Chapter 8: Examination and Evaluation of Vestibular Function

Chapter Objectives

Upon completion of this chapter, the learner should be able to:

1. Describe the key aspects of anatomy and physiology of the vestibular system and the implications of specific disorders.

2. Describe the normal functions of the vestibular system.

3. Analyze clues from the medical history and clinical examination findings to differentiate between peripheral and/or central dysfunctions.

4. Select appropriate vestibular testing methods for a given patient scenario.

5. Differentiate normal from abnormal on the vestibular examination tests and measures.

6. Explain specific vestibular test results and implications for treatment decisions.

Introduction

The vestibular system is the sensory system that plays a dominant role in postural control, eye-head coordination, and perception of our orientation in space. Dysfunction in the vestibular system may result in unsteadiness, dizziness, and/or misperceptions about movement of the body or head in space. Dizziness and balance disorders are a frequent complaint to physicians (Maarsingh, 2010; Jonsson, 2004; Tinetti, 2000; Sloane, 2001). One large epidemiological study reported an estimated 69 million Americans have experienced some form of vestibular dysfunction (Agrawal, 2009). Studies also show dizziness is the third most common complaint to physicians (Warner, 1992), and in 85% of patients reporting these symptoms, the cause is vestibular dysfunction (Guzmán, 2001). Balance impairment is one of the most important risk factors for falls and injuries. From 1999 to 2013, more than 25,000 fall deaths occurred among people ages 65 and older resulting in the leading cause of death due to unintentional injury in the United States (CDC, 2015). Research shows declines in balance occur even in the context of typical geriatric pathological changes. Hip fractures are the most common result from a fall (Parkkari, 1999), however, the elderly rarely report falls to caregivers or family (CDC, 2003). One of the most difficult issues facing health-care providers is formulating an accurate diagnosis and effective treatment plan. Part of the challenge is that dizziness is a vague term and does not provide the examiner with any specific information about the possible pathology. Dizziness is also a common symptom secondary to a number of disease processes and is one of the most common side effects of prescription medication. Even outside the context of the effect on balance, vestibular dysfunction can result in significant fear and avoidance and even emotional distress associated with activity and participation restrictions (Yardley, 2004; Hillier, 2011) that limit an individual’s engagement in society and life roles. Therefore, an efficient and effective examination is essential to identify appropriate interventions to restore activity and participation.

The purpose of this chapter is to discuss the clinical examination and evaluation of individuals with vestibular disorders. Key aspects of anatomy and physiology of the vestibular system are reviewed as well as the effect of common vestibular disorders and the most important tests and measures. By the end of this chapter, the reader should be able to analyze clues from the medical history and clinical ...