Vestibular Care Path and Modifications to Standard Procedures Based on Patient Age

Vestibular Care Path and Modifications to Standard Procedures Based on Patient Age

REVIEW

Selection of vestibular services should reflect justification of medical necessity to render diagnosis and treatment planning (Centers for Medicare & Medicaid Services, n.d.). A thorough case history (Chapter 2) and direct office “bedside” examination (Chapter 3) is needed to guide in the test selection process. Vestibular tests are then selected to support clinical hypotheses developed during the initial consultation (Shepard & Telian, 1996). The objective tests aid in differentiating peripheral versus central cause to account for symptoms and signs. The unique combination of video head impulse testing (VHIT; Chapter 7), vestibular evoked myogenic potentials (VEMPs; Chapter 8), and gold standard vestibular measures of caloric irrigations, which is part of electronystagmography/videonystagmography testing (ENG/VNG; Chapter 5) and rotational chair testing (RCT; Chapter 6) allow for topographical evaluation of the vestibular apparatus (Jacobson, Piker, Roberts, McCaslin, & Ramadan, 2021; Table 10–1). Finally, the inclusion of Computerized Dynamic Posturography (CDP; Chapter 9) helps to quantify sensory integration and the patient’s functional capabilities. While these statements support routine inclusion of vestibular measures, formal testing may not be necessary or recommended in all patient cases (e.g., benign paroxysmal positional vertigo [BPPV]; see Chapter 4). Figure 10–1 provides an example vestibular care path decision tree.

Table 10–1. Vestibular Structures and Reflexes Evaluated in the Vestibular Laboratory

Note: VOR = vestibulo-ocular reflex, VCR = vestibulo-collic reflex, vHIT = video head impulse test, VEMP = vestibular evoked myogenic potentials

Source: Modified from Balance Function Assessment and Management, Third Edition (pp. 251) by Gary P. Jacobson, Neil T. Shepard, Kamran Barin, Robert F. Burkard, Kristen Janky, and Devin L. McCaslin. Copyright © 2021 Plural Publishing, Inc. All Rights Reserved.

VESTIBULAR EVALUATION CONSIDERATIONS: GERIATRICS

The symptom profile for older patients presenting to the vestibular clinic commonly includes lightheadedness, dizziness and imbalance, which may be linked to age-related sensory decline, polypharmacy, deconditioning, and other comorbidities (Harris, Barin, & Dodson, 2018; Meldrum & Hall, 2021). Symptoms affecting neurologic and cardiovascular function escalate falling risk in this population. Fatal and nonfatal fall injuries attribute to substantial medical expenses (Florence et al., 2018). Injuries sustained from falls may heal, but the psychological consequences (e.g., fear of falling) lead to further decreased physical condition and risk of future falls.

Hearing loss is associated with self-reported falls (Criter & Honaker, 2013). The link between hearing loss and falls may be due to co-existing vestibular pathology given the shared structures within the labyrinth and VIII cranial nerve. The incidence of BPPV increases substantially with age (Neuhauser & Lempert, 2009), and vestibular anomalies may be an unacknowledged contributor to falling risk in older adults (Jacobson, McCaslin, Grantham, & Piker, 2008). Recently defined by a subcommittee of the Bárány Society’s Committee for Classification Vestibular Disorders, presbyvestibulopathy (PVP) is a “chronic vestibular syndrome characterized by unsteadiness, gait disturbances, and/or recurrent falls in the presence of mild bilateral vestibular deficits” (Agrawal et al., 2019, p. 162). Pertinent findings on laboratory tests range from normal values to thresholds established for bilateral vestibulopathy (Agrawal et al., 2019). Evaluation of the elderly patient with imbalance and/or falls thus includes vestibular assessment to monitor for age-related degeneration of the peripheral vestibular system.

Figure 10–1. Example vestibular assessment care path.

PVP requires meeting all Bárány Society criteria:

• Patient’s age ≥60 years

• Patient presents with chronic (three or more months) vestibular syndrome including at least two of the following symptoms:

○ postural imbalance

• gait disturbance

○ recurrent falls

○ dizziness

• Reduced bilateral vestibular function documented on one of the following objective measures:

○ VHIT gain between 0.6 and 0.8 bilaterally

○ RCT sinusoidal harmonic acceleration (SHA) gain value between 0.1 and 0.3 at 0.01 Hz

○ Bithermal caloric irrigation total (right ear and left ear) peak slow phase velocity responses between 6 and 25°/second

• Symptoms may not be explained by comorbid factors

Components of the Geriatric Vestibular Evaluation

1. A detailed case history with questions pertaining to falling risk (see Chapter 2) should be included. A recent systematic review by Lusardi et al. (2017) evaluated the predictive ability of 15 case history questions to assess falling risk. The authors found that no single question was powerful enough to predict falls; however, these five questions were useful in determining the need for additional testing:

• Have you experienced any previous falls?

• Do you require activities of daily living (ADL) assistance?

• Do you use an ambulatory device?

• Do you have a fear of falling?

• Are you currently taking any medications for depression or anxiety?

2. Vestibular “bedside” examination (see Chapter 3) is conducted with the additional measures to assess for falling risk. The Centers for Disease Control and Prevention (CDC) includes the Timed Up and Go Test or TUG (Podsiadlo & Richardson, 1991) in the Stopping Elderly Accidences, Deaths, & Injuries toolbox (CDC, 2017). The TUG measures in seconds the time for a patient to rise from a standard arm chair, walk three meters, turn, and walk back to sit down in the chair. Older adults who take ≥ 12 seconds to complete this task are at increased risk of falling (CDC, 2017).

3. CDP is recommended to evaluate sensory contributors to balance and motor function (see Chapter 9).

4. Screening for BPPV is warranted (see Chapter 4).

5. Formal vestibular testing, including caloric irrigations (part of ENG/VNG), RCT, VHIT and VEMPs are then endorsed (see Chapters 5, 6, 7, and 8). Note: VEMP amplitudes decrease with advanced age (Piker, Jacobson, Burkard, McCaslin, & Hood, 2014); however, additional testing at 750 or 1000 Hz may aid in monitoring otolith decline in older adults.

6. Finally, the central vestibular system should be evaluated for age-related changes to the oculomotor system (Chapter 5).

VESTIBULAR EVALUATION CONSIDERATIONS: PEDIATRICS

Implications of Vestibular Impairment

Vestibular loss that occurs congenitally or acquired early in growth directly impacts balance and gross motor development (Janky, Thomas, High, Schmid, & Ogun, 2018; Maes et al., 2017; Rine et al., 2000). Children with vestibular loss present with specific problems (Christy, 2021; Janky & Shepard, 2021):

• Difficulty sitting unsupported, standing and walking

• Poor gaze stabilization/visual acuity with dynamic head movements

• Clumsiness

• Impaired spatial navigation

• Problems with childhood activities (sports, riding a bike)

• Dizziness, vertigo, imbalance, and oscillopsia

• Hearing loss

• Headaches

Delays in acquiring head control and the ability to stand and walk independently are closely linked to children with significant hearing and vestibular impairments (Inoue et al., 2013; Janky, Thomas et al., 2018). Janky, Thomas et al. (2018) retrospectively reviewed the factors for children with hearing loss that would predict vestibular impairment. The necessity to refer a child for vestibular evaluation is high when the following factors are present: (1) pure tone average (PTA) hearing loss > 66 dB, (2) ability to sit independently > 7.25 months or age-to-walk > 14.5 months, and (3) parental/caregiver expressed concerns with gross motor development (Janky, Thomas et al., 2018). If vestibular loss is diagnosed, management techniques (e.g., vestibular rehabilitation should be initiated (see Chapter 11). Vestibular rehabilitation is shown to improve gaze stability/visual acuity concerns, balance, and gross motor delays (Christy, 2021).

In addition to hearing impairment, vestibular loss is closely linked to the same etiologies as adults; however, vestibular migraine and benign paroxysmal vertigo of childhood are the most common (Davit, Delvecchio, & Aronoff, 2017). These migraine variants present with sudden, albeit brief episodes of vertigo and associated symptoms of nausea and vomiting. Table 10–2 provides a breakdown of both in utero and acquired disorders leading to vestibular impairment: for full discussion, please refer to Janky and Shepard (2021).

Aspects of the standard vestibular test battery may be applied to children (Ciolek et al., 2018), with understanding of maturational effects of the balance system. The ability to fully integrate balance sensory systems assisting in tasks such as postural control develops slowly and does not approach adult performance until approximately 15 years of age (Janky & Shepard, 2021). Oculomotor testing may be performed in children; however, performance is variable in children <7 years potentially due to the attention to task required for evaluation. Similarly, the vestibulo-ocular reflex (VOR) is intact by birth, yet there are challenges evaluating the reflex response in children with standard vestibular testing (e.g., caloric irrigations). Maturational and patient factor (e.g., attention, fatigue) considerations should be given to all pediatric patients, with special emphasis on making the test fun and of interest to young patients <7 years of age (Janky & Shepard, 2021). Reinstruction and reassurance is needed throughout all portions of testing.