one of his patients began searching the internet for information about the condition.

“They found very little that was helpful to them, but they did come upon another EVA-impacted family in New Jersey,” Dr. Otteson explains. “Together, the two families contributed seed money leading to both development of the registry [in 2016] and further funding of the project through other donors.”

The cause of EVA is not fully understood, although genetic and/or environmental factors are thought to be involved. Typically, the condition is revealed when hearing problems are noted by parents or by a failed hearing screen. In some patients, hearing loss is reported after flying in an airplane or suffering head trauma.

The specific anatomic abnormality is detected with a computed tomography (CT) scan or magnetic resonance imaging (MRI), and EVA is diagnosed by measuring the vestibular aqueduct in two locations. UH researchers were the first to correlate the size of the vestibular aqueduct with the severity of hearing loss. Their findings were published in the June 2017 issue of JAMA Otolaryngology - Head & Neck Surgery.

PATIENT-SUPPLIED DATA MAY YIELD NEW INSIGHTS
EVA has eluded comprehensive research strategies, limiting current knowledge to isolated clinical observations and a relatively small number of findings. Using electronic patient health record (ePHR) systems and patient questionnaires, however, EVA registry data can provide new pathways for classification, clinical management and treatment of the condition. Audiograms and imaging studies can be securely added to the EVA registry, as well.

With rolling enrollment, Dr. Otteson notes that hopes are high that the registry can continue to add information on any new cases and become a valuable tool for scientists, physicians, patients and parents to collaboratively increase understanding of the condition.

The web portal was developed by Case Western Reserve University clinical researcher, Mustafa Ascha, MS, and the University Hospitals Information Technology Department under the auspices of the University Hospitals ENT Institute’s, Center for Research, which promotes translational and clinical research.

The EVA registry is a timely endeavor because interest in EVA-related hearing loss is growing and because ePHRs make patient data easier to access. At the same time, studies and published papers on the epidemiology of EVA and associated abnormalities are contributing to the body of literature studying diagnostic and classification criteria. For the first time, data will be available for answering questions about how common activities, such as swimming and air travel, may affect EVA patients and even the treatment contraindications for head injuries.

Another promising development is the World Health Organization’s proposal to add new EVA-relevant diagnosis codes to the 11th revision of the International Classification of Diseases (ICD). Dr. Otteson says of the diagnosis codes, “This is a watershed moment for EVA research and could significantly speed up EVA patient identification for research purposes.”

The EVA registry has taken off. So far, 45 individuals have completed the survey, while another 40 have entered partial data. The ePHRs for 35 Rainbow Hospital patients are in the system, as well. News of the registry continues to be disseminated publicly and via physician and research channels.

A COMMUNITY OF SUPPORT AND RESEARCH
The UH Rainbow Enlarged Vestibular Aqueduct Research Project is made possible through contributions from more than 100 donors, including friends, family members and supporters in the EVA community. The project is a donor-supported program.

EVAR’s data set may be provided to researchers interested in analyzing repository data. The limited data set does not contain any identifiable information except for details such as age and date of diagnosis.

For more information on the EVA registry or to help a patient enroll, please visit www.uhhospitals.org/rainbow/services/otolaryngology/eva-research-project.