Dysphagia Following Stroke

Second Edition

A Volume in the Clinical Dysphagia Series

Stephanie K. Daniels, PhDMaggie-Lee Huckabee, PhD

v

Contents

Foreword by Jay Rosenbek, PhD xiPreface xiiiAcknowledgments xivAbbreviations xv

1 Introduction to Dysphagia and Stroke 1Overview of Stroke 1Dysphagia in Stroke 7Multidisciplinary Management of Dysphagia in Stroke 18

2 The Neural Control of Swallowing: From 21 Central to PeripheralMethods for Understanding Neural Control 23Higher Nervous System Control 27Brainstem Mechanisms 30Peripheral Neuromuscular Mechanisms 34

3 Normal Swallowing Anatomy and Physiology 43Defining Normal and Abnormal Swallowing 43Phases of Swallowing 44

4 Screening for Dysphagia in Acute Stroke Patients 55Background of Screening Swallowing in Stroke 55Components of a Good Screening Tool 57Models for Screening Implementation 62Implementation of a Nurse-Administered Swallowing 65 Screening ToolAvailable Swallowing Screening Tools 69

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5 The Clinical Swallowing Examination: 77 History and Patient InterviewIntroduction to the Clinical Swallowing Examination 77Patient History 78Patient and Family Interview 80

6 The Clinical Swallowing Examination: 85 Cognition and Communication AssessmentsThe Cognitive Assessment 89The Communication Assessment 93

7 The Clinical Swallowing Examination: 97 The Evaluation of the Oral MechanismStructural Integrity 97The Cranial Nerve Examination: Inferring Physiology 98Case Example 110

8 The Clinical Swallowing Examination: 115 Assessment of Oral IntakeExecuting the Assessment of Oral Intake 115Interpreting the Assessment of Oral Intake 120

9 The Clinical Swallowing Examination: 127 Predicting Dysphagia and AspirationThe Water Swallow Test 127The Clinical Swallowing Examination with a Focus on 131 Clinical FeaturesPredicting Dysphagia and AspirationThe Mann Assessment of Swallowing Ability 142

10 Adjuncts to the Clinical Swallowing Examination 145Pulse Oximetry 145Cervical Auscultation 147Cough Reflex Testing 148

contents vii

11 The Instrumental Examination: The 159 Videofluoroscopic Swallowing StudyThe Need for Diagnostic Specificity 159The Videofluoroscopic Swallowing Study 162

12 The Instrumental Swallowing Examination: 181 Evaluation of Swallowing Respiratory Coordination — An Auxiliary to the Videofluoroscopic Swallowing StudyExecuting the Evaluation of Swallowing Respiratory 182 CoordinationInterpreting the Evaluation of Swallowing Respiratory 184 Coordination

13 The Instrumental Swallowing Examination: 189 Videoendoscopic Evaluation of SwallowingExecuting the Videoendoscopic Evaluation of 190 SwallowingInterpreting the Videoendoscopic Evaluation of 196 Swallowing

14 The Instrumental Swallowing Examination: 201 Manometric Evaluation of SwallowingManometric Approaches 202Executing the Manometric Evaluation 206Interpreting the Manometric Evaluation 210Variables Influencing Pharyngeal Pressure 213 MeasurementWhat Can Discrete Sensor Manometry Offer to 215 Clinical Practice?

15 Professional Responsibilities: Dysphagia 221 Diagnosis in StrokeCase Example 224

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16 Diagnosis of Dysphagia in Stroke 227Oral Phase 229Pharyngeal Phase 234Oral and Pharyngeal Dysmotility in Stroke 240Summary 252

17 Diet Considerations: To Feed or Not to Feed 253An Overview of Options for Feeding the Patient with 253 DysphagiaNonoral, Enteral Feeding Options 255Decision Making for Nonoral Nutrition 258Free Water 264Summary 267

18 Compensatory Management of Oropharyngeal 269 DysphagiaPostural Changes 276Sensory Enhancement 279Volitional Control of Oral Transfer 285Breath-Holding Techniques 286Bolus Modification 289

19 Rehabilitation of Oropharyngeal Dysphagia 301Oral Motor Exercises 303Effortful Swallow 311Mendelsohn Maneuver 316Masako Maneuver 319Shaker Exercise 321Expiratory Muscle Strength Training 323Electrical Stimulation 326Shifting Paradigms: Central Modulation through 334 Intrinsic and Extrinsic InterventionThe Need for Intelligent Enthusiasm 339

20 Maximizing Rehabilitation Effectiveness 343Biofeedback Modalities in Dysphagia Rehabilitation 343Dose 357

contents ix

21 Medical and Surgical Management 361Medical Management 361Surgical Intervention 362

22 Lagniappe 365Management Effectiveness with Stroke Patients 365Reassessment 368Last Thoughts 370

References 377Index 425

xi

Foreword

Stephanie Daniels and Maggie-Lee Huckabee are rehabilitation sci-entists of the first order. They have spent portions of their profes-sional lives in both laboratory and clinic. For them, the person with dysphagia is not merely a set of structures and muscles working in disharmony. Treatment is not merely an array of mechanical manipu-lations. Evidence-based practice is not merely the data. Swallowing, they know, is influenced by the sight, smell, taste, and texture of food; by affect, experience, and expectation; by environment and need. Treatment is an often tumultuous, always complex set of inter-actions among two or more people. Evidence-based practice rests equally on evidence, clinical acumen, and what each patient wants and needs. They know that data have no frontal lobes.

The second edition of Dysphagia Following Stroke reflects who they are and what they want for their profession and the patients it serves. In the first edition’s Foreword, I said clinical gems could be found on every page, gems hardened by the pressure of scientific rigor and cut and polished by the authors’ clinical experiences. The second edition contains more gems, more resistant to cracking and chipping and with greater sheen. They have written a new chapter on screening, emphasizing its purposes, procedures, and data. Their chapters on rehabilitation are expanded and alone are worth this book’s cost. Their new content on neuromodulation in rehabilitation using modalities such as transcranial magnetic stimulation makes this a book for the future as much as for the present. The updated list of references is complete and an invaluable resource for readers interested in primary sources as a foundation for their clinical or

xii Dysphagia Following stroke

research efforts. In a chapter called “Lagniappe” — a little something extra — they offer tastings on items such as commercialization that may be honey to some and sea urchin to others. “Good on them.” Books are ideal environments for thoughtful discussions of complex and contentious issues.

Daniels and Huckabee ended the Preface of their first edition with a warning to me, the Dysphagia Series Editor, that they would never again write a book. I responded in my Foreword that if they continued to feel that way after the very real anguish of book writ-ing dissipated, their wishes would, of course, be honored. How-ever, having benefited from the usefulness of their first “practical sourcebook,” I ended my Foreword with the hope that they would reconsider. They have, and the second edition of Dysphagia Follow-ing Stroke is the result. Students, practitioners, and scientists may want to express appreciation. This is a book for the pocket and not the shelf.

Jay Rosenbek, PhDProfessor and clinician, University of FloridaEditor, Clinical Dysphagia Series

55

Screening for Dysphagia in Acute Stroke Patients

BackgrOuND Of ScreeNiNg SwaLLOwiNg iN StrOke

Early detection of dysphagia in acute stroke is critical, as it allows for immediate intervention, thereby reducing mortality, morbidity, length of hospitalization, and health care costs (Hinchey et al., 2005; Martino, Pron, & Diamant, 2000; Odderson & McKenna, 1993). As such, screening of swallowing has become best practice in the man-agement of stroke patients and is the important first step in the evaluation process of dysphagia in stroke (Figure 4–1). Screening can be defined as a brief assessment that is easy to administer and minimally invasive. No diagnosis is made with a screening. In the case of dysphagia, the purpose is to determine who is at risk for dysphagia and/or aspiration and consequently warrants referral to speech pathology. Screening results may be either positive or nega-tive. If the screening results are negative (i.e., individual passes), oral intake without any specific modifications can be ordered by other members of the multidisciplinary team, and referral to speech pathology for assessment of swallowing should not be needed. On the other hand, if screening results are positive (i.e., individual fails), the individual is made nil per os/nothing by mouth — NPO/NBM — including medication, and referral to speech pathology is expedited. It is important to note that compensatory strategies (pos-ture or diet modification) should not be implemented based on the results of a screening.

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screening For Dysphagia in acute stroke patients 57

When a formal swallowing screening is in place, morbidity associated with dysphagia decreases (Hinchey et al., 2005; Odder-son, Keaton, & McKenna, 1995), health care providers’ adherence to screening guidelines is improved (Hinchey et al., 2005), and there is earlier administration of first-dose aspirin (Power, Cross, Roberts, & Tyrrell, 2007). These findings have led to the inclusion of swallowing screening prior to the administration of food, liquid, or medication, including aspirin, in individuals presenting with stroke symptoms in the American Heart Association/American Stroke Association guide-lines (Adams et al., 2007). In accordance with this guideline, the Veterans Health Administration advocated that screening of swal-lowing be a quality performance measure in acute stroke (Bates et al., 2005). Moreover, the Office of the Inspector General issued Veterans Health Administration Directive 2006-032 mandating that the initial nurse assessment must include screening of swallowing. Similar guidelines are emerging or already exist in many other coun-tries and many other health systems. Completion of a swallowing screening prior to administration of oral intake was a Joint Com-mission–required performance measure for Primary Stroke Center Certification in the United States until 2010, when it was removed due to a lack of systematically defined standards for what constitutes a valid screening tool for swallowing (Lakshminarayan et al., 2010). The discontinuation by the Joint Commission, however, does not indicate that screening swallowing is no longer warranted. Rather, it suggests that further research is warranted and consensus on a swallowing screening tool (SST) should be determined.

cOMpONeNtS Of a gOOD ScreeNiNg tOOL

All good testing tools, whether diagnostic or screening, must be valid, reliable, and feasible. Validity of the SST is critical; however, since disciplines without expertise in dysphagia may be involved in

58 Dysphagia Following stroke

screening swallowing, issues surrounding education, sustainability of skills, and feasibility become of even greater importance.

validity

Validity is the degree to which a test measures what it is purported to measure (Sackett, Strauss, Richardson, Rosenberg, & Hayes, 2000; Streiner, 2003). In terms of dysphagia, the outcomes measured are risk of dysphagia and/or risk of aspiration. It must be remembered that aspiration is a result of dysphagia. Although aspiration is fre-quently associated with dysphagia, an individual may have signifi-cant dysphagia without aspiration. We would argue that optimally refined screening tools would identify individuals at risk for dys-phagia, not just aspiration.

In screening, validity is frequently measured in terms of sensi-tivity and specificity. Sensitivity is the probability that a clinical sign (e.g., cough with water) will be present given that an impairment (e.g., dysphagia) is present. High sensitivity yields low false negative results; that is, the clinician can be confident that most patients with dysphagia are identified. Conversely, if the SST has low sensitivity in predicting dysphagia, false negative rates will be high. Patients would have a negative screening, yet they would actually have swal-lowing problems. Specificity is the probability that a clinical sign will be absent given that an impairment is absent. A test with high specificity will have a limited number of false positive results; the majority of patients with negative screening results will not have dysphagia. Low specificity, however, would result in a high false positive result, with a large percentage of patients without dyspha-gia having a positive SST.

Ultimately, high sensitivity appears to be the most important feature in a stroke SST due to increased morbidity and mortality associated with dysphagia, which necessitates the requirement for low false negative results. Frequently, specificity will be sacrificed to

screening For Dysphagia in acute stroke patients 59

achieve high sensitivity; however, low specificity cannot be ignored. At a minimum, it can delay the receipt of medication and nutrition and lead to overreferral to speech pathology. At its most severe, it can result in the placement of unwarranted nasogastric feeding tubes, which are associated with medical complications (Ciocon, Silverstone, Graver, & Foley, 1988), particularly in individuals with acute stroke (Langdon, Lee, & Binns, 2009). Hence, accuracy in iden-tification of individuals with suspected dysphagia would logically appear greatest when using a tool with both high sensitivity and high specificity. If an SST with both high sensitivity and specificity cannot be identified, then these two measures must be balanced with the needs of the hospital. If speech pathology services are read-ily available on a daily basis, then high sensitivity may be favored over high specificity. If speech pathology services are limited — for instance, weekend coverage is not available — reduced specificity would not be acceptable.

Two other important factors in validity are positive predictive value and negative predictive value. Unlike sensitivity and specific-ity, which provide information concerning correct classification of individuals who do or do not present with a positive SST, predictive values deal with the proportion of individuals with or without a pos-itive SST who do and do not have dysphagia identified on an instru-mental swallowing examination (e.g., videofluoroscopic swallowing study [VFSS]). Positive predictive value is the probability of having the condition (e.g., dysphagia) if the screening is positive (i.e., fail the screening). Low positive predictive value indicates an increase in false positive results. Negative predictive value is the probability of not having the condition (e.g., dysphagia) if the screening is nega-tive (i.e., pass the screening). Low negative predictive value indicates an increase in false negative results. Predictive values are highly influenced by the prevalence of the condition (e.g., dysphagia) in the studied population. As with sensitivity and specificity, the higher the predictive value, the better. Last, one should consider likelihood ratios, primarily positive likelihood ratios greater than 1. A positive