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Classifications and definitions are essential to facilitate communication between clinicians and researchers and promote diagnostic criteria and research in mechanisms epidemiology and treatment.
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To build the International Classification of Vestibular Disorders (ICVD), the Bárány Society organized a systematic internal process and processes for encouraging consensus with other scientific societies.
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The ICVD is organized in 4 layers: (1) symptoms and signs, (2) syndromes, (3) disorders and
Overview of the International Classification of Vestibular Disorders
Section snippets
Key points
Goals and scope for the International Classification of Vestibular Disorders initiative
The goal of the ICVD initiative is to develop a comprehensive classification scheme and definitions of individual vestibular diseases disorders that is acceptable worldwide. To achieve the goal of wide acceptance, the Bárány Society is actively seeking the input of members from other associations dealing with vestibular disorders, such as the Société Internationale d’Otoneurologie and the Comisión de Otoneurología de la Sociedad Española de Otorrinolaringología in Europe, the American Academy
Methodology and process for developing the International Classification of Vestibular Disorders
In 2006 the Classification Committee of the Bárány Society (CCBS) convened its first meeting to begin structuring the approach to developing the ICVD. The group needed to develop a conceptual framework, a list of initial topics, and a process for consensus building. To permit terminological consistency in defining vestibular disorders as part of the ICVD, it was decided to first define key vestibular symptoms and build consensus around these formalized definitions (Boxes 1 and 2); the product
International Classification of Vestibular Disorders structure
The proposed structure of the ICVD currently includes 4 layers. Layer I, symptoms and signs; layer II, clinical syndromes; layer III-A, diseases and disorders; and layer III-B, pathophysiologic mechanisms (Fig. 1). Each layer contains elements (eg, specific symptoms or diseases) that are important in their own right, but are also important in their links with other elements. This structure will allow the ICVD to depict conceptual connections between elements within and across layers. Because
International Classification of Vestibular Disorders layer I: symptoms and signs
Definitions for specific vestibular symptoms in layer I of the ICVD have been written and published.5 Work is underway on specific signs, particularly pathologic eye movements. This layer was addressed first because it was considered foundational to the development of all subsequent definitions, the vast majority of which will be based on clinical phenomena. It was decided to limit the scope of this work to defining cardinal vestibular symptoms, representing the primary clinical symptoms
International Classification of Vestibular Disorders layer II: syndromes
Layer II, syndromes, offers an intermediate layer of syndromic classification that bridges between constellations of symptoms and signs and the diseases or disorders causing them. For example, sudden-onset vertigo, nausea, vomiting, head motion intolerance, gait unsteadiness, and nystagmus would constitutive an “acute vestibular syndrome” that has underlying causes, such as vestibular neuritis and acute cerebellar infarction. Currently proposed are 3 specific syndromes comprising the bulk of
International Classification of Vestibular Disorders layer III: disorders and diseases
Layer III-A contains vestibular diseases and disorders and seeks to be relatively comprehensive. The ICVD will use existing terms for vestibular disorders and diseases wherever possible. New terms will be developed only for conditions not included in previous classifications or, rarely, for conditions having multiple names that are all incompatible with ICVD nomenclature. If several existing names are used to describe the same condition, the CCBS will endeavor to include the most suitable one
International Classification of Vestibular Disorders layer III-B: mechanisms
Layer III-B contains the pathoanatomic, pathophysiologic, and etiologic mechanisms underlying vestibular disorders. It is anticipated that this layer will be developed last and will be the most incomplete in the first iteration of the ICVD, but will expand and grow the most with future scientific discovery. This layer has been created with the knowledge that, eventually, clinical phenomena (ie, symptoms and signs) may be linked directly with mechanistic understanding (eg, genetic mutation) for
International Classification of Vestibular Disorders and functional outcomes
Finally, it is recognized that the functional impact of vestibular diseases and disorders is substantial and that a schema for standardized assessment of disability or handicap is needed. A diagnosis itself does not provide information about functional consequences for the affected individual. The World Health Organization has created the International Classification of Functioning, Disability and Health, which describes the adverse effect of disease on daily activities and makes the assessment
Summary
An initiative under the aegis of the CCBS is currently underway to develop a comprehensive classification structure and formal definitions for vestibular symptoms, syndromes, and diseases. The success of the ICVD will depend on its ability to improve communication among scientists, clinicians, patients, policymakers, and the general public, to advance knowledge about vestibular disorders, and to reduce the morbidity of those afflicted by the conditions it defines.
Acknowledgment
Dr Newman-Toker's effort was supported, in part, by a grant from the National Institutes of Health, National Institute on Deafness and Other Communication Disorders (1U01DC013778-01A1).
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